[ATM] Re: Warping plywood

[nfnik-atmlist at yahoo.com (nfnik-atmlist@yahoo.com)]

You may not want to hear this at this point, but I have found that 3/4 inch _marine_ plywood (usually birch) is quite resistant to warping.  This stuff is not cheap but one sheet will build a box and all bearing surfaces for a stand over 3 feet high that will handle up to a 10' scope..  1/2 sheet would probably be fine for just a rocker box assembly.  
 
The stuff is also heavy: my solution was to cut lots of creative looking holes!  If you have a scroll saw, you could probably make representations of whatever astronomical delights you desire.
 
I think it is available in 1/2 inch as well.
 
> After cutting up the 
> box pieces,they began warping.This made dado and
> gluing a 3-ring horror 
> show with 2 intermissions.Got any ideas?
> regards,Ron

Ron,

Though you were talking about cabinet carcasses, the
same thing holds true for mirror boxes, rockers, and
other scope components.  Winter is a hard time to work
with sheet goods because of low humidity, especially
if you heat your shop.  It is important to store them
properly so that they lose and take up moisture
evenly--vertically on edge with a generous air space
between them.  If the panels cup anyway you can try
moistening the concave side with a slightly damp
sponge just before glueup, though sometimes this
results in a very wavy panel.  You might consider
moving the panels indoors and letting then "cure" a
couple days before assembly.  In my experience
components tend to flatten out once they are
assembled.

Ross