On 1/5/22 9:30 pm, Morris Odell wrote:
Hi all,
I've been using the regenerated copper chloride method for etching PCBs for years and have had very good results. One problem I do have though is getting adequate supplies of hydrogen peroxide which I use to give the solution a boost while etching a board. The local pharmacies only sell it in 100 ml bottles of 6% and even then they keep it behind the counter and give you the third degree when you ask for it. I thought I could get larger volumes from a hairdressing supply place but it turned out to mixed into a gel.
However I was at the swimming pool shop yesterday and was surprised to find 1 litre bottles of "chlorine free pool sanitizer" that contains 35% H2O2 and 0.33 g/L of silver nitrate which is 1.9 millimoles/litre. My question is, can this be used instead of pure H2O2? Should I be concerned that the AgNO3 would interfere with the etch or have a detrimental effect on the stock CuCl2 solution that I have built up over the years especially as it would accumulate?
Any advice from someone who knows more chemistry than I can remember from half a century ago would be most welcome.
I just add some HCl every few months to the FeCl, which is by now more like CuCl after 10 yrs of use. The FeCl started as a dilution 1:1 with water.
It uses a fish tank air pump to bubble air for agitation and oxidation.
Keep the tank covered when not in use to prevent corrosion of nearby metals.
