Help me construct a fair test of nails
If you haven’t caught some of the various screw vs. nail threads over the last few months, well here is your chance to catch up on the action.
Last summer I constructed an experiment to test out what I had been hearing over and over, that due to lower shear strength screws could not be used to face nail metal joiners, such as joist hangers for instance. I devised an experiment, and ran it on a variety of nails and screws.
A few people here disagreed with the results of those tests. The results were so dramatic that the tests themselves were called into question. Fair enough. I would like to run a new battery, but devise them in such a way that they satisfy the critics of my first rounds.
So if you didn’t think I ran a good test before, help me create a new test or tests that will evaluate the ability of an individual fastener to hold a metal strap against a shear load.
To get the ball rolling, here is my first proposal, subject to refinement:
Purpose of Test: To find out how much of a shear load a variety of fasteners can
Materials used: 16ga. Simpson strap, 4×4 minimum board for fasteners over 1.5″ long, 2×6 for fasteners 1.5″ or less. Wood is green Douglas Fir.
Fastening method: Nails to be evaluated will be driven into the wood so that the head securely holds the metal to the wood. For primary testing no more than 3 blows will be used to drive in a nail.
A comparison of these results will be made by testing nails driven with a palm nailer and an inexperienced nailer who will use more than 3 blows to sink a nail. Comparisons will also be made using a variety of screws that will be driven until the head seats the metal strap against the wood. In these tests, the nails and screws may have a pilot hole drilled, if so it will be documented.
Testing method: The 16ga. metal strap will be drawn in a direction perpendicular to the fastener until either the fastener breaks, releases from the wood, the wood deforms more than 1/4″ without releasing the fastener, or the 16ga. metal strap tears. The approximate load that the failure occurred will be documented. Each fastener type will be tested 5 times.
Now, is this a fair test of how well an individual fastener handles a shear load from a metal hanger? If not, how would you change what was laid out above to make the test better?
—EDIT—
This will be the first test of the new series:
Driven Nail Pullout:
Purpose of the test is to determine if the method of driving an individual nail has any bearing on its withdrawal capacity.
Test Materials:
The standard nail used on this test will be the 16d Duplex nail, so chosen because of its unique ability to be grasped for withdrawal without damaging the nail or wood after the nail has been fully driven. The wood used in the test will be Green Douglas Fir, the size will be at least 4×4. Measured moisture content and weight of samples before testing will be recorded.
Variables to be tested:
Nails driven with hammer in 3-4 blows driven by experienced carpenter
Nails with field flattened points driven with hammer by experienced carpenter
Nails driven with palm nailer
Nails driven with hammer by inexperienced carpenter
Nails driven by palm nailer into prebored pilot holes (sizes to be specified)
Test Apparatus:
Most engineering test machines are designed to provide maximum data and minimal variation. Here we are really only looking for one bit of data: force required to withdraw a nail sample. For this, the test will use a simple claw tool, such as a hammer or pry bar to exert the pulling force. Attached to the puller will be an extension, such as a 2″ pipe over the handle or attached to the handle. The force on this machine will be applied by weight. A bucket will be attached to a set point on the lever. Water will be used to weight the bucket. Water will be gradually added to provide a gradual increase of force to the machine.
Procedure:
Sample will be secured in a vertical position, so that the nail sample exits the wood parallel to the ground. The testing lever will be placed into position so that it hangs in place with the forks of the claw secure against the top duplex head. At this point a small force is being applied to the sample. Water is gently added to the bucket by slowly pouring in water from another bucket. The test will conclude when the sample nail has been withdrawn at least 1.5″.
Sampling:
In accordance with recommendations in ASTM D1761-88 Section 7, there will be 10 tests per variable
—END EDIT—
If you want to read up on the history of this, here are the links to my two previous tests posts.
First test batch:
http://forums.taunton.com/tp-breaktime/messages?msg=59345.1
Second test – Shearwall
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=59480.1
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Edited 2/22/2006 4:39 pm ET by xxPaulCPxx
Replies
So.....just low on material money? I really haven't ever thought about it but haven't some of the fastener companies done shear tests that you can just compare data? Just a thought to save you some time. DanT
I've not been able to find any actual test done like this with a variety of fasteners. While Simpson and USP do have screw ratings for some of there products, it's not exactly clear what kind of screws were used. While they say "use a B18.6.1 Wood screw", good luck finding a box of screws that says that on the side!
I have been able to get shear data from some manufacturers, but it doesn't tell the whole story. Their tests are done in a metal vice, not embedded in wood with a softer metal bracket.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Paul, you'd probably be able to order that particular screw from Simpson.
blue
Oddly enough - no! They only make two screws, the 1/4" lag and the #8 wafer head - and neither one of those has a shank of .164 as they call for in their specs.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Paul you go the ASTM web site ansee if they have the tests they use detailed.
Mr. T.
There's a steering-wheel in me pants and it's driving me nuts!!!
You can read up on the test criteria, but they charge you for that.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Paul, explain the reasoning behind the number of hammer blows necessary to drive the nails tight to the hanger and why you would pilot hole a nail?
A great place for Information, Comraderie, and a sucker punch.
Remodeling Contractor just outside the Glass City.
Quittin' Time
To everyone who questions why I am specifying the number of blows to seat the nail being tested:
From:
MikeSmith <!----><!---->
6/20/2005 5:31 pm
To:
xxPaulCPxx <!----><!---->
(36 of 102)
59480.36 in reply to 59480.1
paul.... i watched your video...interesting..
you nail like a girl..your test would be uch more palatible if you drove the nails with 3 whacks instead of twenty taps
From:
Piffin <!----><!---->
6/20/2005 6:14 pm
To:
MikeSmith <!----><!---->
(37 of 102)
gawd, that much extrra vibration and distorttion of the wood from all that tapping away would ruin any connection friction, even with ring shanks! to make a valid comparison, he'd have to run the screw in and out twenty times in the same hole to know anything.
59480.37 in reply to 59480.36
Basicly part of the test would try to determine if the number of blows actualy does make a difference in how well a nail holds.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Any deck or floor is going to see more vibration over the course of it's use than it would if you tapped it 100 times to drive it home. Seems to me, that it's more important to drive the nails acurately than quickly. A mis-hit is going to weaken the holding power of the fastener much more if the force of the blow is greater.
BTW, I'm not saying that you should tappy tap it home, just that the "vibration" thing doesn't make sense. The amplitude of the vibration would be greater the more powerful the force being used - which would serve to loosen the grip more than little taps which would result in far less side to side motion as the nail is going home.
Edited 2/15/2006 7:58 pm ET by Soultrain
I'm on board with that myself, and so are some others. Instead of getting into a pissing match of who's right I'd rather to a repeatable experiment to verify one claim or the other.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
I am not that interested in the experiment or which fastener is superior. I didn't read your previous thread either. What did impress me is that you can maintain your focus and keep writing objectively even after responses like Mike Smith's and Piffins.Good luck with the experiment and I agree with who ever it was that encouraged you to ignore the grumpy pessimists.Karl
Thank you, Karl!Rebuilding my home in Cypress, CA
Also a CRX fanatic!
karl... you have no sense of history..
paul and i are practically sheepherders..
and , further more, i'm a son-of-the-golden-west.. just the way we californians talk to one another
Mike Smith Rhode Island : Design / Build / Repair / Restore
Mike, you are right I don't have the whole picture, I still haven't read his original thread aside from excerpts of yours and piffins posts.If I remember correctly you were either born or spent some early years here in Santa Cruz where I live.Sorry if I responded to your words out of context. I just hated to read what appeared to be discouragement for an inquiring mind.karl
paul.. inquiring mind ?
well, yes , that's one viewpoint.. i think it's really that he never learned how to hit a nail with a hammer.. so he started using screws..
now he wants to justify their use as an alternative to nails..
more power to him... but please... how does this advance the trade of homebuilding ?Mike Smith Rhode Island : Design / Build / Repair / Restore
It takes your mind off less pressing issues, like making payroll, dealing with crumby customers, working in the freakin cold. ;)
Besides that Mike, I really just want to know how right you are. It not just enought to know you are right, I want to understand as many aspects as possibe why you are right! Aren't you just dying for me to know how right you are too!?!Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Hey Paul----if this sort of experiment is what you do for relaxation then I say let'er rip---the heck with the neasayers...Do me one favor if you go ahead with the experiment--Put one toghether with Piffin screws and lets see how they really do--Come'on you know you want to--I'll even send you some--Heck I'll even pick out the drywall compound out of the head just to verify they really are DW screws.Someday when I see a box of Hanger Screws next to the hangers I use them--till then Nails it is---even if it takes 15 wacks--:-)Mike" I reject your reality and substitute my own"
Adam Savage---Mythbusters
Actually that is one of the things I wanted to do, mostly for giggles myself.
