Re: ATM Plywood for a Dobsonian

["Bob May" <bobmay@nethere.com>]

The voids on most plywoods are internal voids rather than exterior ones so
you will be filling cut ends and that is best done with wood filler.
The quality of plywoods is in several areas- the amount of internal voids,
the number of "footballs" (football shaped inserts into the external layer
to replace where a void would have been) allowed in the various layers, the
number of layers in the sheet, the woods used in each layer and the glue
used to hold the plywood together.
Construction grade plywoods don't really care about the appearance of the
surface so they allow the external footballs which look ugly but are
stronger than the void that they replaced.  Interior grades have the problem
of cheaper glues that aren't waterproof.
Needless to say, as the quality of the various items goes up, the sheet gets
more expensive.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net