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I’ve got a small timberframe project coming up and considering the best way to cut and clean up my tenons cut in 8″ X 8″ timbers. My mortises will be cut using plunge routers, drills and chisel, but I’m looking for some thoughts from the experts out there on the tenons. Thanks.
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Mortice and tenons?? 8"x8"??
What are you ?? A masochist?? :)
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Mark
maybe I'm in the wrong disscussion group, but it seems to me that I've read timberframe articles in Fine Homebuilding. I'm building a 20' X 22' add on to a home with 3 bents/2bays. From other books and articles that I've read 8" X 8" post and principle rafters are not at all uncommon. I'm not interested in purchasing one of those 16" circular saws and thought I might get some ideas on cutting and cleaning up tenon cuts from someone who makes a living doing this kind of construction.
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Kim I used 8x8 on a massive deck that was built on the post and beam principal.
We used a gas powered quicksaw that is modified for a 12" carbide blade and that seemed to work to our satisfaction.
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Gabe
What is a quick saw? And can you get the kind of accuracy for finish joints?
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Kim,
A quick saw is a chain saw that has been modified to take a circular blade ( usually a diamond blade for cutting concrete ) but in this case it seems Gabe has fitted a tungsten wood blade for deep cuts ( brave man ?? ).Yes Gabe, how about the accuracy?? Not my cup of tea I'm afraid.:)
*Mark the control is quiet good, the power is actually the weak point. The drive is not as positive as I would like to see.The saw is much more accurate, IN THE HANDS OF THE AVERAGE WORKER, than a chainsaw would be even though there is the same amount of centrifigal force at start up.
*Gabe,About chainsaws...Build a few log homes and you can cut thin pencil lines in half....Challenging any saw...any time,Jack : )
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Just finished a post and beam great room project -- 8" x 12's, 8" x 8"'s and 6" x 6"'s. I was a novice in the beginning (first timber frame), but quickly learned how to use a tool that even Norm Abrams doesn't own -- a PRAZI beam cutter. Similar to the principle that Gabe discusses above, it's a $120 chain-saw attachment to my worm-drive. the chain is a mere 3/32 thick, and I found the accuracy to be quite good, although I found that after some use, it would need to be readjusted to stay true.
I crosscut as well as ripped with the beam cutter, with good results. There was a fair amount of tear-out on a rip cut, but if it was a finish cut, I tacked a scrap of plywood to the beam to take the brunt of the chain. I also initially had a tough time with visibility of the cut lines, but practice, and a different stance, took care of that.
I cut most of the tenons with the beam cutter, with good results. Jack is right -- after a bit of practice, I could cut very accurate cuts with the Prazi. As far as power, I was cutting through recycled doug fir (fairly soft) with no problems. Cleaned up all cuts with chisels, planes, etc.
The results were wonderful. Now I'll have to find other uses for the beam cutter (gang cutting rafters, maybe?)
One last thing -- I think Prazi has a web-site, if you want to check it out. Do a search on "Prazi", I think.
*Actually, here is the homepage for Prazi (I just dug it out)... http://www.praziusa.com.
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Remember Jack I said "in the hands of the average worker" You forget that we're above average.
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I've seen the Prazi advertised and will look into it. This would be the first timberframe for me also though I've been interested in building timberframe for years.
Just finished reading The Timber-frame Home by Benson. And not knowing if this will be the last, I'm reluctant to invest too much in new tools. Already got my eye on Barr chisels, bullnose planes, another plunge router, etc., etc.
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Kim I got my start on timber frame stuff. My grandfather build timber frame barns and would lug me along. You have two ways to cut the tenons.
1 Find, borrow or steal a 6 tooth handsaw. As far as I know no one makes any. Or you can still find a good 10 point saw and find someone in your area to retooth it that would work.
2 Power tool buying time. When I have to work with 8x8 I use a 10" skilsaw and clean up with a timber slick. This you can still buy through mail order shops.
trying to do the job with out the propor tools will slow you down and make life just rotten for you.
Wish you the best on the raising!
