Posted for "Nicholas Paczkowski" <npaczkowski@telus.net>:

 I have, what may constitute a 'dumb question' but, on the premise that 'you
 will never know until you ask' - here goes.
 
 I use 'peel-ply' on virtually all of my layups. When I peel it off, it
 leaves a nice 'toothy' surface. However when I need to bond to that surface
 with another layup I dutifully sand the area it with 80 grit and wipe it
 clean with acetone. In other words I replace the 'toothy' surface left by
 the peel-ply with a new sanded surface. My question is: "Is this sanding
 necessary"?. Could I just bond to the 'toothy' surface created by the
 removed 'peel-ply without sanding it? Am I getting a better or worse joint
 by sanding it?
 
 Thanks for your guidance.
 

[As long as you leave the peel ply on the intended bonding site right up until the very last minute before removing it, the peel-plied surface provides an ideal texture for subsequent bonding, one that is well protected from contaminants negating the need for any additional solvent cleaning as well. If, OTOH, you remove the peel ply well in advance of bonding it is very likely that its surface will become contaminated and require, at the very least, a solvent cleaning, and in the worst case, a complete surface prep, right down to coarse grit sanding.  I hope this helps.   <Marv>    ]