Re: citric acid where from ?
Oxalic acid does a nice job on iron stains- the main ingredient in any "rust-away" type material. Also does a lovely job of dissolving nuts, bolts, staples, trim, and many other metal items you do not want dissolved!
Useful, yes! Just use carefully and for the right reason on the right materials.<br /><br />Vinegar indeed works, though a gallon or two of citric acid keeps much longer and works a little better, in my opinion. Less stinky as well. IF you can find the right source it can be cheaper because you pay shipping on a powder packet instead of a gallon of liquid. Photo stop bath is glacial acetic acid, the concentrated version of vinegar. You'd have to figure out a dilution if you use it, though. I used a lot of citric, vinegar and oxalic (and worse acids) cleaning the insides of hemodialysis machines. Citric was my preference because it was not nearly as dangerous as some, but worked very well, was cheaper and stored better than vinegar. Use of eye and hand protection is not optional, IMO.
