Replies

1. 
   Alan | Jul 08, 2002 08:02am | #1

   KB,

   I often draw-bore the pegs in a mortise and tenon joint.  If I made them so the pegs didn't go through both cheeks of the mortise, the pegs would simply toggle in their holes and crush the fibers on the sides of their holes and wouldn't "draw" at all.  Made that way there would be no point in using them.  Obviously, even if I didn't draw bore the joint, the same thing would happen if the pegs were used to help hold the joint together:  they would easily wiggle back and forth and would do no good.  So, structurally speaking, I might just as well not install pegs at all unless they go through both cheeks of the mortise.

   With modern glues and well fit parts--unless the joint is draw bored--IMHO the pegs probably don't do a whole lot of the work of holding the joint together;  but they still must do some good.  So even though pegs are often used mainly for decoration, they will do some good if they are made properly.

   This is an awfully long winded way of saying that if you're going to the trouble of installing pegs, you might just as well make them properly--so they pass through both cheeks of the mortise.  That way you will have the benefit of whatever they add to the strength of the joint.

   I've made square pegs only once.  I used walnut pegs (for the color contrast) to draw bore the joints on a frame and panel blanket chest made of pine.  I didn't make square holes for them to go through, nor did I make the pegs square for their full length.  The pegs were square only for the depth of the outside mortise cheeks (about 3/8" if I remember correctly).  The rest of the peg was round.  (If, for example, the square part of the peg--the top 3/8" or so was 1/2" square, then I made the rest of the peg 1/2" round.)  I left all of the holes through the cheeks of the mortise and through the tenon round.  The pine was soft enough that as I drove in the peg it easily compressed the pine and made its own "square" hole.  But I don't think I'd try that with a harder wood.

   Alan

1. 
   TomS | Jul 09, 2002 04:34am | #2

   You covered all of that nicely, thanks.  The only thing I can add is that I draw-bore all of my M/T joints regardless of wood specie.  I make my pegs about 1 1/4" long and round the bottom 3/4" or so.  I drive the peg into place and cut to length on both sides of the joint.  I like to keep the forward face a bit proud...that whole 'colonial-crap' notion of what the joint should look like.

   ( I round the peg with a chisel, but I am not a professional and have the luxury of both time and a patient wife.)

   Tom 

2. 
   KRaybould | Jul 10, 2002 03:43am | #5

   Thanks everyone for your helpful suggestions. I've not come across the term "draw bore" before. How is this done?

   My plan is to peg the mortise and tenon joints on breadboard ends of a 12 in wide walnut table top with cherry. I've read Garrett Hack's method when building a carcase where he inserts the pegs after glueup, squaring the top 1/3 of each hole and rounding the bottom 2/3 of the peg.

   I understand that if I insert 3 pegs along the breadboard end that the outer 2 holes should be elongated to allow for wood movement and the centre hole should perfectly fit the peg.

   I'd appreciate any suggestions for the steps of glue-up and draw-boring.

   Thanks

1. 
   Alan | Jul 10, 2002 05:53am | #6

   KB,

   Draw boring is a way to make mortise and tenon joints really really tight--and I suppose you could try it with a "breadboard" end (there I go again;  I was taught they are clamps!).  To draw bore you first drill the hole through both cheeks of the mortise.  Then you put the tenon into its mortise as tightly as you can and stick the drill bit back into the hole and push down hard enough to make a little indentation on the tenon.  You then take out the tenon and drill the peg hole through it with the hole's center about the thickness of a quarter towards the tenon shoulder:  i.e., the hole in the tenon is off-set towards the tenon shoulder.  When you assemble the joint and drive the peg, it will cinch the tenon shoulder up TIGHT!

   When I draw bore I make the pegs about twice as long as they need to be and taper them a bit along about half their length.  This makes it much easier to drive them, and there's less chance of splintering out the hole in the tenon.

   Alan

1. 
   RSRose | Jul 10, 2002 08:17am | #7

   And,

   Try to drill the hole in the mortise cheeks as close to the joint as you can. It should not be TOO close, but it needs to be as far away from the end of the tenon as possible. If the peg is too near the tenon end, it can pop the end grain between it and the tenon end right out of the tenon.

   The closer it is to the joint, the less likely this will happen. The long grain to the side of the peg between it and the joint is not in such danger.

   Rich

2. 
   KRaybould | Jul 11, 2002 02:37am | #8

   Hi Alan,

   Thanks for the added explanation and taking the time to respond to my post.

   KR

2. 
   tom_gattiker | Jul 09, 2002 08:33pm | #3

   If you want the look of a square peg and if you are using thicker stock, could you use a round dowel and then cover with separate cap that is square and that is maybe 1/4 inch deep--just chisel out a square hole 1/4 inch deep for it?  Will this work? 

3. 
   dadron1 | Jul 09, 2002 08:46pm | #4

   On some antique furniture I have seen them go all the way through and not be cut off on the inside, actually stick out about 1/4 inch inside.  The old cabinetmakers didn't waste time on the insides.