Just got the go ahead from my engineer to site build two curved glue lams.
One will be 16 1/2′ span 19′ radius-5 1/2″ x10 “
One will be 12′ span 18′ radius-7 1/4″ x 8″
They will be 1x material epoxy glue
I have to source the one by and get it looked at by the engineer yet, then Rikky gets some new clamps.
I’ll post some pics of the project as soon as I have the materials together.
Rik
Replies
Hey Rik, did your Engineer ever consider using a Poly glue instead of the epoxy? Just wondering because that's what I usually always use when laminating curved beams for outdoor use.
Which type of epoxy was specified??
Hey JoeEpoxy because I have a couple of gallons left from a boat building project and suggested it to the engineer. It's the standard West System stuff. I'll roll on a coat of unthinned then smear on a bit of thickened as I clamp up. One beam is inside , the other outside but it will be under a roof and clad as well.
We already have one curved steel beam on site for a moment frame but now the owner wants to extend a large barrell vault. The curved steel beam wasn't too expensive but it takes six weeks to get one done. Also the curved steel beam (5 1/2" x 10" I beam) is made on a big pinch roller thingy and I find that the radius isn't as consistant as I would like , it straightens abit at either end and I don't trust em to match that on a seperate order.
What species /grade of material have you used for curvedbeams?
The only ones Ive come across are large plant built of the type you see in big churches and the like.
I felt like I really had to twist the engineers arm to design these for me.,Rik
Very cool. It's great your engineer is going along with the idea.
What kind of wood are you going to use?
We had some structural-select doug fir 2x that had such good grain and lack of knots that we ended up laminating them with polyurethane for a structural post application that needed a smooth finish.
I always thought that resawing this type of struc-slct doug fir would be ideal for exterior curved laminates since doug fir holds up to the elements well and has such high strength.
DF is one of the standard materials used for glue lams. clear greain would be my choice for this project, but I would probably plan to plane it down to 1/2" to facilitate bending to the radius. That determination always takes some experimentation.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
That is one big lami to be clamping together. You might want to consider investing in a long vacuum bag. It will give you consistent even pressure. Then all you need is a small number of clamps to hold it to the curved jig while it cures inside the bag.
Where are you located at? I'm in Port Orchard. I would love to see this project once it progresses.
Sounds like a lot of fun.
????The home of PO Cedar???Does the smell of that hang in the air out there?
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Edited 10/14/2006 12:40 pm ET by Piffin
Nope. I wish.
Can your lumberyard get them for you?
I know they can around here but they're expensive.
I just talked to my friend at the lumberyard and he told me that he had one made for a wrap around porch with one leg about 16' and the other about 4' and the corner was the radius and it was a 5-1/4" x 12" beam about 25' long and it was 6 grand.
Here's a site I just found. Pretty cool.
http://www.calvertglulam.com/curvedglulams.html
I was thinking the same thing. Why not just order it? These things are made all the time, and then they get to take the liability for it. Those machines that build them under pressure beat the daylights out of a handfull of shop clamps.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
>> I was thinking the same thing. Why not just order it? These things are made all the time, and then they get to take the liability for it. Those machines that build them under pressure beat the daylights out of a handfull of shop clamps. <<Piffin,I agree. My friend at the lumberyard said the beam was 6 grand. Just think of the labor and materials an time spent making these when you can be doing soemthing else will cost as opposed to buying them.Maybe he can't get them made or he can and in the long run it's cheaper for him to make them. I don't know.Joe Carola
Thought about ordering them but a couple of phone calls show that the manufacturers consider these small potatoes and charge you for big potatoes.A half a day to layout and jig up on the floor, a few hours material prep and glue up.May be two hours cleanup. These are small enough for 3 or 4 guys to drag around and place. My labour will probably be less than the shippng costs of these beams. I'm on Vancouver island and the manufacturers are in Penticton /Abbotsford.(south central BC)I'm a carpenter this is a fun thing to do. while the apprentices frame the rest of the roof I can keep an eye on em without wearing a fall arrest harness.And I get to go tool shopping. And I don't hold up closing in the house. And the owner gets his way. It's all good.
Goin fishin nowRik
I don't argue that it can be done onsite or in your shop, But I do think you underestimate hopw much time it will take.
