I think when someone is contemplating using Hydrochloric/Muriatic or even battery acid for rust removal, and this has come up a bunch of times here, they tend to look at acids in the wrong way. There seems to be a misconception that "acid" is a substance in itself instead of being just one of the properties of different chemicals that happen to be acidic, thus the mistaken idea that acid is acid just some acids are stronger than others. Phosphoric acid and Muriatic acid are two different chemicals that affect iron in drastically different ways but because Phosphoric acid removes rust then some get the idea that a stronger acid would work even better. Also that book makes a good point in that the way different acids affect iron has been well known for a heck of a long time and if Muriatic acid or Sulfuric acid (sulfuric acid for rust removal has come up a couple of times) were a good choice for rust removal they would be popular for that use, they are not.
Last edited by oldred; 02-22-2008 at 05:00 AM.