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View Full Version : To drawbore or not.



David Ryle
12-13-2017, 11:11 PM
My daughter is returning home and is needing a new bed frame, an ash tree that had been growing near to her bedroom during her childhood had been harvested a couple of years ago and I thought it would be nice to make a shaker style frame from that. Head and footboard are completed my thoughts are regarding the stretchers connecting the two. I don't particularly want to use bolts and I've been considering using draw boring. In the short term it would be satisfactory, my concern is that if the frame needs to be taken apart there is a good chance that it would be difficult to acheive a snug fit the second time pegs were driven through. I haven't yet cut the mortises in the posts ab
nd before I do I thought I would ask if anyone had a better idea.

Roger Nair
12-13-2017, 11:39 PM
My background is in timber framing, so I would offer a few cautions on draw boring. Your pegs should be tapered and not driven in tight as possible, try to drive the pin until the joint tightens and lightly drive until the tension starts to build rapidly and no further. The object is to have the pin act as a spring, therefore room must be present in the bore for a springlike action can occur. If you continue to over drive the pin several things can happen: The end grain of the tenon can blow out, the pin can crush or the face of the receiving piece can split.
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Another method could be wedged thru tenon typical of Craftmans style.

David Ryle
12-13-2017, 11:51 PM
I thought about using a through tenon but I was hoping to use a stub tenon.

Malcolm Schweizer
12-13-2017, 11:56 PM
I would rather use a wedged joint of some sort. Since a through-tenon might protrude too much, you would need to be creative. Make a mortise and tenon joint with a hole in the side all the way through- wedges driven from opposing sides- trim flush. When you want to disassemble, drive the wedges back out. If damaged or no longer drive flush, wedges are easy to replace. You could leave the inside wedge long to allow for adjustment. The hole in the tenon needs to be offset just like a drawbore pin hole.

Another option (probably better) is a loosely pinned tenon, and then a hole for a wedge to be driven that snugs it up. The tenon goes into the mortise first, and then a dowel is driven in that is not too snug, pinning the tenon. The stretcher has a rectangular hole that terminates just beyond the bedpost. A wedge is driven down into that hole and it snugs up the joint. The wedge can be a decorative feature intentionally left protruding. This is the easiest joint to snug up as it loosens over time, and is easy to take apart.

John Schtrumpf
12-14-2017, 12:58 AM
I don't know how well it would hold in a bed frame, but you might think about a wedged half-dovetail through tenon:

https://hillbillydaiku.com/2015/12/15/blind-dovetail-thru-mortise-and-tenon/

Circled in red, is a variation of that joint, that I used to connect the right side of a drawer box to the shelf above it:
373784

Matt Evans
12-14-2017, 1:51 AM
I don't know how well it would hold in a bed frame, but you might think about a wedged half-dovetail through tenon:

https://hillbillydaiku.com/2015/12/15/blind-dovetail-thru-mortise-and-tenon/

Circled in red, is a variation of that joint, that I used to connect the right side of a drawer box to the shelf above it:
373784


I used that wedged half dovetail joint on a walnut bed frame I built for a young niece 4 years ago, and it has stood up well to a very active childs antics. The concern there was that a regular wedged through tenon would be hazardous to the neices shins, so the dovetail tenon only sticks out about 3/8", and I trimmed the wedge flush with that.

Warren Mickley
12-14-2017, 12:10 PM
<p>
We use wedged tenons in historic looms. There is only one wedge; I have never seen a double wedge like in the link. The angle of the wedge is matched to the upper slope of the mortise. I would leave the wedge protruding about a quarter inch so it can be tightened at a later time. A loom is much like a bed in that there is there is a lot of jarring going on, a lot more than a bed. Weaving as done in the 18th century is quite an athletic pursuit, not like someone at a craft festival. It is a lot more tiring than jogging and guys did it all day. Heavy looms needed cleats on the floor to keep them from walking across the room. And like beds looms need to be disassembled for moving.</p>
<p>
Regarding a drawbore joint, there is no problem with dissasembly and reassembly. We routinely take these joints apart for restoration work. The pins are tapered and we hit them from the back to remove and keep track of the pins so we can put them back in the same places. If you use this system, make sure the back end of the pin is accessable.</p>
<p>
Here is a loom with wedge joints in the near corner:</p>
<p>
http://www.stillwaterstudio.org/wp-content/uploads/2011/04/me-and-loom-copy.jpg</p>