Replies

1. 
   forestgirl | Sep 17, 2002 07:59am | #1

   Sounds like your concern is sag rather than warp.  I have a chart somewhere that helps with this, but cyberworld being what it is, there's a sagulator on the internet.  Here, give it a try:

   http://www.woodbin.com/calcs/sagulator.htm

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

2. 
   DennisS | Sep 17, 2002 08:15am | #2

   12" is a plate shelf. Are you sure you need "book" shelves that deep?

   A good way to avoid at least some sag is to add a trim piece 1" or so along the front edge which will alow you to increase the span some. Another option, if you haven't already purchased your material is to look at thicker material.

   Just some thoughts to ponder...

   Dennis in Bellevue WA

   [email protected]

3. 
   camel | Sep 17, 2002 03:29pm | #3

   If solid wood shelves don't fly with the customers budget, I'll use plywood with the same species as a nosing.  I generally don't like to span over 36" even with an solid wood nosing.  What I think the best way to stiffen them up is to mill a tongue on the plywood and a groove on the nosinsg.  I like to make the nosing an 1 1/4" - 1 1/2" wide by at least 1" thick and mill a profile on it.  The groove can be milled before the profile or after it.  Works good for me. 

   John E. Nanasy