Re: To Draw Bore or not????
[Re: Mark Davidson]
#16345
07/28/08 11:55 PM
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TIMBEAL
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Braces are always confusing, the standard draw moves closer to the shoulder, the other direction is away from the butt of the brace. This pushes the brace into the square end of the mortice. See, I really put some mud on that one.
I also draw in two direction, a wedged half dove tail, I want that tenon pushed into the angled seat. If you don't you once again risk the joint being pushed in the wrong direction and fighting the wedge.
I tried draw boring a halved and bridled scarf, I now test fit them and prick, then figure. Dyslexia is no help at all in the matter. Tim
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Re: To Draw Bore or not????
[Re: E.H.Carpentry]
#17060
10/14/08 01:09 AM
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Posts: 48
bloveland
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we did a job where a fella that was helping us out was adamantly opposed to drawboring. everyone else drawbored and he did not. when the frame was up you could tell which were draw bored and which were not. it all looked beautiful but there was a marked difference. I say if the relish of the tenon can handle it then by all means do it.
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Re: To Draw Bore or not????
[Re: bloveland]
#17066
10/14/08 08:24 PM
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OurBarns1
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Funny that you ran into a guy resistant to draw boring. A guy I met who just restores old barns said something similar, only he is adamant that draw boring never even existed (at least here in Maine).
He said, quite matter-of-factly, "they put the timbers together, drilled a hole, and stuck a peg in."
Don Perkins Member, TFG
to know the trees...
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Re: To Draw Bore or not????
[Re: OurBarns1]
#17096
10/21/08 04:16 AM
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Posts: 122
Brock Smith
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There certainly is a marked difference in the finished product. I built a 8 posted shed at out worksite last winter. I randomly DB'd 4 of the posts - I can already tell which was DB'd.
Perhaps Drawboring is related more to the MC of wood? An experience framer might chose to 'straight drill' a tenon on a piece of 100 yr old material?
I'm surprised, Don, by the opinion of the fella you speak of. If it didn't happen on the barns in that area and era, where was is standard practice?
From my experiences working with (primarily) swiss carpenters, DBing is not a practice.
brock
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Re: To Draw Bore or not????
[Re: Brock Smith]
#17097
10/21/08 11:51 AM
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Gabel
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I can't speak to Maine, but every pre-revival frame I have examined where I could see a joint that was taken apart was undoubtably draw-bored.
In England several years ago, I was at a Framing Rendezvous in Oxfordshire, UK and was shown an old timber with a tenon on it by Steve Turner. The evidence for how they marked the draw could be seen as plain as day -- this timber was from the time before drill bits with lead screws, so you couldn't just run the bit down the hole. Instead, when the joint was assembled, they had taken an awl and poked around the peg hole, leaving the outline of the hole marked with little pin pricks on the tenon. Then they had offset the drill bit and drilled the tenon. Steve said they had wondered for years how they marked the draw without an auger bit, until someone had looked closer and seen the tiny crescent shaped pricked outline on a tenon.
I wonder how much we all miss when we look at a frame or a timber or a joint?
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Re: To Draw Bore or not????
[Re: Brock Smith]
#17102
10/21/08 08:34 PM
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Joined: Mar 2008
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OurBarns1
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I'm surprised, Don, by the opinion of the fella you speak of. If it didn't happen on the barns in that area and era, where was is standard practice?
brock
I can't speak from having taken apart anything, but in reading about traditional TF, references to Draw Boring appear everywhere. (I think I've even heard of it in furniture making). Anytime I'm studying a topic, if I encounter repeated references (by multiple authors) to something, I feel pretty certian it occured. The guy I talked to who flat-out denied draw boring ever happened is a bit of an oddity. He has restored many many frames and has a good reputation, so I'm inclined to believe much of what he says, but when he said (with distain) that draw boring didn't happen, I just about laughed...and my opinion of him went down a few "pegs." I think he has his theory because he hates the concept of anything "over-engineered." But many texts about old barns here in New England refer to the practice of Draw Boring. I just kept quiet...
Don Perkins Member, TFG
to know the trees...
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Re: To Draw Bore or not????
[Re: Gabel]
#17103
10/21/08 08:44 PM
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Joined: Mar 2008
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OurBarns1
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I wonder how much we all miss when we look at a frame or a timber or a joint?
If that ain't the truth! Neat about the crecent-shaped outlines. Very neat... I think draw boring is one of those things that's immensely practical and so effective that it had to have happened. And it's closely related to wedged through tenons...tightening a shoulder up...at least those we can see. (I have certianly seen these used in furniture) Ken Hume: What about over there, was draw boring standard practice in your opinion, or is it an American innovation?
Don Perkins Member, TFG
to know the trees...
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Re: To Draw Bore or not????
[Re: OurBarns1]
#17104
10/21/08 09:16 PM
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Gabel
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I forgot to mention that the timber we were looking at came out of a barn and was said to be from the 17th century.
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Re: To Draw Bore or not????
[Re: Gabel]
#17105
10/22/08 12:00 AM
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TIMBEAL
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On my last raising the crane operator had mistakenly put his hands on the wrong levers and lifted the truss we had just set and pegged. He lifted the truss, top plates and post 4". All this was hanging on two pegs, one on each side of the english tying joint truss. 3/4" pegs, 4" tenons, when I knocked out the stressed peg to view the damage I noticed the peg had the tenon shape impressed into it and it was cracked. Any draw bored peg will have a similar impression, hopefully with out the crack. I believe one more way to tell if a joint was draw bored is to look for the tenon impression. Tim
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Re: To Draw Bore or not????
[Re: TIMBEAL]
#17108
10/22/08 01:37 AM
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Joined: Feb 2006
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Housewright
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I can attest to draw boring being a common, perhaps standard practice in historic frames in Maine. Quite often you can see the layout marks for the hole on the tenon scratched onto the tenon just like all of the other layout marks were scratched onto the timbers with an awl. I believe that if the holes were misaligned too much they would reduce the size of the pin to avoid straining the tenon relish or pin too much (doesnt that give an engineer the willies!). Some pins come out of old frames cracked but it is hard to tell if the strain was from building movement or just too much strain in the draw bore.
Jim
The closer you look the more you see. "Heavy timber framing is not a lost art" Fred Hodgson, 1909
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