naval jelly and rust

[jim gossage]

I am using some naval jelly to remove light rust from several cast iron tool tops. I start by brushing a light coat of jelly on the top, let it sit for 5-10 min, scrub with a scotch brite, wipe with a dry rag, and then wipe with a wet rag (instructions say to rinse with fresh water). After wiping with the dry rag the top looks pretty good, but immediately after wiping with the wet rag green splotches appear on the surface that have to be sanded out. It’s clear that the wet rag is messing up the finish. However, I’m afraid that if I don’t use the wet rag some residual jelly will remain and keep etching the surface. Any thoughts on where I’m going wrong? Thanks

[Allen Grenz]

Wd-40 is what I use..

[John Downey]

Try a chelation rust remover instead. HF sells one IIRC, as well as some auto parts stores.

I've even read about how molasses does the same thing :D
Google "home brew rust remover" for articles on that if you're interested.

Personally, I don't worry much about it, but then I live where the air is very dry.

[Leigh Betsch]

I think you need to nuetralize the acid quickly by hitting it with a base or dilute it with plenty of water. Or hose it down with oil. I agree WD40 works well. I say this but in reality I don't use navel jelly. Rather I buy phosphoric acid in gallon jugs at the farm store and just use that. Its cheap and works great. But ya gotta kill the acid quickly or it rusts right back. I usually flush with plenty of water then coat with oil or WD40. In the end the finish is a dark gray, if you leave the acid on a long time it gets close to black.

[Jason White]

You don't need naval jelly for light rust. Just use mineral spirits and a heavy-duty (green) scotch-brite pad. Then, wipe it all off with paper towels and apply paste wax or Slip-It.

[jim gossage]

Thanks guys. Reading between the lines here, it sounds like the discoloration I am seeing is not unexpected with naval jelly. One of the woodworking mags liked Empire Topsaver and didn't mention any problem with discoloration. Anyone use that?

[Steve Rozmiarek]

Navel Jelly will turn nickle plating pink sometimes too. It's nasty stuff, there is usually a better way.