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MG MGB Technical - Naval Jelly

on a forum members' suggestion, I went to buy a random orbital sander to take care of some corrosion around the master cylinder assy area of the engine compartment and was told that Naval Jelly would probably be better than spending $70 on a sander. The guy seemed to know his stuff so I went on his suggestion. has anyone else used naval jelly for similar applications, and if so, success? anything I need to know?
chris

Naval jelly is just phosphoric acid in a jelly consistency.

You still need to remove as much rust as possible before using it as it will only convert a thin layer of residual rust to iron phosphate - a black impervious layer on top of the steel.

I would use a wire brush in an electric drill rather than an orbital sander and buy the cheapest phosphoric acid you can lay your hands on.

Alternatively just use a smooth Hammerite to coat the area which will seal off any residual corrosion and provide a brake fluid resistant surface.
Chris at Octarine Services

You might want to explore a product called POR-15.
Shareef Hassan

aaaah to have por 15, an air compressor, and a paint gun....
Chris

Chris. I would still use the Naval Jelly or a product called "Extend" which is also a "rust deadener" before painting. Most of the various paint type products work by forming a physical barrier between the atmosphere and the rusted metal. This works as long as the barrier is not breeched. If it is, rust can develop under the coated surface and rust can continue. I have seen this with various finishes, including electroless nickel and hard chrome. Kill the rust, then use your POR 15 over it. Les
Les Bengtson

well, three coats of Naval Jelly, at least an hour and a half on the dremel, and an entire morning spent on my MG.... I've got the corner and the master cyl assy primed with krylon rust tough (hey, limited supplies here.... you can all smack me later). this is intended to last only a relatively short while (i.e. over the course of the coming year if all goes well) until I can pull the engine and do a full body respray. stuff has to dry, then I can bolt it back in and test my brake master cyl for leaks.
as for the brake mast. cyl., I took the reservoir off and cleaned everything up, coated the rubber seals wtih vaseline and put it back together. I'm FAIRLY sure that's where it leaked from but I can't be sure. should I plug the outputs with a bolt, fill it with fluid and compress? anyone have a good method for testing before I put the li'l bastard back in?
Chris

Chris, I use a product called Oxisolve from the Eastwood Company to REMOVE all the rust that a grinder won't take off. You can buy it at their website www.eastwoodcompany.com Using any product to paint over or "seal" rust is a temporary fix. The rust will work its way through over time, as it did the first time. Oxisolve is a much stronger version of naval jelly, in a liquid form. You can soak a rag in it and lay it on the rust until it all dissolves. It's reuseable, and leaves a zinc-phosphate finish that is rust resistant for months. There are sections of my car that have had no paint on them for 9 months now, and still are rust free!
Jeff Schlemmer

This thread was discussed on 04/11/2003

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