Replies

1. 
   WillGeorge | Aug 01, 2010 12:30am | #1

   Fox wedged..

   The first post out there I found. I wonder why it would be needed?

   http://lumberjocks.com/projects/1951

   I would think modern glues do NOT require any special treatment. Any comments?

1. 
   alanplanesaw | Aug 01, 2010 04:28pm | #4

   WillGeorge

   Thank you also.  That was an interesting article, although it was not the one I remembered.  My focus was on the benefit, or lack thereof, of drilling a hole to relieve stressed caused by the wedge.

   Thank you.  Good "hearing" from you.

   Alan - planesaw

1. 
   jg0258 | Aug 01, 2010 05:48pm | #5

   The hole will help depending on the degree of expansion and the hardness/brittleness of the wood. If your tenon has to fit a 1 or 2º slant on your mortise then no hole is needed, if you are using a hard wood and you have your mortise set at 4 or 5º then the hole helps by giving the expanding "tongue" a bit more spring. 

   Now the explanation for the hole on the Tauton joinery book is as follows:

   " To avoid the risk of splitting out the bottom of the tenon with the wedging pressure drill a relief hole....... This hole will spread out the wedging pressure around a circumference instead of concentrating the pressure at the bottom of the wedge slot, where cracks will occur "

   Joinery page 368

   Hope this helps. 

1. 
   alanplanesaw | Aug 01, 2010 09:08pm | #6

   to drill .... or not

   jg --

   I looked at the Joinery book.   Page 358 -- no hole drilled.  Page 368, your reference, hole drilled.

   Now, what is interesting is that on page 358, the topic is Foxtail-wedged tenon.  They did not drill a hole.  They do a good job of cautioning against wedges being too long.   They also say to cut the slots "close to the edges of the tenon."  I agree with that.

   However, on 368, describing a wedged through tenon, it looks like a disaster waiting to happen.  A wide tenon with a slot in the middle!  Looks to me like a split waiting to happen.  This page is where your quote is.  On the face of it the logic (spread out the wedging pressure around a circumference...) makes some sense. 

   But, that wedge is going to have to put a lot of pressure on its sides to get each half of the tenon to spread to put pressure against the walls of the mortise.  And with that much pressure, I can see a split coming.  Two wedges closer to the each edge would be much less likely to split -- in my opinion.

   For what its worth,

   And, thanks for telling me about the info in the joinery book on the subject,

   Alan - planesaw

1. 
   jg0258 | Aug 02, 2010 04:14am | #9

   Looks to me that it depends on the type of wedge and tenon you are using. In the fox tail wedge it looks like the slot for the wedges is very wide, thus putting less pressure on the tenon, while on the through tenon they seem to just have made the cut with the hole at the end. Either way, stop futsing around with this and just pin them tenons... :-)

2. 
   alanplanesaw | Aug 01, 2010 09:09pm | #7

   ...depending....

   jg,

   My reaction is still one of I would like to see practical proof.   I haven't made thousands, or even hundreds, of wedged tenons, but I wonder if what is theory on paper (or should I say on the computer, now) is in reality dealing with so many variables (the wood itself represents thousands of variables) that the hole is really no advantage. 

   I can't prove it either way, but I have never drilled a hole in what will be a wedged tenon and, to my knowledge, never had a failure. Could be I was just plain lucky.  

   Oh well, thanks for the info from Taunton's joinery book.  I have it, I"ll have to see more of what they have to say.

   Thanks,

   Alan - planesaw

2. 
   mrossk | Aug 01, 2010 12:39am | #2

   The article you're referring to was in Woodwork ing magazine, Aug. 2006. Hope that helps!

1. 
   alanplanesaw | Aug 01, 2010 04:26pm | #3

   the article !!

   Thanks mrossk!  That's it.  I was thinking it was probably either FWW or PW, but I read several so I wasn't all that sure.  Certainly appreciate your help.

   Alan - planesaw

3. 
   flairwoodworks | Aug 02, 2010 01:13am | #8

   Drilling to prevent splitting doesn't help?

   Alan & all,

   I don't know if it doesn't help, but I do know that I have had a tenoned piece split when the wedge was driven in.  I had not bothered to drill a hole.

   I my mind, the hole provides an area for the split to terminate at.  In theory.  Maybe it depends on how well the tenon fits the mortise.  I believe that the tenon's thickness is more critical than the width.