Homebrew PCBs

Stefan Trethan wrote:
> 
> 
>>>Note that this brew attacks some plastics - I had left 2 air "stones"
>>
>>:( is PET (or LDPE) OK?
>>
> 
> 
> For some time (months) yes, see my other post, the HCl will form crystals
> on the outside in a year or so. glass is better.
> 
> ST
> 


Nylon is a commonly used plastic that doesn't survive in acid. 
Identifying plastics can be done with the burn test. To check if nylon 
burn some of it and note the smell, color of smoke and the effect on the 
plastic as its burning. Then burn your unknown sample. Nylon burns with 
white smoke, and bubbles while on fire.

I once used some irrigation plastic hose fittings to carry sulfuric 
acid. After a few weeks the fittings disintegrated leaking 20 liters of 
acid on the floor. I later learned they were nylon, so I went shopping 
with a cigarette lighter and burned various brands of hose fittings 
until I found ones that were polypropylene.

Adam