I have built a lot of curved decks, railings and a pair of curved gates. Maybe you have done curves too, but IMHO, they take a lot longer than most people assume, myself included.For discussion, which type of curve is this?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Here is a couple of cheeep architect drawings of the house.The owner now wants radius top windows on the seaside elevation and doesn't want a horizontal beam bisecting the vault at the front entry.I'l post site pics next week.Now I'm really going fishinRik
Get a line wet anyways...That is a nice design from what i can see of it. The owner is right on the arched window tops.What you said about the steel with the staight ends.
I have had similar with curved wood pieces too, I have learned to over arch the ends of those I build a little and/or to make the glue up longer than needed and then trim the end off, The reason is IMO, that the curve always happens via pressure between three points ( or more) and if you make it just to the right length, the end of the curve is only being defined by two points. In steel, that would be the rollers i contact I suppose. In wood it is typoe of form and the clamp locations. stan Foster could sure say more since he builds all those curved stair lams all the time
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin,I've had the same experience with straight ends on curved beams. It is so much easier to just make them longer and trim off the wild excess after glue cure.Someone suggested a vacuum bag, but that isn't going to cut it for these beams, not nearly enough force. Rik probably already knew this.For a one-off, lots of beefy clamps and some helpers to keep things moving are the way to go. Wax the bars so the epoxy does not stick to them. For a limited production run, a firehose press is simple to make and very effective.Bill
Wax on the barsI've been trying to insert wax paper all this time, or ignore it and clean the bars later. Any trouble with the teeth sliding loose on pipe clamps or is this for I-bars like Bessey's with teeth on the bar???The fire hose clamp is a good thought too. Now I finally know what I can do with that fire hose IMERC gave me! I don't do many production runs. usually two matcheing at most on a job.I have a set I made up for smaller materials like the railings of separate gigs that I screw to a floor to define the curve, and adjustable to about 16" wide. I can lay out the curve on subfloor or a deck and screw these to it at appropriate intervals, insert my glued lam strips, and then shim them snug, and need very few shop clamps. It is pretty easy to lay waxed paper into the bottom of these before assembly is why that is what always came to mind. For anyone else out there, a tip - I usually save a couple rolls of the heavy waxed paper backing off ice and water shield for this sort of thing
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I was thinking Jorgensen I-bars, but it can also work on pipe clamps, just not as well. On both kinds of clamp the clutch disks bite into the steel to hold the position. On pipe clamps, only wax the side of the pipe facing the work, or they'll never grab on the smooth sections (without previous clutch scars).I have found that pipe clamps deform too readily on heavy clamp jobs, while the I-bars stay much straighter.Wax paper or polyfilm is still a great idea on the lower clamps, but a real pain on the uppers...gets in the way. Great tip on reusing the I&W backing, BTW.Bill
So I am wondering (maybe I'll get to do something cool like this someday)
Could each layer be glued and screwed with the same results? (less clamps involved)
Do you glue it all at once, or layer by layer?
Treat every person you meet like you will know them the rest of your life - you just might!
No is the answwer to the first Q. Back when I was barely starting to do carpentry, and most of that rough framing, a couple of friends asked me to build them a lam top table from 2x4s - they had the materials and would provide dinner that night.so I brought my trusty screw gun and some glue, cut the 2x4s and commenced to making a mess. I couldn't believe that this was what they wanted for a kitchen table. But she kept saying that she had seen it in some magazine just like that. Keep in mind this was back in the seventies.I was by their house again a couple months later for dinner and found that the table had grown worse. I was sooooo embarrassed! But they seemed to love it for some reason. Thankfully they moved away not long after so I didn't have to look at it again after the landlord burnt it.There is no way the screws will develope enough pressure to force the glue to comply and lay evenly and get all the air gaps out for a good joint. Screws would also resist wood movement which is natural. And they would be hard on the planner when you go to finish the thing up. Maybe that not necessary for a structural beam, depending....For curves - all at once is hoiw I do this, but the hardest part is to have a glue with plenty of open time so you can lay in all the lam pieces and get them curved within the form. as you do this, they slide along each other. That takes some time and a glue with fifteen minutes open pot time will not be acceptable. a slow cure epoxy is best for control of time with the charts they have. An epoxy can be customized.Here is a shot or two of some oak stair treads I laminated. I walked on them two days ago. built in '98 if I recall....and still perfect.and a couple shots of the adjustable gig set up I mentioned earlier. I set the dowels into the holes and fit the other half of each pair down over the dowels, then pinch-shim the material at the dowels. Sometimes I need to add the clamps and sometimes not. I have a bunch of bar, I-bar and pipe clamps, but this could be done with an investment of more time than money. I have used the same for the treads shown and a few railings. I had some others a bit different that I wore out before that.
