Question regarding concentration of chemicals

platinum95

Hi,
I'm going to start etching my own PCBs at home, using the HCL and H2o2 etchant from this instructable - http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/

In this tutorial, he uses 2 parts 3% Hydrogen peroxide to 1 part 36% Hydrochloric acid.

I bought Hydrogen peroxide today, but it is 6% instead of 3%.
What can I do to make it the same as the 3%? Can I just use half as much, or do I add water in a 1:1 ratio with the h2o2?
Or is it something completely different?

Thanks

krd

Just dilute it.

There's not that much need for precision in etching.

SOL

If it is 6 in every 100 parts H2O2 and you want it to be 3 in 100, then add in 100 parts
(an equal volume) water and it'll be 6 in 200 which is the same as 3%


So yeah, as you are right to add 1:1 6% H202 and water instead of 3% H202

platinum95

What is the other 94% composed of? Is it just water?

SOL

exactly

platinum95

Great, thanks for the info everyone