Homebrew PCBs

On 28/09/2011 16:31, designer_craig wrote:
> I used AP for years it worked out great for me. The solution doesn't
> keep too long so I would just make up what I needed for that job.
> Heating is the key, it doesn't work unless it's hot. Also, a few ppm of
> HgCl2 really increases the etching speed but that adds a toxic element
> to the mix, but doesn't take much at all. These days, Hg is one of those
> bad actor metals, though I must admit to haveing quite a few milligrams
> in my teeth and played with a few Hg covered pennies. Unless you have a
> proper and legal spent etchant disposal process it's use is not advised.

When I used AP many years ago, I used to add a small amount of common 
salt instead of HgCl2. It made it a lot faster.

Leon
-- 
Leon Heller
G1HSM