My first set of tests were for fasteners I had already planned on using - I had used them before and loved them. But obviously there are ALOT of other screws out there, as well as alot of other nails. What I did before was far from complete. Besides drywall screws, there are also the #10 and #12 self drilling screws. There are concrete screws too. I never did test a 3" smooth coated 10D nail, nor a galvy. If it fits in the hole - load it 'till it breaks!
I'm interested in that hydraulic jack WITH the pressure guage on it. That would make things much easier.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
You know you could finish that bike and go for a ride with all that extra energy--I took down a ceiling in a kitchen once with the Master b-room directly above--After I got the insulation down guess what I found--the entire bedroom floor was hanging on joist hangers between the exterior wall and the stair case and wanna guess what kinda fasterers were filling the holes?Drywall nails---Can you believe it--Thank God they didn't have a water bed---Seriously could have killed someone--I stood on the ladder and stared in disbelief--Didn' t have to sell that change order to hard---Still amazes me how much abuse a house will take and stay standing--till a tornado, hurricane, earthquake and the whole thing collapes like a house of cards.Still scares me to think about it--Mike" I reject your reality and substitute my own"
Adam Savage---Mythbusters
paul... a big part of the problem is verification in the field and liability after the fact
as a Contractor i own the job.. and i own the liability.. so i want to move that liability to someone else
the town i build in has a building code to protect their citizens and also to avoid liability..
so.. a bunch of people with various backgrounds devolve a model building code..
and they want to include processses, techniques and materials that willstand real world tests , and that can be verified by inspection
most of what we do in frame construction is based on sound engineering and repetition..
eg: joists @ 16" oc... not one at 17" and one @ 15".. and the failure on one joist doesn't mean the failure of the system... so nailing schedules and nailing patterns have developed since North America developed light frame construction
the nail can be installed with a hammer..very efficient.. it has shear strength, and withdrawl resistance, you can see it
screws area a different animal.. they have their place.. but their place is not in assembling frames in the field.. perhaps in a manufctured enviornment, where everything could be inspected and verified.. but not out in the field where every tom, dick , and harry can and does substitute one screw for another..
which brings us back to the liability.. Simpson allows screws.. in fact they insist on them in some applications .. but their SDS screw is coded and marked on the head so anyone can tell if the correct screw was used ..
their hanger nails are coded on the head also.. again , liability and verification
they don't want failures being blamed on them when someone substitutes with the wrong fastener
anyways.. have fun with your experiment... but i will not use screws for metal connectors unless they are specified by the connector mfr.Mike Smith Rhode Island : Design / Build / Repair / Restore
I am cross posting this info, as it also pertains to this discussion:
http://www.strongtie.com/productuse/faq-general.html
The other one was USP Connectors:http://www.uspconnectors.com/nails.shtml
OPTIONAL NAILS FOR FACE MOUNT HANGERS AND STRAIGHT STRAPS LOAD TABLE
Catalog Nail
Replacement Fastener1
Allowable Load Adjustment Factor
DF-L
SP
S-P-F
LVL
16d common
8d common
0.70
0.75
0.60
0.70
16d common
10d Box
0.67
0.72
0.58
0.67
16d common
10d common
0.83
0.91
0.72
0.83
16d common
12d common
0.83
0.91
0.72
0.83
16d common
10d x 1-1/2
0.81
0.88
0.70
0.81
16d common
10d Sinker
0.59
0.64
0.51
0.59
16d common
16d Box
0.74
0.80
0.64
0.74
16d common
16d Sinker
0.83
0.91
0.72
0.83
16d common
16d x 2-1/2
1.00
1.00
0.86
1.00
16d common
No. 8 x 1-1/2 Wood Screw
0.60
0.66
0.52
0.60
10d common
8d Box
0.63
0.68
0.54
0.63
10d common
10d Sinker
0.70
0.77
0.61
0.70
10d common
8d common
0.83
0.90
0.72
0.83
10d common
10d Box
0.80
0.87
0.70
0.80
10d common
8d x 1-1/4
0.64
0.69
0.55
0.64
10d common
No. 8 x 1-1/2 Wood Screw
0.72
0.79
0.63
0.72
10d common
10d x 1-1/2
0.97
1.00
0.84
0.97
10d common
16d Sinker
1.00
1.00
0.86
1.00
10d common
No. 8 x 1-1/2 Wood Screw
0.72
0.79
0.63
0.72
12d common
10d x 1-1/2
0.97
1.00
0.84
0.97
12d common
16d Sinker
1.00
1.00
0.86
1.00
12d common
No. 8 x 1-1/2 Wood Screw
0.72
0.79
0.63
0.72
8d common
8d Box
0.75
0.81
0.65
0.75
8d common
8d x 1-1/4
0.76
0.83
0.66
0.76
8d common
No. 8 x 1-1/2 Wood Screw
0.86
0.95
0.75
0.86
8d x 1-1/2
8d x 1-1/4
0.76
0.83
0.66
0.76
8d x 1-1/2
No. 8 x 1-1/2 Wood Screw
0.86
0.95
0.75
0.86
10d x 1-1/2
8d x 1-1/2
0.86
0.93
0.74
0.86
10d x 1-1/2
No. 8 x 1-1/2 Wood Screw
0.74
0.81
0.64
0.74
1) No. 8 x 1-1/2 Wood Screw has a shank diameter of 0.164" and shall conform to ANSI/ASME Standard B18.6.1-1981.How to Use:The base value is the catalog listed nail in Douglas Fir-Larch and the adjustment factor is the multiplier for the applicable replacement nail and wood combination.• Adjustment factors may vary with some custom hangers or steel thicker than 10 gauge. Contact USP for exceptions.• Roofing nails shall not be substituted for any nail size or type.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Edited 2/16/2006 7:23 pm ET by xxPaulCPxx
OK, I just got the ANSI/ASME B18.6.1 standard ($35 from IHS Global), and here is what I found:
The B18.6.1 standard defines the the size, thread count, and head recess specifications. Basicly it is the standard by which you can call a particular screw a #8 screw. The sizes are different for cut thread (like the old fashined wood screws) and cold rolled threads (like deck screws).
You know what the odd thing is? You would expect "No. 8 x 1-1/2 Wood Screw has a shank diameter of 0.164" to have a shank diameter of 0.164... but no: The shank range for cut thread is 0.168 to 0.157, while the range for rolled thread is .136 to .125. According to the ANSI standard, they are equivalent screws!
But here is the real kicker: Material
"Wood screws shall be supplied in steel, corrosion resistant steel, brass, alluminumn alloy, or other material designated by the purchaser... Screws may be heat treated at the option of the purchaser or the manufacturer to develop adequate torsional strength for the intended application."
So those "No. 8 x 1-1/2 Wood Screw has a shank diameter of 0.164" and shall conform to ANSI/ASME Standard B18.6.1-1981." fasteners can be made of Hardened Steel, soft steel, brass, SS, aluminum, beeswax, carved carrots... there is nothing there in the standard preventing that! As long as those carved carrots fit the right dimensions, they are an ANSI type fastener!
