"Rex B" wrote in message
...
DeepDiver wrote:
"Rex B" wrote in message
...

Find some Evaporust.
Dissolves the rust, doesn't hurt finishes.
2 hours max.
Good stuff.

Interesting that you've found it doesn't hurt finishes. According to the
Orison marketing website:

"EVAPO-RUST [is] perfect for removing weapon finishes such as Bluing,
Parkerizing, Zinc Phosphate, and Browning. Blueing and zinc phosphate
coatings (heavy zinc per MIL-DTL-16232 and light zinc per TT-C-490) can
be
removed both at room temperature (@30 minutes) and 118 dergrees
Fahrenheit
(@15 minutes)."

According to them, it eats up finishes (and rather quickly at that)! What
types of finishes have you tried that it didn't damage?

Sorry, I should have said it doesn't hurt good paint. Old paint is another
matter, as it took the paint of a a 1937-ish AA hobby lathe.
As for bluing, since it's basically a form or rust, it makes sense that
it would remove that.
So in this case it might not be what the OP needs.

Does electrolysis remove bluing?


That OP would be me. I was pretty excited (and amazed) when you first stated
that EvapoRust wouldn't hurt finishes (the implication being that it
wouldn't hurt black oxide, since that was the subject of this thread); I
thought perhaps that the chelating reaction was limited only to pure rust.
Oh well...

So now I'm wondering what makes EvapoRust so much better than a bath of
vinegar and salt (besides perhaps the speed of de-rusting)?

Btw, can anyone tell me what is chemically different between rust and black
oxide. I know that black oxide is a more durable oxidation film than rust,
but what makes it adhere to the surface of the steel better? And what makes
it black/blue?

- Michael