Striker - 27-11-2023 at 16:56
I'm washing some small copper parts in an ultrasonic cleaner using Simple Green Extreme in preparation for adhesive bonding . They seem clean and free
of the corrosion they take-on from standard Simple Green (the Extreme has a corrosion inhibitor), but I'd like to also remove the corrosion that's
already there from the parts having sit in open atmosphere for a while.
Is there an additive I can throw into the tank to strip the surface oxides for a brighter finish?
If these were larger parts, I'd do it electrically, but they're too small and numerous for that.
This product (https://iultrasonic.com/elma-tec-clean-a2-ultrasonic-solutio...) says it uses ammonia for this purpose, and I've seen others recommend NaCl and/or
acetic/citric acid, but I'm not so sure those wouldn't do more to the parts that just remove existing corrosion (maybe use a sacrificial anode to keep
them from harming the underlying copper?) What about something alkaline like NaOH?
There's also the matter of what's compatible with the degreasing detergents in the solution.
Any thoughts on the matter from those of you who have a deeper technical understanding of the chemistry at play?
averageaussie - 27-11-2023 at 17:40
The corrosion is likely to be carbonate or oxide buildup, considering you have left it out in the open.
Wash the copper pieces in plenty of clean water (tap water should do), and place them in a dilute HCl bath. Any oxide or carbonate buildup will form
copper chloride, which is very soluble in water. Don't use nitric acid, as it can attack copper metal depending on the concentration.
replenish the bath as you need to, and they should be clean after a while. wash the copper off with water once they are clean.
If you want to recover the water, just add a pinch table salt and some aluminium foil, you should be able to recover it.
cleaning them electrically should be possible, but I am not overly sure on the procedure for that.
Thanks, Average.
Striker - 28-11-2023 at 07:07
Smart way to make it soluable. Thanks.
Sulaiman - 28-11-2023 at 07:21
When I was working, we used this
https://electrolube.com/product/swa-safewash-2000/
to wash electronics assemblies.
It cleans copper really well.