*Kim,the prazi works fairly well and is inexpensive....they also don't last very long for heavy users so don't think you have to build multiple frames to get your money back...I use a little Stihl free hand and amaze my self at how accurate one can be with some repitition. Also use an inexpensive electric saw that has lasted forever and is very powerful and too d**m good for how little it cost me..around $60 I think.Sawing with the b front of the blade,Jack : )
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I agree with Jack, that the Prazi can't hold up in heavy use, mainly because it was constantly "under-foot" (in other words, the blade received a fair amount of abuse after the cut), but replacement blades were just $15 dollars. I tried once to sharpen the blade like a normal chainsaw blade, with poor results.
I also agree with Bill -- no matter how many power tools you get, I used a wide variety of hand tools constantly, and with good results. I also read Tedd Benson's book, but opted to not purchase many of the "special" hand tools available, since I wasn't sure I would be doing another of these soon.
For what it's worth, I had more problems with the mortises than with the tenons. They were either too big, or not straight, which required a fair amount of man-power checking and re-checking for fit. I got much better by the end (of course!)
Good luck!
*Kim: I've cut 7 timberframes in the last year, My prefrence is the electric chain saw. be sure to score your lines well,Practice on a test piece, cut an eighth away from the line then brush to it, clean up with a slick, block plane or what ever you're comfortable with. check with a crayon covered straight edge for high spots. The chainsaw with a little practice will cut your mortices as well Good luck and don't forget the pine bough on the peak
*About 60% of the joinery on the structure will be splines, i.e. Both members are mortised with an 1 and 3/4" hardwood spline between. The reason being that most of the tension in the building is not in the compression direction but in the expansion direction. The rest of the joints where the rafters meet each other and where the rafters meet the priciple posts will be non-housed mortise and tenon...More like a lap joint. I'm thinking a timber slick issomething like a large chisel correct?
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Kim you're right a timber slick is the mother of all wood chisels. They come in all sizes biggest I ever saw was a 36" used for logs. I like the 12" one I have. Remember these are a trim item tool. They are best used to clean up a piece
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May I sugest a threaded rod instead of a hard wood spline? If you are worried about expantion then this is your answer. Cut a mortice 1 inch wide in the top, centre of the conecting member, 8 to 10 inches long and 2 inches deep, at the end of the channel cut a pocket to except a large washer and nut, usually 4 inches deep, wide and long. This is all in the top of the member so it isn't seen or covered by flooring, in a case where it is exposed, make a plug to fit. The post is drilled through to except the 3/4 rod. This allows you to draw the members tight to the post from both sides, and with 10 inches of wood to pull on the risk of future seperation is nil. If I had your e-mail adress I could send you some drawings.
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Steve,
Click on Kim's name or anyones and their pertanent info along with email address pops up.
Jack : )
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Man Steve, where were you when I was struggling through my timberframe job?
*Thanks for the tip jack
*Steven;I just stumbled across this page about a month ago, Other than that I've been up here in southern Ontario putting thin lines on big wood and cutting to them.The place where I work did an octigon about 6 months before I started. I'm just waiting for another to get sold.
*Steve, in fact, I have been thinking about using threaded rods at what I consider the critical points. My thoughts were to put the rods through both joining timbers and the hardood spline. I am reluctant to depend upon the joint without the rod because of expansive nature of the joint.
*Kim; If you could e-mail me a copy of your plan I'll see what I can suggest, there are many variables to consider when making joinery decisions, sometimes the hardest part is visualising the finished product.I'll take it to work and all the guys will kick it around.
*Kim,We use electric chain saws. Stihl and Huasqavarna. With a chain saw you have everything you need, motor, cutter and the ability to cut to a line on both the "top" & "bottom". The only thing missing is a way to cut using a jig so you do not have to free hand it. To make a chain saw jigable (come on it is too a word) we had a machine shop drill 2 holes in the bar close to the motor. We than bolt wood blocks or MDF to those holes to make almost any kind of jig you can imagine. Including one that cuts the sides of a tenon very accurately. Once you figure out the part about jigablity let your imagination run rampant. Good Luck, Dormer
*DormerApprecate the idea about jigability. Been out of town for a week, that's why it's taken so long to respond.
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I've got a small timberframe project coming up and considering the best way to cut and clean up my tenons cut in 8" X 8" timbers. My mortises will be cut using plunge routers, drills and chisel, but I'm looking for some thoughts from the experts out there on the tenons. Thanks.