One of my rototillers kept stalling out. Looking inside the gas tank, I could see why.. It had a ton of rust in it so got some stuff off called Evapo-rust. Non toxic, non corrosive, non flamable, no acids or alkali, no fumes, non petroleum, bio degradable and environmentally safe. Had someleft over and tried it on this steelie.
Check the ingredients, I bet it's an acid, probably phosphoric or HCL. Similar to some toilet bowl cleaners.
Sorry, but phosphoric is not particularly volatile and HCl is toxic and both are acids contrary to the description. Being biodegradable, it is some kind of organic.
http://www.pretooling.com.au/media/evapo-rust/EvapoRustFAQ.pdf MSDS http://www.liquidmetals.co.nz/Documents/MSDS%20EVAPO-RUST.pdf
I see it is not an acid. It looks like it works in the pics, i use some stuff called rust-mort on bodywork, it's phosphoric acid and it steams when it hits rust, and boils if you drop it on concrete. It's probably too harsh for coins, in fact, it would probably eat zinc.
Toilet bowl cleaner works great for cleaning inside of dishwashers FYI. Just need to do 3 rinses to get the stuff out after.
Thanks for the MSDS, it is a mild acid and apparently the acid breaks down the iron oxide. It also mentions the detergents. Most detergents tend to be bases so add a little more acid to get that pH down.