The funny thing is that USP (and Simpson too, if you dig around their documents) really go out on a limb by NOT being more specific about what screw material they allow. So that .86 load multiplier for the screw compared to the hanger nail - that screw could be made of really anything.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
I have now the ASTM D1761-88 "Standard Test Methods for Materials in Wood" (cost me $40). Using the methods outlined in this standard, I'm looking at the following specific test:
Driven Nail Pullout:
Purpose of the test is to determine if the method of driving an individual nail has any bearing on its withdrawal capacity.
Test Materials: The standard nail used on this test will be the 16d Duplex nail, so chosen because of its unique ability to be grasped for withdrawal without damaging the nail or wood after the nail has been fully driven. The wood used in the test will be Green Douglas Fir, the size will be at least 4x4. Measured moisture content and weight of samples before testing will be recorded.
Variables to be tested: Nails driven with hammer in 3-4 blows driven by experienced carpenter Nails with field flattened points driven with hammer by experienced carpenterNails driven with palm nailerNails driven with hammer by inexperienced carpenterNails driven by palm nailer into prebored pilot holes (sizes to be specified)
Test Apparatus:Most engineering test machines are designed to provide maximum data and minimal variation. Here we are really only looking for one bit of data: force required to withdraw a nail sample. For this, the test will use a simple claw tool, such as a hammer or pry bar to exert the pulling force. Attached to the puller will be an extension, such as a 2" pipe over the handle or attached to the handle. The force on this machine will be applied by weight. A bucket will be attached to a set point on the lever. Water will be used to weight the bucket. Water will be gradually added to provide a gradual increase of force to the machine.
Procedure:Sample will be secured in a vertical position, so that the nail sample exits the wood parallel to the ground. The testing lever will be placed into position so that it hangs in place with the forks of the claw secure against the top duplex head. At this point a small force is being applied to the sample. Water is gently added to the bucket by slowly pouring in water from another bucket. The test will conclude when the sample nail has been withdrawn at least 1/4".
Sampling:In accordance with recommendations in ASTM D1761-88 Section 7, there will be 10 tests per variable
So how does this strike you as a test of the various claims of how a nail holds? I based it off the same test they do in the labs, but use tools of the field instead of precision presses. It's also easy to verify any results as everyone has access to a 4x4, Duplex nail, hammer, pipe, and bucket for water. Based on this setup, would you be satisfied the results would provide an accurate picture of how the method of driving an individual nail affects its withdrawal capacity?
Rebuilding my home in Cypress, CA
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Edited 2/18/2006 2:47 pm ET by xxPaulCPxx
"Nails driven with hammer in 3-4 blows driven by experienced carpenter"Paul,I asked you once to explain that to me and you didn't. Can you please explain what the hell your talking about the amount of blows and an experienced carpenter has to do with nailing a joist hanger. Any idiot can nail a joist hanger. I don't get this at all.Joe Carola
Sorry, I had replied to someone else about this and I thought you might have caught it then.
Take a look at what Piffen wrote a couple of posts up:
Both he and Mike have said repeatedly that the holding power of a nail is directly related to how it is driven. This came up by Mike and Piffen as a way to explain how screws could miraculously hold more than nails in my first test series. No, it doesn't make sense to lots of people, but Mike and Piffen are two experienced proffesionals and they are in love with this idea. If testing shows they're right, well then we all learn something potentially usefull. If testing shows they are not... well, that remains to be seen.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Any idiot can nail a joist hanger. I don't get this at all.
*chuckle*
... .
<faint sound of experienced carpenter hitting a period 3-4 times>
*smirk*
Wasn't this on an episode of the Simpsons?
Beer was created so hung over carpenters need 3-4 blows to sink a hanger nail.
Edited 2/18/2006 9:39 pm ET by IdahoDon
"Wasn't this on an episode of the Simpsons?"It's true; any idiot can nail a joist hanger. Even Bart Simpson. I don't get this test with pre-drilling holes for nails or screws. How many hits with the hammer it takes sink a nail? What does the amount and of swings have to do with anything? There’s no skill or technique involved with nailing a joist hanger.What about the hanger nail guns? I haven't read this whole thread nor will I but I use my guns all the time for hangers. Don't you think maybe Simpson or Engineers did these test at there facilities already and that's why we use nails and Simpson shows nails on their website and Paul's tests mean nothing.I think this whole thing started because someone said that Paul doesn’t know how to use a hammer and thought that using screws was easier or stronger. Who the hell would use screws for joists hangers anyway? I certainly would never even think about it unless I got a set of plans that said that I had too. You can’t beat the nail gun and before that was the palm nailer and before that was my hammer with my massive Popeye Framers forearm and if my hammer broke I nailed them in with my fist or sometimes my third leg if I had a few the night before..........;-)Joe Carola
Edited 2/20/2006 6:13 pm ET by Framer
my hammer with my massive Popeye Framers forearm and if my hammer broke I nailed them in with my fist or sometimes my third leg if I had a few the night before..........;-)
LOL.View Image
Interesting test. Unfortunately, grain, knots, heartwood, sapwood, could drastically scew the results of identical nails, only an inch apart.
Yep. That's why you use at least 10 samples to achieve a 95% accuracy of results.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Sorry. 10 samples would give you +/_ 10% accuracy.
5000 samples an you may have some interesting data on nail pulling.
Best of Luck.
Red
Edited 2/20/2006 3:25 pm by RedRobertson
Well, you read the ASTM D1761 - 88 (Reapproved 2000) document and tell me how I read it wrong. By my reading, in Section 7.2, under Note 2, they say "The present recomendation is to make at least 10 replications for each variable as a minimum requirement". True, I may have misread how they achieved their 95% confidence, but I am going by their recomendations.
After you read the document, I'd love to hear how you would improve upon the experiment.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
As has been noted here, shear strength not pullout is how a load reacts to a joist hanger.
Your original post asked for a test.
Build a 8'-0" square wood frame. Install several joists on hangers with a variety of nails, screws, whatever you want to test. set your frame on concrete blocks so the top is 19" off the ground. Take an 8 lb sledgehammer and attack a joist untill the hanger fails.
If you are not able to accurately swing a sledgehammer, mount a 100 lb steel block on a pulley and drop onto the joist from a controlled distance until the hanger fails.
Red
Paul,Red has an interesting proposition in the previous post. I don't think his test mimics in-service conditions very closely, but it does offer a different type of stress than the steady pressure you are exerting in your test protocol. His test would definitely cause Piffin screws to snap off, but I'll guess that the Deckmate screws might stand up pretty well.Red's test idea mimics the stresses subjected to a building being dismantled by gorilla laborers. It may also duplicate some of the conditions found during a seismic event, and a hurricane.I think your tests will be very interesting to hear the results of, even if they change no one's fixed opinions. There are remodel situations that demand screwing hangers to protect old plaster with irreplacable historic wallpaper, for example. It would be nice for Simpson to offer screws that are rated as a direct replacement for 10 commons and for 10 shorts. That covers the vast majority of applications, and it seems that this would not be hard for them to do. Perhaps your initiative will hasten the day that this occurs. Test on!Bill
My wife (exwife) would not allow me to have car parts or motorcyles in the house. She was always re-arranging the furniture. I think I would have been in a lot of trouble if I had engine parts in the kitchen and bathroom..++++++++++++++++
-Do the thing you fear and the death of fear is certain-
I saw the video the first time.
Put down the drill and try hitting the nail with your purse.
This place is awesome. Out of pure curiosity this test interests me. But from a practical standpoint it is a GIGANTIC waste of time. But it's your time and not mine so I guess I shouldn't care. But I still really don't understand it.
So my curiosity grows.........Why would you even want to use screws on a joist hanger? First off, hanger nails are about the easiest nails you could ever have to drive. You pretty much can't screw it up. There's a hole where the nail goes! And they're short. It takes real talent to bend one. What's easier than that? You also mentioned that you own a palm nailer..... now that's gonna get you into a tighter spot than a cordless drill can. Or better yet try a peashooter..... those will get a nail into spots that nothing else can.... but you do need to swing a hammer at it. I've owned palm nailers, but I find that swinging a hammer is actually faster. Even faster than that is a positive placement nail gun. But I can understand that not everyone is going to own one of those. Screws seem to me to be at the bottom of the list for both speed and ease.
