Posted by Sherman in Idaho [162.158.107.166] on Monday, May 23, 2022 at 20:22:13 :
In Reply to: rust removal posted by Todd Miller [172.70.211.50] on Monday, May 23, 2022 at 13:54:10 :
I electrolytically de-rust all kinds of stuff, including truck parts (also good for de-painting and de-greasing them), builder's hardware (hinges, latches, etc), and even guns (fully disassembled and with the springs removed.
I've never had an issue with the build-up of any black substance. What I do have is a very thin black oxide coating, similar to gun bluing. That's what prevents flash rust on electrolytically de-rusted parts, compared to sand-blasted or acid-pickled parts. It's a good thing. On gun parts, I just wash the part well, rub oil into it, and call it good, without any extra bluing step.
Lately I've tried parkerizing small parts and that's turned out to be easier than I thought. It's not very fast but it doesn't require electricity. Just phosphoric acid and manganese dioxide, dissolved in hot water, and kept hot for a day or so while the parts sit in it and get turned from time to time.
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