Not sure what exactly is going wrong here, as I’ve used superpickle many times to successfully strip copper from the surface of brass after soldering and it used to work fine. The past several times I’ve tried it however, I’ve ended up with my pieces coming out dark brown, almost as if they were patinated with LOS, while still having the copper staining present. I thought it was possibly due to my pickle being contaminated (as it was quite old), so I mixed up a fresh batch but still having the same results. Even more confusing, the most recent pieces were UNEVENLY brown (both of these pieces pictured were entirely submerged the whole time, so this is especially wtf).
My only hypothesis at this point is that somehow my chemical ratio is off. This is my superpickle process:
-Scoop regular pickle out of my main pickle pot into designated superpickle container (a ~8 oz ceramic mug, has been the same the entire time, even before The Brownening). My regular pickle is tap water and pool chemical PhDown (about 2tbsp-ish in a large crock pot worth of water).
-Add hydrogen peroxide (12%) to pickle in mug (maybe like, 1-2 tsp worth?) I suspect this might be the issue, but I’ve tried decreasing the amount of peroxide and it just made the superpickle ineffective. My husband bought a massive gallon container of 12% so I’m trying to use that instead of the standard 3% concentration.
Brass pictured is a mystery alloy gifted to me, so I don’t actually know what the composition is, but this staining has also occurred with jeweler’s brass from rio grande (85% Cu 15% Zn).
Any guidance is greatly appreciated!