Homebrew PCBs

I've used the sponge method on boards up to 2 ounce copper.  It just
takes longer.  Definitely get the green film if using the sponge
method.  It is very effective in protecting the toner from the rubbing
action.

A 75mm by 100mm board with 1 ounce copper takes about 5 minutes to
etch.  I also cover all unused areas with toner to reduce the rate of
etchant exhaustion.  This size board takes about 1 ounce of etchant.

--- In Homebrew_PCBs@yahoogroups.com, "schabtach" <adam@...> wrote:
>

> 
> Alternatively, has anyone tried the sponge-etch method with 1 oz.
> copper stock? 1 oz. / 0.032" stock seems to be readily available.
> 
> Thanks in advance for any replies.
> 
> --Adam
>