Rusty46 said: I buy phosphoric acid by the gallon at a local chemical supply. It's a 75% solution, which I'm told is the highest percentage available in WA. I mix 1/2 cup of the 75% solution with 4 cups of water to use to convert rust . I'm using it to aid in removing rust from pitted sheet metal and for storing cleaned metal to prevent rust. One gallon from chemical supply is $15.
The phosphoric acid sold by Tractor Supply Co. (RustBuster)is 25.9% and I forgot to look on the label whether they recommend dilution. I have purchased 75% at a local (KC, MO) supply house and now want to dilute for use.
From Rusty46's statement above I calculate that to be 8%. Is an 8-10% solution normally what is used? I will be doing small parts submerged and sheet metal with spray bottle.
Paul