Another way to do this would be to have some steel angles made up or just cut them off angle stock and drill holes in them to screw them to the floor, leaving the second leg standing up. I have never tried that idea, but it might require a web welded in to keep it from warping under the pressure.
For any of these, I staple the heavy wax paper to the subfloor or deck first, as a drop clothe. Use the wax or waxed paper for anything that will come in contact, or it could become a part of the whole.NowBack to your regularly scheduled thread in progress. IO'v hi-jacked it enough. I'm looking forward to learning his glue methods for this heavier work. I think most commercial glue lams use resorcinol for its long working time and low creep. Folks on the coasts around boat bulders tend to use the West system epoxy be3cause it owns much of the market for laminations in boat building.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Thanks Piffin
I used to read a lot about making instruments & had a book on laminating banjo rims w/veneer
Then I had a friend that laminated his own recurve bows with the firehose pressure technique.
This is fascinating stuff.
Someday I'll laminate some beams - for now I get to watch...
Treat every person you meet like you will know them the rest of your life - you just might!
Nice treads!
Also, you must have kept the ripped strips in darn good order...I was looking at the second JPG. thinking, "how'd the bojangles did he bend 1x4 on the flat" ;-)
How thin were your rips?
Artcoma, in that first pic, how'd you make that post/curved beam connection, and what glue did you go with?Got any closeups of the clamping blocks you made??
Hey Joe thats just a temporary post toenailed up.The plan shows 24" square columns stuccoed but now the owner is waffling and maybe going stone facing for the bottom half and board on board cedar for the top half.I used west system epoxy with slow hardener because I have a few gallons in my shop left over from another project, and the engineer liked it.It's expensive but easy to work with and dries hard(no creep) and makes a great sealer cause its raining like crazy now.I'm using the same clamping blocks to glue up the fascia so I'll take some pics when I'm back at it,They are just some scap I blasted together with a spiker, I have been off for two days now with a crappy cold that stole my voice. I also have to spend a day or two next week on another project so I'll get some pics up by next weekend.cheers Rik
Nice job.I had some west slow stuff once, probably still have some. I was doing a glue up with day temps approaching 90° and it let us have maybe a half hour working time is all in that. Set up two hours later.Then I used it for a door repair the next winter, forgetting that it was slow cure - and I was working in a garage where the temps got down around forty. I came in the next AM and started to unclamp and stuck my hand in the ooze-out for a rude wake up call. It took three days for that door to kicK! LOL░
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
1x4 hunh?IIRC, they started out at 5/4 x 8, more or less.I carefully selected for grain first, then did keep amtched sets. Simple enough when you are ripping to draw some match lines on the faces with pencil. But it did drive us crazy somewhat, with so many treads after awhile. Rips were about 3/8" I think. The smallest radius might have gotten an extra pass through the planner.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
you must have been using the extra thick kerf blade if they started out x8....that second jpg. sure looks to my tired eyeballs like the matched grain sections ended up around 4"
could be an optical delusion, though ;-)
narrow kerf. That prime oak was not cheap!
besides, I don't care for eating oak saawdust.But it might be that I had a selection up to 8" wide
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Rik, I’m usually gluing up curved deck beams using the same stock I’m using for the joists. I pick out the clearest joist stock I can, and have it bandsawn split in half (comes out less than ~3/4” thick x whatever width the joist stock is) then I plane down the sawn face. With 2x8 joist stock, I end up with 5/8 x 7.5” pieces for the laminations.I trim the joist ends to the curve I want, then use those ends to bend the laminations around on to.I’ve done a few large curved pergola beams like these. Sounds like what you’re intending to do. The beam in the front here is 24’ across.
http://i11.photobucket.com/albums/a173/JoeWood_/Misc/FanArbor.jpgYou might find this useful for your project! Instead of building full sized forms, I just build a table surface (two layers of 5/8 plywood and framework underneath), larger than the actual beam, scribe my radius on to it, and position/fasten these clamping blocks along the radius. This lets you pull all the laminations onto the curve. Then we put more clamps between those to draw everything up tight. We actually use more blocks and clamps then what I’ve shown here!
