On Sat, 28 May 2016 16:50:45 -0400, you wrote:
>If you use the Beauty Shop peroxide be aware that the etching is violently exothermic. Lots of heat and fumes. The etching goes very fast. Done in seconds.
I'd be using it to boost the O2 concentration of the etchant, which
hopefully works, since the peroxide by itself I can see as not being
much different from the ammonium persulphate except for the ammonia
ions (and sulphate ions).
In theory, the drugstore peroxide might etch sufficiently by itself,
then the question is either to put a gallon or so of that in, or
refresh it by the beauty shop peroxide.
I'm trying to avoid the CuCl etchant, or at least, the HCL part of it.
Harvey
>
>I use the drug store version mixed 2:1 with muriatic acid from the hardware store. Instead of immersing the board I use a sponge and gently rub the copper. This allows you to control where you need the etching. Obviously, wear gloves.
>
>I'm not sure who first described this technique, but it gives you good control and only takes a few minutes. It also lets you use a very small amount of etchant.
>
>Mark
>
>Sent from my iPhone
>
>> On May 28, 2016, at 2:53 PM, John Ferrell jferrell13@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
>>
>>
>>
>> Read the MDS. It is pretty safe stuff. About a million years ago I was a Lab Tech and HCl was used to wash ink off our hands.
>> Beauty shop peroxide is about 30% and over $30 per gallon. The drug store stuff works and $1 per Qt. I wash all wounds with the $1 peroxide and some people use it for mouth wash.
>> It also leaves bleach dot on you clothing.
>> --
>> John Ferrell W8CCW
>> Julian NC 27283
>> It is better to walk alone,
>> than with a crowd going the wrong direction.
>> --Diane Grant
>>
>>
>>