chemical rust removal/treatment

[Dantheman]

I am helping a friend with his 1939 chevy. Lots of rust in the lower parts of the car. I have done some work with other cars, but this one has some large areas of scaled rust. I am not cutting and fabricating every thing, just what's needed. That said, I know there is a lot of experienced guys out there and would appreciate your inpute. I am working on stripping the body bare to start clean. Need to replace lower rockers. I have cut away to find the backing plate is scaled heavy with some small holes. Advise on cutting and replacing this as well or ok to treat and weld new outters back to it.

Thanks, Dan

[DanielC]

I am not sure what you are asking, exactly.

 

Rust is an electrolytic process.  That means you need water, oxygen, and two different metals.  The problem is carbon steel  provides the different metals in the same piece of steel, and what is worse, once rust starts, the rust itself provides a different metal, with an even higher electrolytic voltage.   That is a lot of mumbo-jumbo, this is it simplified.  Once rust has started, it feeds itself, and makes even more rust.

Rust is a real "female dog"

 

Ideally, you clean down to bare shiny metal.  Even into the bottom of rust pits.  If there is a easy way to do this, I sure have not found it. 

 

I have used two process to remove rust.  Electrolysis, and molasses.   Both take time, lots of time.

Electrolysis info here.

http://community.ratsun.net/topic/3012-electrolytic-rust-removal/page-2?hl=electrolysis&do=findComment&comment=718372

 

With molasses, you mix a solution of about 1 part molasses, and 7 to 10 parts water.  Put the parts in the solution, and scrub them in about a week, or more, depending on the temperature.  Repeat if necessary.

[K_trip]

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[king bee66]

whoa, for the price there asking its, its definitely worth trying!  i just wish i could have scrubbed my floor pans with that stuff before i painted it...

[Dantheman]

Thanks guys, I know there is no easy remedy. My hope was to find something to stop action of the rusting. Maybe enough to leave alone.

 

DanielC  I was hoping you would comment as you always have good advise. I guess my question is have you had any luck with products like SEM RUST MORT, or EVAPO RUST, or maybe some thing from POR15. I have used these things on lighter jobs, but volume of damage is more than I have done to date. This is my friends car and budget is priority. I have heard about the molasses, but it sounds like it would need to be in a bath. The parts are large and some are part of the body structure I'm not willing to cut away.

 

K_trip  I like your link, looks like some thing I would like to try.

 

King bee66  what was the price I must have missed it

[MikeRL411]

And then there's Naval Jelly.  Yes. Naval, not Navel!  Smear it on, go away until you remember that you applied it and hose off.  Then prime very soon!  POR or an epoxy primer.

[JoeCool]

I am going to try that UltraOne rust remover! Looks amazing.

[Dguy210]

Most of the non-toxic/non-acid rust removers work by chelation, and have a ph~5 or so to be gentler on skin. The molasses is also a chelation type of rust remover. 

 

Many of these chelation based rust removers also contain a detergent. Some are proprietary, but you can also use EDTA. EDTA is a true chelator and works just a bit slower. It is however a bit cheaper to obtain than the commercial products (EDTA ~$50 a kilogram). EDTA is also sold as a food additive and stabilizer, and a little goes a long way.

 

Citric acid will also remove rust nicely. It lacks the cl- ion and is a weak enough acid that it does not tend to cause hydrogen embrittlement or need extensive neutralizing other than being washed off with water. 

 

Also EDTA and citric acid can be mixed together readily and a detergent added, adjust ph as needed and you have a relatively inexpensive rust remover.

[Dantheman]

Thanks MikeRL41, I have used Naval Jelly also (good stuff).

 

I will have to spend some time on researching this EDTA. Never heard of it. Thanks, Dguy210

[jdub]

Jasco works good too.

[athoose]

http://www.auto-ease.com/cgi/ppcart.pl?details&metal&1201122800&cleaners

 

 

Captain Lee's rust away. 

 

Of all the rust removers I've used this one works really good and quick.  Don't get it on concrete though.  For large body panels just soak a towel with it and lay it on.  Check out the first page of my build thread for an example.