So what's this really all about Paul? Is this because you really feel screws are a better way to frame? Or can you really not swing a hammer at all? Or do you just need to be right? I really don't believe that it's pure curiosity on your part. Curiosity would motivate someone to view the results of such a test, but I really doubt it would motivate someone to actually perform such a test. So whats the real motivation here dude? So while we're being curious here, humor my curiosity.View Image
try hitting the nail with your purse.
LOL.My milkshake brings all the boys to the yard
Brian,Thank back to your formative years. maybe your mother read you a story or you saw sonmething on the tube or on the street that profoundly impacted you, your thinking, and who you were to become and what you would do or how you would react to certain situations in life.
It's who you are now...CRXpaul's mother probably read him the story of David and Goliath while cradling his head to her bussom and stroking his beautiful hands. Right then and there, the seeds were planted. He knew deep down that someday, somewhere, somehow, he too would topple a foe who was larger than himself....thus he puts up his screws against a fistfull of nails in his quest for the glory that goes with a well-hung joist.I haven't made up my mind whether to admnire his steadfast cockiness or to write off another fool, but you have to admit that he is an interesting character study.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
he puts up his screws against a fistfull of nails in his quest for the glory that goes with a well-hung joist.
I'm a well-hung joist myself. Sorry, couldn't resist. Yeah, Paul is a strange duck. Not quite sure what's making him tick on this one. Hopefully he answers and explains a bit more about his quest. Gotta hand it to him though.......pitbull determined, he is.View Image
I like pitbulls - they're just misunderstood
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Put down the drill and try hitting the nail with your purse. Yep, that is a funny line. I laughed my #### off too when I originally read that a few months back.
OK: Why Am I Doing This?
In case it interests anyone on this matter, I'll give my whole technical history: I got my first tool kit when I was about 4 or 5, the same Christmas I also got my first electricity experiment kit (batteries, lights, switches, buzzers). Both were handmade by a family friend. Growing up, I watched and tried to help my Dad in the pits while he was racing Formula 1 snowmobiles in the 70's-80's. It was fascinating watching him come up with new intake port designs and new track stud patterns. I sometimes got to restud the tracks with the air impact gun.
I entered college on an acting scholarship, but my second ambitions were Automotive design and Physics. I didn't take the wussy Atmospheric Science class that everyone else took for the easy A, I took the Chemistry and the Physics classes for people going into those fields. The only thing I was really good at in those classes was setting up and executing the experiments, or doing special projects using lessons learned in the class (hands on type projects).
In the Theatre department, my paying job was in set construction. I had worked for free for a few months as a volunteer, then they offered me a job. There I got to play with the fun tools like the table saw, radial arm saw, bandsaw, welders, etc. Not a nail to be found in the place, unless it was used in the desks the college sources in the a store. Everything was screwed, bolted, or glued and stapled. And the pieces I built in the day were the same ones I was rehearsing and later performing on at night. Every show used some new and exotic material, just to test the graduate students. After the last show I helped to completely disassemble the whole thing... those pieces, be they platforms or even just raw studs would then be used on the next show. The stuff we built rarely broke (and if it did, it was likely I broke it on stage. I was notorious for tearing up sets accidentally), it usually just wore out from constant wear.
So there you have it. A background with power tools, experimentation, weirdo materials, and screws.
Really, I've been using screws for years before I came here. The bad rap that people give them goes completely against what I have seen and experienced. Also, since I am a DIY, I feel I have to stand up for all those who do not swing a hammer profesionally. I think it is absurd that someone needs to practice driving nails for 40 hours until they can attach ONE joist hanger. If there is a different way of doing it, you bet I'm going to try to find out what it is! Not all of us have to mount 400 LTP4's this week, plus 60 HUS28 hangers and 100 feet of strap... some of us just want to connect two pieces of wood together. Some of you pound 1000 nails in a day, some of us pound 1000 in a lifetime maybe. I can't believe that everyone has to use exactly the same technique - there has to be another way. You don't have to spend a month as a barista at Starbucks to make a decent cup of coffee.
The last part of it is really just me. When ever someone says to me "We've done it this way for 10 - 20 - 50 - 100 - 500 - 2000 - 5000 years..." it just makes me deeply suspicious. Doing it the same way as eveyone else never won a race, and it never wowed anyone in the audience. Whenever I'm presented with that statement, my first instinct is "Why Not..." and explore that as far as I can. Lots of interesting things down those rabbit holes.
I know there are ways of doing things that are done every day, day after day, by thousands of knowledgable and skilled proffesionals. My exploring a different way of doing it should not be construed as a personal insult to anyone. I've learned alot about this whole issue, even from people arguing against what I think to be the case. I respect all of your input, except when you come after me like you just fell off your bar stool.
To answer your question about curiosity... well, back when I was presented with the opinions that screws only break and that they couldn't possibly take the load that a nail could in a hanger, I decided I should find out if it was true or not. Web seaches found nothing, and really - do YOU ever remember someone doing this? Even if the hanger companies did their own tests, they've never published exactly what materials they've used on those tests. No one else has the answers I was looking for, so I decided to perform some simple experiments and find out for myself. What my experiments showed, and showed CLEARLY, was so different from conventional wisdom on the matter. It's not that I think I'm right, I've actually got experimental data that supports it. Some people have questioned the methods used in those tests, so I am more than willing to run them again using better methods. This is great fun for me! It really gets me thinking, and exploring.
Curiosity would motivate someone to view the results of such a test, but I really doubt it would motivate someone to actually perform such a test. See, that doesn't make sense to me. If someone told me that the world didn't work the way I thought it did, and I only had to put four pieces together to prove myself right or not, I'd do it. As a matter of fact, I did it! 5 minutes on a lunch break with scrap material is all it takes to prove me right or wrong. I'm astounded.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
This is such an absurb thread I hardly understand why I have read it or feel the need to reply.
I think this is just a matter of you viewing yourself as David and the pro's on the board as Goliath. You asked for an opinion, didn't like or agree with the answer, couldn't sway anyone to your point of view, couldn't find information to back your view up so now feel the need to prove your point.
But the bottom line is pro's do this for a living. They need a tried and true method that will work each and every time and therefore if it would fail has limited liability as it is a proven and accepted method. You proving it in your garage will prove it to no one else but you.
No pro could take your information and use it even if they wanted to because if it failed and they were sued what defense would they have? Paul showed us it would work in his garage and he posted pictures on the web and everything? And frankly if you haven't been here for a lengthy period of time, shown your work consistantly, given advice or opinions that made sense who would believe you. This is the internet. You could make it all up and who would know?
But as many have mentioned it is a free country so you are free to waste your time as you wish. But many here need to make a living so won't take the time to prove any of the information for it simply doesnt' make sense to skip making money to prove a point that doesn't matter. But hey, have at it. DanT
Just checking with you - does the nail withdrawl experiment look OK by you? I'd like to use it to verify what you've said. Piffin said it looked OK by him, but I haven't heard from you.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
paul... the test looks fine with one exception...
you say it will continue until the nail is withdrawn 1/4" but my expreience is different
sometimes it's easy to pull the nail for the first 1/2" but next to impossible to pull the next 2"... on a 3 1/2" nail ( 16d duplex) i'd want to see 1 1/2" withdrawl
and of course , as in my last post, none of this will be helpful unless it becomes code approvedMike Smith Rhode Island : Design / Build / Repair / Restore
I went to college in the 70's to be a shop teacher. One chapt in a text book was called "fasteners". Information was provided about the various types of nails, screws, nuts & bolts, etc.Info was provided regarding the holding strength of screws and fine thread vs coarse thread, etc. I think I saw something recently that coarse thread screws are recommended for attaching drywall to the studs.
