Homebrew PCBs

>Hi guys,  I am wondering what people use to coat the copper traces to
I think what you want is to tin the copper not soldermask it.

You can get a tin plating solutition that you dip the board in and it will
plate the copper areas.  You can it actually makes soldering easier and is
much less likely to corrode than the copper.

Soldermask keeps the solder from flowing into any area it covers.

Hope that helps.
Ken