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kmac530
09-23-2011, 10:28 PM
I bought some naval jelly and some spray on rust converter for small parts and what not.

I am curious if anyone knows if it is safe to use on spring steel? Things like the leafs springs and carberator or brake return springs.

Im feeling like it could be bad especially on small, thin springs because the rust has already etched into the metal and now the converter I think etches into that so there may be considerable thinning of the spring material and weakening of the spring, not only in strength but also in spring action. Correct?

But how about on bigger heavier spring like leaf springs? Thick enough not to matter much?

mbstude
09-23-2011, 10:50 PM
I'm a fan of Ospho. Available at most hardware stores. I had a '51 door handle that was completely rusted up. I let it soak in the Ospho overnight, and the next day it was perfect bare metal. Amazing stuff.

Skip Lackie
09-24-2011, 07:42 AM
Nearly all of these products are just phosphoric acid, which is relatively benign. It does dissolve ferric oxide (rust) but does not attack the underlying metal to any significant degree. That said, you should not leave it on any longer than necessary to remove the rust, as it eventually will begin etching the iron in the steel as well. It should not weaken any steel if used properly, as the only thing it will remove is the rust.

woodysrods
09-24-2011, 10:45 AM
Beedblast cabinet or sandblasting is the best way to deal with rust!
Good Roads
Brian

jclary
09-24-2011, 11:14 AM
Beedblast cabinet or sandblasting is the best way to deal with rust!
Good Roads
Brian

You have a good point here, and I agree as long as the part is accessible to be placed in a cabinet. However, how about areas that are hard to get to. Like the inside lower door panels, boxed in "A" pillars, etc.

Rust is the bane of any restorer and a never-ending battle. What we are discussing here are actually different products. You can have a "Rust Remover" that is not a rust inhibitor. A "Rust Converter" is a chemical that must have some rust present to work properly. What happens with a "Rust Converter" is a chemical reaction that "converts" rust to a "Polymer" compound that produces a "Rust-inhibiting" coating. Anything that coats metal and prevents oxygen from coming into contact is a "rust inhibitor." Therefore, a simple coat of paint is a rust inhibitor until it begins to break down.

Over thirty years ago, I had an old highly skilled restorer to confide to me that in addition to sandblasting, and blowing paint into hard to reach areas such as inside door panels, he also smeared in thick old stringy styled bearing grease. Anything to keep moisture and oxygen from getting to the bare metal substrate.

It was once a rule that you always applied body filler to bare metal. However, with the invention of catalyzed epoxy primers...it is now recommended to use the epoxy primer first and then apply body filler. The reason for this is that the epoxy primer will seal the metal from moisture and increase the adhesion of body filler. This has greatly improved rust inhibition and extended the life of repairs. The one drawback to epoxy primers is that they have poor UV resistance and will break down under extended sunlight exposure. Therefore, epoxy primer needs to have limited exposure to direct sun and the repairs need to be completed in a timely manner and top-coated to preserve the repair.

I have used and sold "Rust Converters," but I am not completely sold on them for longevity. I have seen some of them break down with frequent moisture exposure. I am more in favor of removing as much rust as possible, encapsulating the metal with "rust inhibitors" such as epoxy primers, paint, or flexible under coating products. It is still a never-ending battle.

Champ51
09-24-2011, 03:45 PM
For parts which can be submerged, I have had great success with electrolysis. Parts will come out of the bath much cleaner than when I used to use naval jelly. And, the bath water with the Washing Soda is environmentally much friendlier and its reusable. I've now rigged up a large bath for larger parts and have seen where some have created huge baths for car frames. It just takes more anodes and a larger transformer.

See: http://antique-engines.com/electrol.asp