Replies

1. 
   saschafer | May 30, 2009 04:09am | #1

   As long as the case has a back (so that the back prevents the case from racking), biscuits are fine. You're relying on them primarily for their cross-grain shear strength, which is far, far more than you need, unless you're planning on storing automotible batteries or something like that. I use two biscuits at each end of each shelf. I also use biscuits to join the shelves to the back.

   -Steve

    

2. 
   ring | May 30, 2009 08:44am | #2

   Biscuits are fine for anything except the most demanding situations. I have a doweling machine in the shop, but I reach for the biscuits on most bookcases because they're the quickest setup with little room for mistakes.

   Out of your list, I never use woodscrews as the sole means of joinery. Relying on screw threads to hold in the endgrain of a shelf is (intuitively) crossing the line for me. Using a screw in addition to a dado is fine. I have no scientific data on these options and I'm not waiting to see test results.

   David Ring

   http://www.touchwood.co.il/?lang=e&id=1

1. 
   sapwood | Jun 01, 2009 02:49am | #3

   I have a bookcase in my office made of fir plywood. The top, bottom and shelves are all joined to the sides with three sheetrock screws per shelf/side. The case has a 1/8" thick hardboard back that was probably stapled in. Other than being dustier, this case is in as good a condition as it was just after I made it seventeen years ago. Had I made this for a customer, I'd have probably used biscuits (and nicer wood). The most stress most bookcases and cabinets will ever see is while they are being built, finished and installed.