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MG MGB Technical - Underbody Protection

Has anybody had any experience with Rust Buster Epoxy Mastic 121? I've been looking for an alternative to the now-departed Shell Ensis fluid, and our US cousins' excellent Rustoleum seems to be unavailable. This seems to be the best alternative. My intention is to use it to preserve my rear leaf springs; everything else is getting Hammerite black instead. Thoughts?
A Riddett

Ask me that again in a few months....
I've just got my GT shell back from being dipped and the next task is to coat the under body with Epoxy Mastic and the top with their Custom Epoxy 421 primer if it would bloody warm up a bit!
Not sure if its flexible enough for springs but I would be interested to find out. I'll give them a call and let you know what they say.

M McAndrew

It certainly sounds impressive.
Dave O'Neill2

I've bought some of this

I don't know whether to use it on the underside of the car or just on springs, axle, crossmember.

My car is black BTW.
Dave O'Neill2

Dave, black is good - I may look at this stuff as an alternative to Hammerite. Thought the mastic might be flexible enough to handle the spring movement and would penetrate sufficiently to deter any further rust from forming between the leaves. Whole thing is getting coated in Kurust as well to finally kill off any rust.
A Riddett

I think that Hammerite is too brittle on its own and would easily chip. I have given mine two coats of Antirust red oxide promer then Hammerite, then sprayed on a couple of coats of stone chip to deflect any road chips. Finally I sprayed waxoyl over the complete underside and Dinitrol into the boxes. So far in the intervening 15 years its been fine and required no further treatment
Iain MacKintosh

"I think that Hammerite is too brittle on its own and would easily chip"

True, I repainted the MG bardge on the front of my rubber bumper V8 with ordinary satin black, but it started chipping off straight away. I then tried Hammerite satin and although it lasted longer it has still chipped.
PaulH Solihull

I have used Epoxy Mastic on my B.

The the underside of one floor was taken back to bare metal, given a wipe with phosphoric acid and and then painted with it.

The other floor was replaced with a new one. The e-coat primer on that was keyed and I then painted it with Epoxy Mastic as well.

In 10 years I will be able to say if it was any good.
David Witham

This thread was discussed between 02/05/2012 and 08/05/2012

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