Homebrew PCBs

Leslie Newell wrote:
> steel go rusty. Some plastic containers are slightly porous so over time 
> acid fumes can escape and rust any nearby steel.

Does anyone know if those black plastic "accordion bottles" used for darkroom 
chemistry fall into this category? The ones I have are made from HDPE, if that 
makes any difference.

> If you want to neutralize it, keep adding sodium bicarbonate (baking 
> soda) or sodium carbonate (washing soda) until it stops fizzing. Washing 
> soda is probably better because baking soda will fizz a lot so you will 
> need to add it slowly. Another trick I have heard of is to mix it with 
> cement. That way you end up with a neutralized block.

Admittedly this was for neutralising FeCl, but I was told that mixing the 
stuff with Plaster of Paris would neutralise it and leave you with a solid 
block that can be thrown away with normal rubbish. Can anyone confirm this?

I've got a 2-litre bottle of extremely diluted and somewhat polluted (with 
etch-resist pen ink, of all things!) FeCl sitting in my cupboard, it's gotten 
to the point where the bottle is lined with brown sludge, the bottle threads 
are covered in green and white crystals (maybe CuCl?), and the solution itself 
is dark brown and useless.

Still, there's another 2ltr bottle with 1.5l of CIF "hyper-activated" FeCl in 
it, which works rather nicely in a bubble etch tank.

-- 
Phil.
ygroups@...
http://www.philpem.me.uk/