Replies

1. 
   LRutherfor1 | May 19, 2002 11:12pm | #1

   Most of the time a joint fails is not because of the type of material used to hold it together, but the wood.  If the material is not dry, when it does, it shrinks and checks.  I use biscuits or dowels for alignment, not for strength.

   Len (Len's Custom Woodworking)

1. 
   RLMillard | May 20, 2002 03:41am | #2

   I don’t believe a joint can be "glue starved", in any way other than not providing enough glue. Wood glues act by penetrating the wood fibers and forming keys, so even moderate over tightening would only serve to force the glue deeper in the wood. I can see where a very tight fitting tenon (or biscuit) could cause some problems, so that is why I apply glue to both the mortise and tenons, or the slot and biscuit. I’m getting the impression that you did not brush glue on the whole joint, and relied on the biscuit alone to hold things together. Also, are the joints edge grain, or end grain? Gluing end grain, without a glue size is risky, and even then it’s not a great joint.

2. 
   gerry001 | May 20, 2002 07:13am | #3

   You've got two possibles here. Firstly, if you should be using a Ryobi biscuit cutter, then you can join a long line of people with problems. Now, you didn't say what kind of glue you used. A water-based glue should cause the bisuit to expand enough to lock the joint and, yes, there will be enough glue left to hold it together. This is assuming you properly glued the joint, of course. In addition, try this --  take your bisuit joiner and cut a slot into some scrap. Dip the biscuit into some water, then immediately put it into the slot (no glue). You should be able to do this will hand force, or at most a light tap. Wait 1/2 hour and try to pull out the biscuit. If it comes out by hand, there's your problem.

   Also not sure how Bubinga takes to different glues. Some woods, like Cocobola or Morada won't work with yellow glue.

   Gerry

3. 
   sschefer | May 20, 2002 10:08pm | #4

   Ed, biscuits are designed to swell when in contact with moisture. They should be slightly loose fitting, (not sloppy), when inserted dry. You didn't say what kind of glue you used but if you used one that requires the presence of moisture to provide the catalyst then you probably didn't have enough moisture in the wood itself to cause the reaction occur.

   Rarely do I ever rely on the biscuit as the sole bonding point. I first wipe the joint with a moistened rag and spread a thin layer of glue along the entire surface of both sides of the joint. The biscuits provide and maintain the joint alignment. I use an acid brush to apply moisture to the inside of the biscut mortise then use an acid brust to apply glue to both the mortise and the biscuit. I do the biscuits last since they will begin to swell almost immediately making them difficult to insert.

   Steve - in Northern California

1. 
   Edward1704 | May 21, 2002 08:45pm | #5

   Steve, I like the idea of applying moisture to the joint before gluing.I had some problem before with Hickory as well- roughing the surface on a dense wood like Hickory was suggested. Next time I'll try both Thanks, Ed

1. 
   Sherwoodworks | May 22, 2002 01:25am | #6

   Bubinga does not work well with yellow glue, it is much like coco, bocote,ebony, etc.  Tight grained, small pored, dense and oily, etc.  I use poly glue after wiping down with solvent, then a quick wipe to moisten with water.  -  Sherwud

1. 
   Edward1704 | May 22, 2002 09:58pm | #7

   Thank you for some sound advise. Sometimes the impression from some less experienced experts is that yellow glue is the best. I also had bad results with Hickory. Ed

1. 
   sschefer | May 22, 2002 10:29pm | #8

   Ed, just a side note, I watched Norm the other morning and he was using Gorilla Glue.. You could tell he didn't have a lot of experience because he used a lot more than he needed. I wish I could see the out takes of the show, I'm sure he lost a few pounds running around trying to clean up the foammy stuff that oozes out.Steve - in Northern California