Drain cleaners like Red Devil or Crystal Drano are sodium hydroxide.
It my have little metal shavings in it to make it fizz. Since I use it
to strip negative resist, I am not worried about metal shavings. I am
not sure if it would cause a problem with developing positive resist
as I have no experience with that.
--- In Homebrew_PCBs@yahoogroups.com, "Ben" <bhleavi@...> wrote:
>
> Well I needed to make a board this weekend but did not realize that I
> was out of the developer. I use the M G Chemicals 600 series board
> with positive resist. Normally use the M G Chemicals developer which
> is Sodium Hydroxide, but can not get it over the weekend. Never have
> found a place to buy the Sodium Hydroxide without ordering it in.
>
> I tried some Washing Soda but so far it does not seem to do anything
> to the resist. How strong should the washing soda need to be mixed?
> or will the washing soda even work on the M G Chemicals positive resist?
>
> Ben
>