Originally Posted by
unworthy1
I don't know about you all, but I've given up on OA for anything but large-scale soaks where the low cost makes it the best choice. For all my small stuff I'm sold on phosphoric acid: I find it works better, faster, and the "dark deposits" are either not a factor, or I can rub that off with a rag when still wet from the bath. OTOH, almost everything I've soaked in OA gets a light yellowish crust on it that does not rub off. If you have any tried-and-true tips for getting rid of the yellow, I'm all ears.
To me, the yellow is all about concentration. Use it dilute, and don't leave it in for too long. I typically use it at around 0.4% or less, and leave it in for 24 hours or less.