Homebrew PCBs

Andrew wrote:
> 
> 
>  > Russell wrote:
>  >
>  > I use 10% Na2CO3 sodium carbonate for
>  > the developing. Unlike NaOH, it's much
>  > less reactive to skin.
> 
> Does anyone use sodium silcate?
> 
> I beleive that is what is in the little
> packets I get from computronics.

Positive resists use a much stronger alkaline developer, like 1% NaOH or 
Na2SO3. Negative dryfilm resist require a much gentler alkaline like 1% 
Na2CO3. I gave up on positive resists years ago, but been told silicate 
is much easer to use than the hydroxide.