Is this correct?Something I thought was interesting was the procedure to attach a 2 X 4 stud to a top or bottom plate. If I remeber correctly the text book stated the strongest method was to toenail the 2 X 4 to the plate rather than nailing through the plate and into the end grain of the 2 X 4. If this is wrong please correct me..++++++++++++++++
-Do the thing you fear and the death of fear is certain-
True, whether stud to plate or joist to rim, the toenailed connection is always stronger than end driven
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Paul: the straight withdrawl resistance of a nail makes absolutely no difference. No joint worth anything uses the (poor) straight withdrawl resistance of nails to support it.
The guys were just teasing you about your inability to put some power into your swing. When it comes to common nails, I doubt it matters whether you drive the nail in with one blow with a pneumatic nailer, three blows with a hammer or a hundred blows with a palm nailer. Spiral or ring shank nails or fastener nails with hot melt glue on them are another matter. But regardless- who rightly cares about what affects the total withdrawl resistance of a fastener? It's not the withdrawl resistance that's of key importance here- if the nails are withdrawing, the fastening system has already "failed" long before that point. Total separation of one member from another isn't a sufficient definition of failure for a structural joint- it's merely an indication of how hard it will be to demolish the thing later.
I'm anxious to see what you come up with in your tests, but the tests of how the fasteners resist shear when used in a fastening plate is what interests me. How hard it is to pull the nail out with the claw of the hammer isn't something I care about at all.
As to the precision of your results and the confidence interval of your tests, I can help you with that if you wish. 10 samples of each assembly are probably enough if they're independent- randomized over the other variables like the piece-to-piece variability of the wood etc.
Paul, don't let those naysayers talk you out of doing your experimentation. I want to know the results and when they're in I'm going to print them out and save them. Then one day, when I'm in a weird spot and have to use a screw instead of a nail, and Piffin shows up as the inspector and knocks the job down, I'll pull out my "proof" and show him why screwing is better than nailing.
blue
You big tease, you!
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I run into some situations where I have to use screws and it's really not an option to use nails.Several years ago I installed a garage door, the rails, and opener. I needed to attach some of these components on the garage wall but the garage wall was also the adjoinining wall for the living room.I did not want to drive heavy 16 d nails into the garage wall as the other side was the living room and finished in sheetrock, painted, pictures hanging on the wall, etc. I worried about hammering on the wall and jarring the drywall and maybe popping loose some of the mud over the nails. I worried about the sheetrock joints cracking etc as the result of my hammering.I used the large screws and didn't do any pounding on the walls. Maybe I was over cautious I don't know..++++++++++++++++
-Do the thing you fear and the death of fear is certain-
garage doors come with lag screws to install. I have never used a nail to install one. That is a proper and intended use of a fastener. wEare talking about replacing nails with screws in a situation where nails are the design tested fastener. Since screws are recognized as having less shear strength than nails the OP has the burden of proof to demonstrat his theory that screws are adequate for his purpose.Your installation was originnally desgn tested with the screws in mind, and an adequate number included witht he rail mounting hardware.But personally, I'm curious why you wanted an overhead door going from the garage to your living room. My brother used to have his Triumph in the LR and the engine in the bath tub with the carburator on the kitchen table ...he might have appreciated your idea;)
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I thought they were just teasing too awhile back, but no they really are serious about this. They really believe that the poor results that nails had in my tests were due to my poor pounding technique. If that is true, then that does undermine the whole test series I originally did. For that reason I am very interested in verifying that claim.
But this is only the first test of a new series. I also intend to test a whole range of other fasteners, screws primarily. I'd like to see if there is a way to distinguish the "good" screws from the "bad", if there is such a thing. It would also be nice to have a better idea of what the range is out there. The first test was a validation of the fasterns I knew and trusted, this second one I intend to find the ones I don't trust.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Paul,
I've been poking my head in here occassionally to see what all the hubbub is about. I find your experiment interesting and am having a hard time understanding why some folks are taking such offense at it... maybe you've tinkled in their wheaties in some way that I've not witnessed.
One think that sticks out to me is your idea to predrill holes for the nail application. This doesn't seem to jive with what I would consider a proper experiement as it would be highly uncommon to see predrilling performed for nails in any real-world application.
I've seen the point made that sheer strength should be the direction of testing, not pullout resistance and I agree. You may wish to test both but I believe that pullout strength is not a primary component of the final integrity of a joist hanger installation, sheer strength is.
In a quick mental assessment, I think that I see an obvious difference in the potential sheer strength of nail vs screw. The continuous shank of a nail is typically of greater diameter than a screw. The nail is also more maleable. These two conditions would contribute to the shear strentghs of each. I also know that various screw types are composed of distinctly diffenrt materials bearing unique characteristics where framing nails are regularly composed of typical materials.
The difference between stupidity and genius is that genius has its limits. -Albert Einstein
http://www.peteforgovernor.com
I've updated the first post so that it includes the first test that was agreed on... I'll update that first post latter on as it seems lots of people only read the first page then post, without catching up on the whole thread where the meat of the discussion takes place. You'll find out about the predrilling on the 2nd page, I think. I think you are about the 5th person who has asked about that now. It is important to do the nail test specificly to see if there are any variables that can be introduced by the person driving the nails that may affect the nails holding performance. If I drive the nails in such a way that they do NOT hold as they should, then my test results are bunk.
This is getting a little ahead of ourselves a little, since we haven't come up with an agreed on test for the second phase which will examine fasteners in a shear plate connection. But I can tell you what I consistently observed in my first tests - follow the links in the first post to see pictures of what I describe:
View Image
Here is a drawing of what happens to nails and screws when they are subjected to extream load from a shear plate connector in wood. Assume the grain is crossways, so in the pictures you are looking at the end grain with the fastener in the side of the grain.
What I observed was that as the load increased, the fastner would deform and start crushing the grains of wood around the mouth of the hole. Gradually, this crushing changed the borehole made by the fastener from a cylender to a rounded ramp. Due to the softer metal of the nails, this rounding was very pronounced. This rounded ramp changed the force exerted on the fasteners too. Instead of a straight shear, it was now shear PLUS a great deal of withdrawl force. This withdrawl force was being resisted by nails with less contact with wood now than when they were driven before the load was applied.
The screws did deform slightly, but due to the stiffness of the harder metal they transferred more of the load throughout fastener, levering slightly instead of bending. Even when some of the 3.5 inch Deckmates did create that same rounded ramp at the mouth of the hole, they still held fast in the wood. When bent over at least 45 degrees, bent over at least 1/4" off the center due to the load, the actually started tearing through the softer metal of the 16ga Simpson strap. I can't say this will always happen, I'm just stating what I observed, repeatedly.
Straight shear values dont tell the whole story, nor does metal cross section, metal composition, hardness, etc. There are a whole host of factors at play here. I wouldn't have know it had I not done the tests and seen it with my own eyes. Here are a side by side of nails and screws subjected to the same amount of force, in this case holding OSB to douglass fir:
View Image
The nails rounded in the hole and let go, the screws stayed intact.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
In your picture there..... what kind of screws are those? What are they specified for? I'm curious because screws that take that sort of beating obviously aren't run of the mill deckers or wood screws, right?
(It's not a trap. I'm truly just curious about what kind of screws those are)
I'm sorry if I'm still confused, but one more time.....why is it that you use screws? It's just easier for you because that's what you're used to?View Image
Those particular screws are the colated ones made by Senco. They are 2" long and are code accepted replacements for 8d nails in shearwall. Before anyone flys off the handle and screams "NO THEY AREN'T", we've had this talk before, please take a moment and look them up if you don't believe me. Senco has the docs, and it is written on the side of every tub of these screws. Run of the mill deck screws? I guess - they were made for screwing down decking. They have longer ones too, also code accepted.
BTW, I used that pic because it was just handy. I got the same results from the McFeelys and Phillips Deckmate Square Driv in metal hangers.
