I'm a member on the trifive forum, and we use this trick for rust removal, because EVERYTHING on my old bel-air is rusty.....

Its a product that tractor supply carries, only 10% of stores have it, so good luck finding it.

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Milkstone Acid Rinse. Cut it 10 to 1, and this is what is did for my dies that I just purchased for a pipe bender that I got a deal on....


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I let it soak for 24hrs,



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Then rinse/wash your item when you take it out, let dry, then prime with epxoy primer or self etching primer.

Now on parts that I can't soak, it use whats called OSPHO to spray on the part, and work that into the rust.....both products are phosphoric acid based, if you don't rinse them off, it'll leave a protective coating on the part for long bare metal protection if it's out of the weather. Ospho says to leave the white coating on, and prime right over it, but we don't. We re-apply the acid to re-activate the first coat, then wash both coats off.

I'll get more pics of finished dies, but it works!

D Moss

 

And for those big parts that you don't want to soak, or don't have time to let this stuff react, go to the dollar general or whatever store you have close, in the cleaning agent section, there is some toilet bowl cleaner called "the works".

This stuff is agressive, so be SURE to get you some GLOVES, GOGGLES, and possibly a respirator too. Put it on the rust, rub it in, rinse/wash off after it turns black, paint/prime. It's alot faster then the phosphoric acid, I think it is more like a muturic or hydrochloric acid. Just don't leave it on the metal for too long, it'll eat it up.

 

For small/delicate parts, de-rusting with water, baking soda, and an old battery charger is the better method.

http://www.stovebolt.com/techtips/rust/electrolytic_derusting.htm

 

Where do you get that stuff. I have the works, but I like the idea of a less aggresive approach to rust. I agree on the battery charger method too. Learned this while reading about making hyrdogen for a torch.

 

D Moss,

Dang, it must be stout to work at 10%. Fwiw, My TSC has the Dairyland listed for $14 a gallon.

All: if your local store doesn't keep it, Home Depot has a phosphoric acid based concrete cleaner that's pretty stout for $10 ish a gallon.

Muriatic [hydrochloric] is cheaper and much more nasty, but if you use it on limestone [gravel], the limestone should disolve a bit and make it less harmful to the enviroment. Most of it that you might find will be only 30-35%, which is still nasty. Paint stores, masonry related supply places, pool supply etc. Note sure about lowes/HD etc.

Muriatic will also remove the zinc from galvanized sheet metal. I prefer galvanized witgh zinc removed for any "tin" work on a car, as although bare cold rolled is ok, the plain hot rolled stuff out there is really garbage. The galvanized starts out with a better grade of bare steel, probably has more rust inhibitor too. Once the zinc is gone, it'll take paint just fine.

Muriatic doesn't leave a coating, so if the parts will sit for a while, you should oil, them re-clean later before priming. Using hot water /soap for cleanup will help, as hot will evap quicker and be less apt to cause rust. You could also hit it with a soda ash solution to counteract the acid.

Cheap dollar store spray bottles will survive a few hours with muriatic.

Fwiw, afaik, old timey "Navel Jelly" is phosphoric. It's thick and somewhat sticky and will cling to a surface if you need such a thing. Lowe's has it.

The battery charger thing works well, but a bit slow, and a bit of a pia. I'm no chemist, and I suppose lots of stuff will make an electolyte, but I would use the washing soda/soda ash [sodium carbonate], NOT baking soda [sodium bicarbonate] or lye.
Dave

 

Whats wrong with just soaking in plain old white vinegar? Other than the stink, it works great. I have used it on badly rusted bolts that had sat in the dirt for years just to see how well it worked. Cleans down to bare metal after a day or two of soaking, depending on the level of rust. Biodegradeable too,lol.