For sure, the smallest diameter can't be bigger than the hole.Originally Posted by Mike Holbrook
Jack
Guest
For sure, the smallest diameter can't be bigger than the hole.
Jack
Member
The first time I tried drawboring was when I built my Roubo, and it's one of those "Holy crap!" moments. The result was so rigid, the tree might as well have grown the M&T joint. It was one with the wood. Those things will never fail. Peter Follansbee and J. Alexander have studied a number of drawbore joints from the 17th century and later, and they are still solid.
I did manage to blow out the far side of a mortise on a project one time when I didn't point the pin well enough. As it deflected from the offset, the edge caught the mortise end grain. Make sure your pins are straight and pointed enough, and definitely make sure you split them out of straight grain. There's a lot of strain on them, and any short grain is likely to fail.
Steve, mostly hand tools. Click on my name above and click on "Visit Homepage" to see my woodworking blog.
Member
Mr. Kingshott has a segment in his Mortise n Tenon video that covers how to do draw bore MT's. He also shows a trenail ( tree nail ) from HMS Victory that he obtained.
His video is not expensive and it covers the MT joint very well.
Sure do miss him.
Guest
Me, too. Might want to pick up his dovetail video, too, mastery in action, both videos.
Jack
[OP]
Member
I found both Kinshoot's DVD's, Mortise & Tenons and Dovetails, about $18 each. Is he showing hand tool techniques? I see his books too but $70-$130 ea on Amazon, ouuch!
Guest
Yes, it's all hand tools on those dvd's, get them while you can. You don't need the Making Tools book untill you start making infills and the like; but the other two (Sharpening and Workshop) could be nice, only $1-5 used. The Joints book is very good, but only if you have big questions about joinery after watching the dvd's.
Jack
Last edited by Jack Curtis; 12-30-2011 at 7:34 PM.
Member
I've recently bought all of Kingshott's DVDs new, and all his books except Making Tools used. The used prices are very reasonable, the new prices reflect some kind of limited supply insanity. I'll be doing a review of the whole slew soon on my blog. All the material is excellent. He's an engaging teacher. There's some repetition between the books because they were written over several years, not as a particular set. The DVDs are all hand tools. The books are mostly hand tools, with some machine info (how to sharpen machine blades, use of machines in the workshop, etc.).
Kingshott appears to have been quite a treasure, and he's left us a fine legacy. What I find particularly interesting is that he came up in the English apprentice system just after World War II, so in some ways he was the among the last of a breed. He also liked to use Japanese tools, but shows primarily English tools in his books and DVDs.
Steve, mostly hand tools. Click on my name above and click on "Visit Homepage" to see my woodworking blog.
[OP]
Member
Thanks for that info Steve. Do you think the Mortise & Tenon & Dovetail DVD's are the place to start then? I am most interested in drawboring. I have found quite a few free videos/instructionals on dovetails and mortises & tenons at places like Derek Cohen's Blog page.
Member
The M&T DVD is excellent, though on drawboring doesn't show any more than Derek does. The one difference is that Kingshott marks the tenon by inserting his bit and turning the brace backwards, so it marks the position of the hole in the mortise without actually drilling, whereas Derek uses a brad-point bit. Other than that, the information is the same. Kingshott also uses a similar drawbore pin, which appears to be round in cross section.
Steve, mostly hand tools. Click on my name above and click on "Visit Homepage" to see my woodworking blog.
Member
If Joel is still around, I'd like to pursue the way an oblique cone works. Since it is round in cross section at any point on the shaft, it cannot draw the joint tight simply by being rotated. But it could do so by having its axis tilted as it is pushed and twisted. I think (not having used one) that the idea is to first push in the pin with the straight side contacting the tenon and the tapered side contacting the near side of the mortise. This will cause the axis of the pin to tilt a bit relative to the axis of the bore. Then if the pin is simultaneously rotated 180º and pushed in a little bit , and pulled to the same axis as the bore (a complex three-dimensional move, but probably feels natural and the user only is thinking about the twist) when the straight side of the pin is against both sides of the mortise and the taper side against the tenon and the axis of the pin aligned with the bore, the joint is drawn tight.
Is this making any sense? I am not skilled with drawing programs.
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