Why do I like using screws? Consistent results, they don't damage the materials if I goof up and have to disassemble, I don't have to destroy a piece to move it later on, they pull the pieces tight, they can be re-used to a certain extent, if you are carefull you can reuse the original hole you sent a screw down too, I can put them in all sorts of awkward angles with the tools I have, I've never hurt myself or someone else driving a screw, I've never had a screw shoot from my driver due to equipment malfunction... that's all I can think of off the top of my head right now. Note I said nothing about speed or efficiency. For a DIY, only being able to drive 10 or 100 screws in the time it takes a framer with a gun to drive 1000 nails isn't really that much of a selling point for some projects.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Screws are great Paul. You forgot to mention that framers routinely pound them in with their hammer too. It usually takes one more whack.
blue
It's that last twist of the wrist to seat the head that throws their elbows out of whack, that's why they hate them so :)Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Just to let you all know, I've been taking a few moments here to make up the test apparatus. Working out the details so I can get reliable readings. I'll have to put a towel or something over the mouth of the bucket to keep the water from spashing out when the nail lets go.
Funny, since I'm not pounding at an odd angle with the way the sample wood is set up, I actually can sink a 16d duplex in 4 whacks! At least in the trial piece (not running real tests yet).Rebuilding my home in Cypress, CA
Also a CRX fanatic!
'I actually can sink a 16d duplex in 4 whacks! "WhaddidIsay?!by time you finish this test, you'll be a better nailist and loving nails more than ever!;)
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> .... if you are carefull you can reuse the original hole you sent a screw down too, ....
This is SOP for piano work. You have to be able to disassemble and re-assemble things many times over the long life of a piano.
The trick is this: As you go to put the screw in, press it gently into the hole and carefully turn it counterclockwise until you feel it click into the existing threads in the wood. Then turn clockwise a couple turns to get it well started.
Someone who doesn't know this can do a huge amount of damage to a piano. Just putting the screws back in any whichway will cut new threads every time, and turn the wood to mush. Then it strips out and you have to glue in a plug and re-drill. Doing that 88 times in a row gets old in a hurry.
This little tidbit from a long-ago piano tuning class has saved me lots of grief on door hardware.
-- J.S.
That's what I do with nuts and bolts too, I didn't even think about using it with wood threads!Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Paul: I did read your old thread with interest when you first posted it. I understand how these fasteners performed in your test. But withdrawl resistance of the nails only entered into the equation once the joint had significantly deflected. Such a deflection would be considered a failure in normal service, so you'd already tested the joint to failure. Testing beyond the point at which the two fasteners have moved more than 1/2" relative to one another may be interesting but isn't all that useful for design.
What I think you need to focus on is the amount of force needed to deflect the joint (i.e. move one member relative to the other one it is fastened to) by a certain amount. You also need to disprove what many people here claim, which is that the inferior shank diameter, stress concentrations and lower ductility of screws versus nails of the same maximum diameter may lead to sudden failure of a Simpson connector-type joint where the nails are replaced by screws. The sudden failure they're supposing might happen as a result of screw heads popping off, shearing of the screw shank itself etc., things that are much less likely to occur with nails of the same gross OD. If the screwed joint sustains more load than the nailed one but is subject to even occasional sudden failure, that wouldn't be a good thing from a design perspective.
A short joist fastened with hangers at both ends to short pieces of joist material and put in a hydraulic press frame might be the best way to do this. You would block up the two ends on the bed of the press and load the centre with a load-spreading plate to reduce local failure of the joist. With a pressure gauge on the press cylinder and the area of the piston you'd know the force, and you could apply it in stages and record the separation of the joint as it occurs. You might have to through-bolt the two "headers" to the press frame to keep them from bowing inward and affecting the test.
Have you seen the simnilar testing apparatus in the JLC article regarding ledgers and instal methods for deck additions?
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That test setup is the actual ASTM method of testing joist hangers. They press the center of the "I" in one test, and they press opposite ends in the another to test the twisting forces. I will get to that, but I don't have a pressure gauge for a jack. It will have to be some kind of simple lever system. That is why I wasn't testing fully filled hangers - it's about impossible to safely create a load that will go beyond the holding capacity.
But, it will be done. That is the third round of tests.
I understand what you are saying regarding the fasteners were way past failure point. That was the point - what happens when you go WAAAAAY past normal. Well, screws took the load better than the nails, deflected less, and finally pulled out of wood (at least the 1.5") but NEVER broke. Where I could lever the 1.5" nails out of the wood with one hand (in shear direction, not withdrawl), I could STAND on the same lever and the 1.5" screws wouldn't budge.
BUT - I was using some pretty good screws. My second test round will try out a whole range of screws, good and bad, to see how they compare. I'm sure that 86% figure came from somewhere, it would be nice to know where.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Waste of time? who cares--if this is your mental release in your quest for knowledge that I am all for it--Who here doesn't have off the wall hobbies to entertain themselves---Cheetos anyone? I spend all kinds of time building stuff for myself that is almost to nice to be on a job site but I do it for my own "therepy".I, for curiousity sake, would love to hear the result--think I am gonna flash it to some inspector? No---That being said I support you in your "test" I'd even fly coach--Mike"Even a blind squirrel finds a nut once in a while" Mitremike c. 1990" I reject your reality and substitute my own"
Adam Savage---Mythbusters
"True, whether stud to plate or joist to rim, the toenailed connection is always stronger than end driven"
True enough, but since it's common practice to face nail through the plates, both carps and inspectors are willing to forego the extra holding power of toenails.
Of course, overlapping with sheating/strapping more than makes the "loss" of holding power.
Now that I read that California Paul once built props for the stage, I realize that his love for screws is based on the fact that he too "has always done it that way". ;)
Edited 2/22/2006 2:30 am ET by Pierre1
"True enough, but since it's common practice to face nail through the plates, both carps and inspectors are willing to forego the extra holding power of toenails."Not always.You are of course referring to toenails in studs to plates - and there are some places where inspectors do require a toenailed connection there, as has been reported in this forum in the past. It seems that some build toenailing while others platformframe and then toenail later after walls are staning to satisfy the local codes. But in my concern and the subject of most of this discussion over three of four threads now, is that of joists to rims or to headers and beams. And that connection is very important. 'The Simpson LUS hangers are designed to make use of toenails in conjunction to make for the most efficient and strong joint. The guide holes for the nails in that hanger make it almost impossible to not be able to drive a toenail properly, even for the new guy on the crew.As for the reason behind CRXpaul's thinking, you are probably part right, but I am impressed with his history of a love for experimentation.To be clear, I'll repeatr something I've said a few times along here, that I am not only entertained by him, but I have nothing against him personally. We could probably have great fun together in a different venue.
my attacks have been against his tenacity in recommending a method of performing this work that can cause structural failure and get people hurt.
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"I have nothing against him personally."
I really don't think anybody here does either. It's a good mix of fun and experimentation.
> If I remeber correctly the text book stated the strongest method was to toenail the 2 X 4 to the plate rather than nailing through the plate and into the end grain of the 2 X 4. If this is wrong please correct me.
Probably the important thing is that face nailing will give you more consistent results. You pretty much always get the same amount of nail into the end grain that way.
Toe nailing can be extremely weak if you don't get the nails in the right place. Someone who worked on my house used to start the nail about 3/8" from the end of the stud, at a 45 degree angle. That puts a whole lot of nail into the plate, but only grabs a tiny bit of the stud. Demoing his stuff is quite easy, the nails just break out thru the end grain.
Start too high, on the other hand, and the toenail grabs very little of the plate, and is weak in withdrawal. It may even deflect off the plate and not grab at all if it exits the end grain too close to the far surface.
Bottom line, the range from weakest to strongest toenail connection is much wider than the range for face nailing, and especially extends much farther out the low end. Which has the higher high end is debatable. My guess is that the best toenails might be better in withdrawal, and close to a wash in shear.
-- J.S.
OK, I'll use the longer length. Thanks for the input!
