Five years ago I bought five pounds of citric acid in powder form. I rinse my brass in it for a few minutes, watching what what’s going on and when I notice a change I wash and rinse them off. I have no idea how strong the solution is, but because I have so much of it, I’m sure I errored on the strong side.
Yesterday I was cleaning up an old barrel and couldn’t get some rust out of some pitting. I decided to try citric acid on it. I have used hydro caloric acid on rusted steel many times, however I never used it on any guns, fearing it would etch the metal too much.
I’ve heard of others using citric acid to remove rust, but it doesn’t seem to doing much for me.
I scrubbed the barrel well with dish detergent rinsed an put it in the acid bath. Could there still be oil mixed with the rust in the pitting keeping the acid from getting to it?
What ratios do you mix powdered acid to water and how long do you soak to remove rust?
Thanks