Homebrew PCBs

Stefan Trethan wrote:
> well then,
> 
> i just checked my chemical supplier has tin sulfate in his stock list.
> also sulphuric acid would be no problem at all.
> 
> BUT i have not the slightest idea where to get the additives.
> 
> I read this stuff always concentrates at the point of highest potential, 
> preventing plating at this particular point, So you get a even coat
> as the additives move around all the time.
> 
> just BAD that it isn't something simple.

That's basically the mechanism behind plating additives. But 
there is a lot of things going on and all plating additives 
consists of a number of compounds, each specifically doing a 
job, and some are working together. The fact is 
electrochemists don't really know exactly how additives 
work. Developing a new plating additive its an art, not a 
science.

As I said, you buy additives from electroplating suppliers. 
If you cannot find any electroplating suppliers who sell the 
correct acid tin sulfate plating additive, then find a 
business who electroplates tin and ask them who their 
supplier is for the additive they use.

Did you get pricing for the stannous sulfate ? When I was 
quoted AUD$500 for a 25 kg bag, I looked at other options. A 
bit of research and a $5 plant pot solved my problem.