As for Code approval, nothing gets approved until it has been submitted for ANSI/ASTM lab tests, and nothing gets submitted there without a bunch of money being thrown at it, and a bunch of money isn't going to be thrown at something that is not yet in demand. It won't be in demand until you start asking for it Mike. And you won't start asking for it until you can see that it might just work.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Curiosity is a big part of all advancements. There are no guarantees that your curiosity can advance anything, but you can always learn something along the way. What's wrong with that?
tjhe thing about the number of times the nail is hit comes form my criticism that his method of nailing involves rattling the hammer against the head of the nail a couple of hundred times so the hole probably gets reamed and stretched to where no holding can be expected. He has yet to learn to hold a hammer and drive a nail, so his hobby is to prove that screws are just as good.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I remember hearing a programme on the radio where a phsyicist went through his garden shed and talked about the stuff inside it.From what I remember he showed that nails hold better if you drill a pilot hole about 1/64 smaller than the shank off the nail.It's got something to do with the fibres of the wood not being squashed out of the way so it can grip the whole ot the shank of the nail
Paul,
Eactly what Calvin said, explain the reasoning behind the number of hammer blows necessary to drive the nails tight to the hanger and why you would pilot hole a nail?
As to why some of the tests would use a pilot hole for the nail:
From:
Piffin <!----><!---->
Feb-13 1:07 am
To:
xxPaulCPxx <!----><!---->
(19 of 76)
69572.19 in reply to 69572.18
Drill a hole to make it easier to stick a nail in it 'cause you don't have balls enough to drive it in and it will come out easier too. That simple fact doesn't take much thinking to figure out, but you can't seem to grasp it.
From:
Taylor <!----><!---->
6/22/2005 4:50 pm
To:
JohnSprung <!----><!---->
(57 of 102)
59480.57 in reply to 59480.55
> I'm saying: "Don't pre-drill nail holes." It reduces the holding power.
The only reason to pre-drill is if the wood would split without it. A pre-drilled piece is stronger than a split one, but not as good as one that doesn't split without drilling.
From "Understanding Wood" by Bruce Hoadley, p 189:
"The fact that nails can be driven without preboring pilot holes has apparently led to the assumption that they should be driven without preboring. An unfortunate corollary seems to be that nails are therefore limited to use where they can be driven without splitting the wood or bending over. In reality, the best holding power results when nail holes are prebored [Emphasis added]. While most woodworkers accept the idea of installing woodscrews in prebored holes to prevent splitting and to maximize holding power, they seldom consider preboring nail holes."
So here we have two VERY different opinions. I'd like to find out who's idea actually hold water.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
paul.. get a life.. go out and smell the roses.. move on...
hammer blows ?
c'mon.. we use screws for four things..
mounting things like kitchen cabinets
screwing down deck boards
hanging gutters
and hanging doors if they're paint grade
as for hanger nails:
an H2.5 takes 10 nails.. i can install them in less than a minute.. with my bostich gun and the alternate nose
Mike, don't get me wrong. Screws are not the right way to frame new construction... unless you have a pretty unique design AND budget AND crew!
What I really want to do is put some of the opinions and advice I've received to a fair test. You took the time to detail exactly how to toenail in a nail through a hanger - thank you for doing that! You then said that method would create a better bond with more strength that the way I had done in my test.
Well, I would like to know if that is true. And if it is true, how MUCH stronger is it? I would really like to know that. Since you aren't going to do a break test on that for me, I guess I'll have too.
Please don't think that because I'm trying an experiment to verify your claims, I think you are a lier or a bad person! You are a wonderful man Mike, and a good and generous person. I would have sent you a valentine, but I lost your address. Maybe next year. Hope you're not still mad about that.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
I agree with the majority of the other posts...you need to find a hobby unrelated to construction to take up in your off hours. If you go to the trouble to do the tests, what's the point? Unless your authorized to engineer stamp the results and submit to building code review, you still can't use screws to mount joist hanger brakets unless you want to do them over a second time.
Paul, as pointed out, your test will not bear the imprimatur of a licensed engineer, so any conclusions will have to be accompanied by that not-insignificant caveat. But, if you're willing to spend the money and time, it should be an interesting thread. It may have limited application to real-world applications, but I applaud your curiosity. Those who think it's a waste of time can just skip over this thread.
I agree Freestate1.
Paul, don't listen to the grumps from the Norhteast. They just got hit with truckloads of snow so they aren't on their best behavior.
Do the test but don't predrill. If you need a real carpenter to drive the nails tight in less than three wacks, go to a local tract project.
I'd acutally prefer that you use an ordinary nailgun and 3" /131's like I do.
blue
related question
I have heard that the plastic on the plastic collated nails melts somewhat from the friction of the nail being driven into the wood. And that, as the plastic cools and solidifies, it acts somewhat as a glue holding the nail in.
The few times that I have had to pull out nails like this, it seemed to be true. Does anybody have any information to confirm or negate this?
Just out of curiosity, what does the number of blows required to drive the nail have to do with anything?
Hey, that would be a great thing to find out! The results of collated nails driven with a gun compared with ones that are stripped of plastic and driven conventionally... unless a single uncolated nail can be shot from a gun - that would be a better comparison.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Paul, according the the last piece of official information I read regarding the holding power of nails it is true.
I think it was Senco propaganda, I mean information that I read. They claimed that their gun nails had superior holding power over common nails, which probably is true. Not many people use common nails though. Most used some form of cement coated sinkers, which also claim to have superior holding power due to the heated up cement coating.
In any event, Senco also stated that sometime after the initial moment of nailing, the two classes of nails got closer in holding power due to shrinkage I presume.
My unscientific experience with pulling nails tells me this: when I yank a 16d cc sinker, it starts off tough and stays tough till half the nail is exposed. When I yank a gun nail (typically 3" x .131), the initial pull getting it started is slightly harder, but when the seal breaks, it finishes coming out much easier. I think this has a lot to do with the thicknesses, but once the glue bond is broken, the gun nails are much weaker. Re-nailing a pulled gun nail results in very poor holding power. Renailing a pulled cc sinker is slightly better.
The reason I know so much about renailing pulled nails is because I don't carry any hand nails anymore and when I finally need one, I usually find on laying on the deck and pick it up to use it! LOL!
blue
That is true with any coated nail
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
They are just grumpy because it's 70 here today... and yesterday... and tomorrow...
I really do want to include gun driven nails in these tests, but I have two problems:
1. I don't have a positive placement gun
2. I don't have a variety of nail sticks to load in the gun.
I really would like to know how a coated ring shank compares to a smooth coated, or how a ring galvy compares as well. I might be able to rent a gun, but buying multiple packs of 1000 nails so I can test 10 or 20 is waaay outside the budget.
If anyone wants to donate a stick though, I'd be more than willing to reimburse postage and whatever that stick might cost!
For everyone worried that I'm not an engineer, well, I am not trying to create a new engineering standard here! I am trying to verify some claims and advice I've heard. You don't need to be an engineer to perform an experiment on the materials you use every day.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Pre-drilling up to 75% of the nail diameter is allowed by code for the first piece of wood or whatever that the nail goes into, the one that gets the nail head against it. But no pre-drilling is allowed in the piece that ends up with the pointy end in it.
In real world production framing, nobody could afford the time to bother with pre-drilling any piece of wood. The metal stuff, like from Simpson, comes with all the allowable holes already there. So, for a practical test, forget drilling.
The engineering tests from which the published specs come concentrate on one item at a time, like a nail, a hanger, a piece of wood. This is because the nail companies test their nails, the hanger guys test their hangers, etc. What would be fun would be to test larger assemblies.
For that, we'd need a way of breaking strong stuff, and knowing what it took to break it. The 20 ton Norco bottle jack is available with a pressure gauge, and we could use a camcorder to record the gauge reading and go back to find the exact value at the time of failure.
I'm thinking that this could be a fun game for a fest, build the strongest possible box given a certain amount of wood and fasteners. Winner gets a sixpack, or something....
-- J.S.
Great idea John.
I'd like to have a sawhorse weight capacity contest using 1x3 bridging stock for legs and 2x4 t tops and 1/2 x 2" staples.
blue
Sounds like a good activity for TipiFest
Simple tests of real-world things are interesting so I'd be interested in hearing what you find. Although such tests are limited because wood samples will vary a great deal and there isn't much you can do about that.
