Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

I've been using drug store 3% peroxide .... 100 mL mixed with 50 mL hardware store 30% muriactic acid.
I am NO chemist.
Do we have any chemists here that can tell us anything about these mixtures?
Like is it BAD to do 50/50 plus salt ... for any reason?
 

 

I have been getting good results with a 50/50 mix of muratic and 3% Hydrogen Peroxide, and I add table salt to accelerate the etching.

On 11/23/2016 19:30, duwaynes@... [Homebrew_PCBs] wrote:

 

When using muriatic acid and hydrogen peroxide, the etching time mostly depends on the concentration of hydrogen peroxide used.  I usually get 12% peroxide from a beauty supply store.  With this concentration mixed 2 to one with muriatic acid the etch time is around 2 to 3 minutes.  This is a very exothermic reaction, and the solution will get hot very fast..  You really have t o watch closly with this concentration, because it can over etch very quickly.  I usually dilute this down to 6% to get around a 6 minute etch time.  With the 3%  from a drugstore I usually have a 12 to 15 minute etch time.  Peroxide can decrease in concentration after it ages or exposed to air. in a nearly empty container.
DuWayne KV4QB

-- David Martin - NA1MH - Mountain Home, Ar.-----------------------------------------How much longer do I have to wait for 'Hollywood' to leave the U.S.A. ?