Technical Evapo-Rust and/or citric acid questions

Someone here had a huge tank of mol***es located outside that he swore by.

 

Last summer we had a 400 gallon tank we soaked parts in mol***es with. Worked well, we left the stuff in for two weeks if medium rusty, and three weeks for really rusty.

Next summer I think we will try citric acid to see how it goes. I’ll be paying attention to this thread to see what ratios you citric guys are using.

 

I have a covered 55 gallon plastic drum in my shop that started about 20% mol***es and water. I broke it down with hot water to start. Yeah it stinks when I open it,even not used I go stir it now n then. I've added water to it twice... since I set it up in mid 2017 (!) and it works as well as it did on day 1. I had an old aquarium pump to bubble it too but that gave up. Set it, forget it, rinse it later. Done, no damage, great for sheetmetal. I had a basket for bolts too but some piece of **** needed it more than me I guess.

 

Mol***es may work best, but unless you live in a rural area, and have a place for a 55 gallon drum of the stuff, what are you going to do? Vinegar has de-rusted everything I've used it on in 30 minutes. Electrolysis works just as well, and is cheaper especially for larger pieces, but requires more set up.

 

Hellfish mentioned electrolysis. Is that where you use a battery charger, baking soda and water. Knew of someone that swore by this derusting method. Then there is this ad that pops up and it's some kind of laser device to remove rust.

 

Reverse electrolysis is my favourite as it takes rust off, period. However it is a “line of sight” method.

 

Well, since PH (acidity) is also an electric function (but on a chemical level), using acid (vinegar/citric etc.) is pretty much the same as reverse electrolysis, but without the hustle.

 

I thought vinegar ate the good metal along with the rust? Evapo-rust & electrolysis don't?

 

You are correct!

Ben

 

How long do you plan on leaving it submerged??

 

I had the body dipped at American Metal Cleaning, small parts in Evapo-rust (some a few weeks when forgot about) so it might help someone decide.