Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@y...>
wrote:
> Phil wrote:
> > 
> > about acrylic - the guys at TAP Plastics told me that it is not acid 
> > resistant.  I wouldn't use it for CuCl because of that.  It worked 
> > fine for AP and FeCl, though.
> > 
> > Phil
> > 
> The three above mentioned etchants normally have acid and pH will be 
> very low (< 1). Acrylic (PMMA) is ok for acid. I made a small 
> electrochemical test cell out of this stuff and have had 20% sulfuric 
> acid in it for weeks at a time and see zero effect to date.
> 
> Nylon is the common plastic you must avoid contact with acid for long 
> periods, even vinegar.
> 
> Of course there is always www.google.com

Nylon is definitely no good in a FeCL3 etch bath.  

Years ago, I had the brilliant idea that, instead of moving the 
etchant, I'd move the board instead (Think of this as sort of a 
Mohammed and the Mountain analogy.).  So, I used one of the index
holes in the board to tie a section of nylon monofilament fishing 
line to the board, and could jiggle the board with that, thus 
achieving agitation (Think clock drive or something like that 
eventually.).  Only, the nylon monofilament line didn't 
even last for one etch before it broke.  Oh, well, back to the 
drawing board.

Dave