That¡¯s not necessarily something you want to remove.?
If it¡¯s not rust, it¡¯s likely oil, bluing (which doesn¡¯t have to be blue) or some other rust preventative, some might be the finish left by case hardening, or some combination.?
If it¡¯s rust, use something like Evaporust, but be prepared to treat it with something ?immediately after de-rusting it.
I¡¯d simply clean them with a de-greaser if it¡¯s just gunk accumulation, followed by an oil application.
Basically you don¡¯t want to rush in to produce a shiny finish in case you destroy the protective layer you¡¯re mistaking for rust.
Also if it¡¯s just old and darker but that isn¡¯t affcting the use¡why worry about it?
This is peripheral to lathes I guess, hope it's OK to ask.? Have a couple of items from another lathe that I'm cleaning up and repurposing for my 7x.
I'm guessing you all have seen older bare metal steel tools.? They get darker over time with use if not protected.? I'm guessing some of it is oil, some is dirt and other contaminates, and some is probably a chemical reaction, possibly rust or rust-related.
I know you can brighten most things up by abrasion - sanding/polishing/etc but that removes at least some of the metal.
Are there any chemical treatments that can brighten steel that has darkened over time, or is it a permanent change in the metal?
--?
Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