http://i11.photobucket.com/albums/a173/JoeWood_/Misc/Fan_Beam1b.jpghttp://i11.photobucket.com/albums/a173/JoeWood_/Misc/Fan_Beam2b.jpgHardest part in making the clamping blocks is bending the steel straps around tightly.
http://i11.photobucket.com/albums/a173/JoeWood_/Misc/Fan_Beam3b.jpgWe glued up the beams in two 7 layer stages. Hardly any spring back. I’ve done a few arches using this same technique with the strapped clamping blocks. Pretty nice not having to build the forms, and none of these clamp blocks split or pull out under the considerable pressure we put on them! You’re problem though might be that since your beam is going into a house, you’ll probably need some engineering done on it.
Edited 10/16/2006 5:39 pm by JoeWood
Wish I had a better bandsaw!That is about the same clamping procedure that I am going to try.
I'll be able to do this right on the subfloor of the house so I can scribe the radius directly
for the smaller beam.For the bigger one I have to match the curve of an existing steel beam so i'll make a pattern of 1/2" ply and tack that to the floor. Hopefully I'll have time tomorrow to do a dry run of the smaller beam.
Those pics are fantastic by the way. Thanks for the info.
Both of my arches will be clad or drywalled .Cheers Rik
Wish I had a better one too Rik! I get that milling done at the yard where I buy my PT. They have a big monster bandsaw for all their resawing work.here's the .skp file in case anyone's interested.
Some more pics of the fascia on and a couple pics of one of the coolest simpson hangers I've seen in awhile.Rik
Whereabouts is this house? Really nice work.
Hey Tim thanks.Use Mapquest.ca and type in -2765 Seaview Drive Victoria BC CanadaCheers Rik
I was wondering if that was Royal Vic. Yacht Club in the background. Not far from my grandfather's boyhood home on Foul Bay Rd.
Finally stopped raining for a minute. Here is some pics of the project so far. I glued up half of the smaller beam today, will add 6 more plies on fri.
My lumberyard can get 20' 2x6 resawn for me for the bigger beam. So I'm good to go.Thanks to All for the info and advise,I'll post some more pics once I get both beams up.cheers Rik
Hey Rik, could you show us a cloeup of those clamping blocks you ended up using? I'd like to see your solution.
Nice! Supports the old claim that you cannot have too many clamps!
Gasp! Omigod! Those wouldn't be engineered trusses, would they, up in that complex roof frame?
If so, give us some more pics of that part, when you are clicking more of the curvebeam makeup.
An update on the project:Heres some pics of the beams inplace. I had some more of the glue ups but my camera malfuctioned, oh well.Material prep glueup and planing/sanding took less than 8 hrs per beam with two guys.They turned out great less than a 1/4" springback.too bad they won't be exposed.At the entry there will be 30" square posts for support and in the living room the area under the beamm will be all curtain wall i.e. storefront type glazing system anodized aluminum frame with 4' x 8' glass doors.My next challenge is to make curved fascia board for the vaulted areas. I'm starting that tomorrow.Cheers allRik
Ric,Very good looking work. One can never have too many clamps.Chuck Slive, work, build, ...better with wood
Maybe I should restate the curved part.... these are going to be arches ....in a vertical plane to support two different barrell vaults..... ..........Rik........
Archtops - got it - fast reply!
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
If it were me, I would do this using two-part laminating adhesive, and a bag press.
Here is a source for long bags. http://www.vacuum-press.com/bags.html
Having done curved glue-ups using all the possible combinations of glues, clamps, cauls, clamp jigs, screws, bolts, yadda, yadda, yadda, I can say there is nothing quicker or easier than vacuum bagging.
Clamping wears me out, gives me big blisters on the heels of my hands, and just doesn't do the for-sure pressing job that a bag job will do.
The bag may hold the laminations together but I'll still need the muscle and clamps to bend the curve unless you have some tecniques I havent seen yet?Rik
I'm sorry. I saw the pics and read the posts, but I thought your lams were to be vertical. Think LVL.
Now I understand that you want the lams to curve, as in glulam. In this case, the lams need to be thin enough so that it will only take a couple clamps each end, to fix the whole bagged up thing to a bending form.
Are these beams for show? Or will they be all covered by finish? Because, if they are for show, I would never do on site what you are considering. The client wants the look, the client's going to have to pay for it. Get some drawings, book the job in at a supplier, and go work on something else.