Green wood simply means it's more than 19% mc, and there is a great deal of difference between fresh cut and 19%.
You'll also have a hard time finding structural screws in smaller sizes, as we've already discussed. Testing common screws is interesting, but doesn't amount to anything since they vary so much, not having to conform to a specific structural standard. You could probably find some structural screws in an aircraft supply catalog (I'll check).
I have a hydrolic ram with attachments that is sold for bending cars back into shape and have mangled many types of hangers and hanger nails with it jacking oversized rafters into place on vintage homes. After seeing first hand how much a hanger nail can hold before actual failure, it's quite impressive. It's equally impressive how gradual the failure is, with a great deal of bending and moaning.
What truely would be useful is finding a source of consistantly reliable deck screws. Cheap screws seem to be everywhere and quality is all over the board, even within the same box.
Finally, as others have said, this discussion isn't helpful for real world construction.
Beer was created so carpenters wouldn't rule the world.
Well, frankly I was amazed at how easily those hanger nails popped right out of the wood. The screws I was was using held many times the weight the nails did, and they never broke. The screws I've had consistently bad results with were Grip Rites. Take a look at the first thread link in my original post if you didn't see how those hanger nails did. Have to tried Phillips Deck Mate Square Driv screws yet? I've torn 16ga strapping plate trying to pull the #9 3.5" out of wood or shear off their head to no avail.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
I have a suggestion that may satisfy your curiosity and at the same time satisfy the need for credible tests that the "panel of judges" would accept.
Go to the nearest University Engineering Department and talk to the Professors there and see if they might be interested in some of their students setting up and running the tests. They get to learn and write a paper on the subject. The University gets to use its expensive toys. You get to find out once and for all if your ideas and conclusions have any validity. Your critics will be silenced. And the rest of us won't have to watch you kids squabbling and fighting until someone gets hurt and goes away crying.
It may take some time for them to setup, run the tests and write up the conclusions. (We can wait.) But they would be real tests that are repeatable and not something cobbled together.
When you talk to the Professors they may be able to let you access the information that industry/others have already done on the subject if they aren't interested.
It'd be great to see it realisticly and objectively done like that
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
it's amazing this thread has been up for three days without my seeing it yet...
;)
As I pointed out in your original tests, predrilling for the nails or screws will invalidate the test results.
For one thing, because nobody will do that in the field
For another, because the holding power of nails is based on the density/displacement of the wood that is displaced by the nail going in, so if you remove the wood instead of displacing it, there is not nearly the same friction bearing on the surfaces of the sunken nail. It has to be driven, the same way it is in real life.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Take a deep breath and read the test again I just proposed to Mike. I clearly state that I will do a test of 10 samples driven in the way you describe as best for holding power. I will then test 10 samples driven by a palm nailer. I will then test 10 samples driven by me. I will test 10 samples by me driven into a pilot hole. Etc.
Does it matter for the sake of the test which one you use in the field? I'm not trying to find out what you do in the field, I'm trying to find out if what you say about driving nails is true.
Is it true that a nail driven by a pro in 3-4 whacks has more withdrawl strength than one driven by a palm nailer, me, or driven into a pilot hole? Why don't we drive some and see how much it force takes to pull each method 10 times?
I just want to see if what you say holds water... and if it does, exactly how much ;)Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Yeah, that more recently proposed test is more honest than what you did before, and more likely to be accurate. My posts just now were in responce (look at the reply to numbers) to other posts far earliuer in the thread before you came up with that.But the point is still the same here. you now have all this time and it appears, at least $75 invested trying to prove that you are right and thirty year professionals are wrong, all to no advantage when nobody is going to be switching to a slower, more expensive way of doing this work. The only gain is that we might end up with some more information and you get to stroke your ego back to health now that it's been bruised.But it's still interesting
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin, the only one who has been getting upset about this and throwing... well what ever that was... was you. I have only wanted to talk about this in a respectfull way. Sometimes you have your head on straight, sometimes:
From:
Piffin <!----><!---->
Feb-12 9:40 pm
To:
xxPaulCPxx <!----><!---->
(17 of 121)
69572.17 in reply to 69572.14
That would be the test where your test was totally devoid of validity right? The one where you predrilled for the nails because you are too incompetent to drive a nail?because you were ignorant of the fact that a nails holding power is based on the displacement of the wood?
You were educated about your failings of that theory back then but you continue to proclaim your assinine theory that will probably get somebody hurt someday. Why can't you admit that you are are an inexperienced DIY with absolutely nothing to go on but you baseless thoughts? or at least keep it in context?
or
From:
Piffin <!----><!---->
Feb-13 1:07 am
To:
xxPaulCPxx <!----><!---->
(19 of 121)
69572.19 in reply to 69572.18
What happened is that I get pissed that some crackpot who can't learn to drive a nail or is maybe afraid of breaking his own nails comes up with a crazy idea that screws are better than nails for building a house than then constantly pushes that idea when it is is patently false.
Asking me to prove that nails have their holding power based on displacement of the wood is like asking the HS science teacher to prove that two plus two is four. It's second grade stuff. You want me to prove to you that falling off a roof can hurt too? Gravity works but I don't have to prove it.
You keep pushing your crackpot craap like as though you know something about building when I've already forgotten more than you'll ever know about it.
Drill a hole to make it easier to stick a nail in it 'cause you don't have balls enough to drive it in and it will come out easier too. That simple fact doesn't take much thinking to figure out, but you can't seem to grasp it.
I think there is exactly one person here who needs their bruised ego tended too.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Thanks for keeping it all together in context.
I don't care a whit whether you use screws otr not on your own work, but you started out pushing the idea for others to use them generally with no basis for it. Doing that will lead to structuyral failures. That will get people hurtprotecting those people is what I am dealing with. Fighting against goofy ideas in structural work keeps people alionve and safe. Has nothing to do with my ego. but it was when your ability to perform a simple carpentry task - driving a nail with a hammer - was challenged is when you got all fired up on proving your cockamany idea to be acceptable. That is your ego, not mine. My anger is on behalf of the homeowners that deservve a good safe product. you have a long way to go to prove that your way can do that. You've even quoted from the Simpson charts showing that screws are LESS able to do the job. Same thing I've said from the beginning!
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Paul, stop talking about that dang test and just do it! If you need someone to drive those nails in in less than ten blows, get me a plane ticket and I'll be out there pronot.
I prefer first class and want to fly out of Flint.
I'll verify all results and submit them to the tavern for insertion into the official facts ledger. You also will get one milkbone for your efforts.
blue
I will, but I need to make sure we have some agreement on the basis of the tests themselves. Basing them on the actual ANSI tests and getting buy in from the people who's ideas I am putting to the test is important. I want to make sure this is absolutly fair as possible to all sides. Since anyone can verify the results with their own setup at home ensures I have to be accurate! I'll be saving the money on the 1st class fare for now... but I do side jobs for scooby snacks!
And I still have some other things to take priority - this will fit in the nook and cranny times.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Tsk, tsk Paul....quit teasing us.
Get it on!
Scooby snacks? They sound like they might be a close cousin to milkbones.
blue
I didn't read the initial thread but read thru this one and thought?
So on your journey we get to see excitement,curiosity,process,criticism and so much more.
Already we see that you have discovered that carrots and screws can be one in the same when it comes to Standards. So that in itself says we need to know more.
I say go for it, and if in the future some of what you have rubs off on me. Then I have benefited.
So Thanks for sharing some of your journey. And in the process you learn to swing a 14lb sledge hammer like a man. I'll know who to call for lessons. Grin Grin.
BrokeBack Screws
the saga continues ...
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
I don't know how to quit you Jeff! :"(Rebuilding my home in Cypress, CA
Also a CRX fanatic!
"I don't know how to quit you Jeff! :"( "
I feel the need for a shower ... yet I'm suddenly afraid to take my clothes off ....
Jeff Buck Construction
Artistry In Carpentry
Pittsburgh Pa