开云体育

On Fri, 22 Mar 2019 20:31:31 -0400, you wrote:

I found Sally Beauty Supply to be a good source for H2O2. I recall the
"volume" rating is a bit more than 3x the concentration, so "30 Volume"
H2O2 is 10% concentration.

Do be careful, since the drugstore concentration is far less than the
various products available in beauty supply stores.

I'd think that the best use is as follows:

1) build the etchant with drugstore H2O2 and HCL.

2) when desired, top up the mixture with beauty supply H2O2, but in
far less quantity than needed for the initial mixture.

YMMV


Harvey