Frame Rust Inhibitors

[beez]

I posted this question elsewhere but I wanted to get more opinions... I'm paranoid I guess.

I have recently had my frame repared/replaced... kinda both... I have applied some Eastwood Rust Encapsulator and some Eastwood Chassis black on the frame to keep the rust away. Now I'm concerned about the inside and how to prevent rust there. A while back I bought some Waxoyl with the applicator (before I knew how bad my frame was) and used over half on the frame and body of the car. Now I'm thinking about appying some to this new frame but would like some opinions on the Eastwood Heavy Duty Anti Rust product and how it compares. Since I already have the applicator for the Waxoyl I would only need to purchase a refil but I would need to get the applicator (which uses an air compressor) and the product.

Does anyone have any recommendations for either product? They seem to be very similar but I haven't found any comparisons on the product or the application method.

Thanks for you help!

Adam
73 TR6

 

[JamesWilson]

Some years ago Practical Classics did a product review on similar products. But the magazine is UK based and the products tested were available there, I'm unsure how many would be commonly available in the USA. Reprints are available:

https://www.practicalclassics.co.uk/article/by-id/1530332578/

Two types of rust converters are commonly available. Both employ chemical reactions to neutralize the rust. The first type uses chemistry to remove the rust and employ a mild acid that reacts with the rust, removing it and leaving a surface in which the iron has reacted with a phosphoric acid to yield a rust resistant compound. In this process the rust is removed- dissolved in acid- and all the metal is protected. The second type converts the rust from an active form into an inactive one. The rust is normally a ferrous oxide compound that consists of a single molecule of iron combined with two of oxygen. This oxide is unstable and seeks to combine with more iron, so the rust may then propagate and infect other iron molecules to form oxides with them too. The other converter leaves the rust in place but converts it to a stable form, one that does not further propagate. This approach stops the rust and protects it from further oxidation, but does nothing to protect unaffected areas. I think POR15's Metal Ready is the first type while the Eastwood product may be the second type.

The Waxoyl is a rust preventative and there are alternatives available too. I think the Practical Classic article reviewed these as well.

A general overview on rust prevention:

https://www.advanceautoparts.com/english/youcan/html/res/res20001101rp.html

 

[Bruce Bowker]

Do these cars have a box frame or is it open?
Bruce

 

[beez]

Thanks James! I'll read those articles today!

Bruce, the frames are boxed. I have a good coating on the outside now I'm trying to coat the inside as best I can.

Thanks again!

Adam

 

[sp53]

Hi James your chemical analysis is interesting and follows much of what I have heard in my travels. Perhaps you could clear up a small problem I have in my limited chemistry skills. For example, if I use a product that is designed to be used on cars and the product is phosphoric acid(Rust Mort) do I need to neutralize it with something when I am done, or does it bond at a molecular level and will not damage the metal surface. I am curious because battery acid seems to keep on corroding. Is it because most battery acid is different like hydrochloric acid or something? I guess my question is; Are different acids harmful to metal. It seems to me if you filled the frame channels with the wrong stuff it would make it worse.

George

 

[71tr]

hycrochloric acid is much more powerful than phosphoric acid and will continue to dissolve metal if not thoroughly rinsed. phosphoric acid based products typically complete their chemical reaction within a couple of hours leaving a slightly tacky film and/or water as a byproduct. i would suggest misting or using a spray applicator for the innards of the frame rails.

 

[JamesWilson]

All acids are harmful to metal- some are very corrosive while others are much less damaging. The idea is to use a "mild" one (Both dilute phosphoric and muric acid seem popular for this) that attacks the rust, dissolving it without damaging the stronger uncorroded metal underlying it. I'd recommend using a commercail preparation rather than trying to concoct one yourself- that's asking for trouble in spades!

The acid should then be thoroughly washed off, the surface dried and immediately painted or otherwise protected. I suppose a base (alkaline) solution could be used as the first step in the washing process, though I've not seen an acid supplier recommend it. The encapsulators do bond molecularly and pose no threat, acid does not bond and needs to be removed once its done what was needed, otherwise it will be a problem.

These acid treatments are not suitable (IMHO) for use inside a box section. Its simply not possible to be sure of cleaning all the acid out. In those cases the encapsulating methods seem most suitable, used along with a rust prevenative like Waxoyl. But its very difficult to be sure of compete coverage within such sections- you can't see and the access is very limited.

A recipe for home-made Waxoyl:

https://www.gomog.com/allmorgan37.htm#WAXOYL

There are different types of this stuff available here in the UK. There's a thin version designed for greater penetration of cracks and with what is supposed to be a better capability of penetrating and stopping existing rust, and a heavier kind intended to cover and protect.

For my chassis shown below. I didn't bother with the acid- I used sand blating with an immediate anti-rust primer on the exterior. Once all the welding and painting are done then the insides will be treated with a thin Waxoyl type solution and left for a week or two and then a heavier type applied. Or so I plan....