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MG MGB Technical - Hammerite Paint Problems

Anyone know of a primer I can spray over hammerite rust-buster paint. All the differing primers have just wrinkled up in a reaction with this paint. I do have some barrier coat paint which I have used before, with some success. Just wondering if there was a primer which would work with this product.

For a supposedly 'top end' (- well it's not cheap) product, you'd have thought they would either have put a warning on their paints about the clash with other forms of paint coverings and/or formulated a rust converter which could be primed as normal.

Any thoughts?
IA Jones

Do they have a primer of their own which will work with it?

Alternatively, ask them if they can recommend a primer which will work with their product.
Dave O'Neill 2

If I remember correctly hamerite is enamel base so if you are using any acrylic thinners at all in your primer it will react
What primer are you using
A multi purpouse thinner will react with it even though you can use multi purpouse thinners with enamel-- You need to use enamel thinners in your primer BUT then you are stuck with the same problem with your topcoat reacting to the primer
Where abouts on the car are you painting
Did you spray or brush your hamerite on If you brushed it on you could brush on some two pack primer without thinners

Hamerite, in it's defence is a rust covering paint, it's not really a rust converter to be painted over-----probably the wrong choice of product if you are trying to kill rust and then paint over it
William Revit

Hammerite Special Metals Primer?

Whilst original Hammerite is not for killing rust its No.1 Rust Beater, is and is supposed to kill rust and provide a primer and undercoat all in one go, 'compatible with most top coats'

My advice is don't use it, use this...

best of...

M McAndrew


Thanks Paul, it is the Rust Beater that I used; just couldn't remember the name for this rubbish.

I actually sorted it out a few days ago before I posted, by sanding it down an spraying with barrier coat before spraying again with primer and sanding this coat ready for topcoat. It's the engine bay I'm doing and I think that its pretty much ready now.

I was just wondering: a) Why it was that the reaction took place. That's been answered by William, thanks for that Will. b) Why have something so reactive with most automotive paints for sale for car application without a warning, or at least an explanation of where . I mean it's for sale in places such as Halfords in the UK
IA Jones

Have you contacted Hammerite with what top coat you used? Asking them what top coats it is and isn't compatible with? I'd be looking for my money back. It's funny stuff at the best of times, have you tried using their brush cleaner and thinners? It certainly doesn't dissolve what in the brush, so I don't see how it could mix and thin with the paint for spraying.

Hammerite thinners most certainly does mix with and thin their paint for spraying - I use it extensively.

Cellulose thinners definitely does not mix with Hammerite paints.
Chris at Octarine Services

This thread was discussed between 12/03/2018 and 19/03/2018

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