Spray painting brass fire trim

[garrymum]

Hi

I am having problems painting our brass fire trim and fret. I wiped the brass down with white spirit to remove all dirt / grease and allowed it to dry thouroughy. I applied the first coat of matt black BBQ paint and it looked great, a nice even finish. Once dry I applied the second coat and this is where it has all gone wrong. As soon as I sprayed, it seemed to 'craze' in random areas.

I have sanded it all down, cleaned and sprayed again and exactly the same thing has happened again.

Anyone any ideas?

Thank you.

 

[LJW61]

Rub down & wipe/de-grease with cellulose thinners or meths...white spirit will leave a slight oil residue

 

[garrymum]

Rub down & wipe/de-grease with cellulose thinners or meths...white spirit will leave a slight oil residue

I used white spirit to clean the bare brass before applying the first coat and that was great. It was only on the second coat that the "crazing" began. Surely if it was the white spirit that caused the problem, the first coat would have reacted the same way?

 

[LJW61]

Ah,I missed that bit ..
In that case does it state on the can that the second coat has to be applied within a certain time of the previous one?
Some paints such as Hammerite are like this , you must apply the following coat within a few hours or have to wait something like 4 weeks for the first to 'cure'
It does sound like your second coat is reacting with the first..

 

[JohnD]

I wonder if you used a primer?

Paint will not stick well to shiny polished brass, it needs a rough surface.

The second coat might have softened the first coat and you had a swelling/shrinking going on.

 

[garrymum]

I wonder if you used a primer?

Paint will not stick well to shiny polished brass, it needs a rough surface.

The second coat might have softened the first coat and you had a swelling/shrinking going on.

No primer, sprayed the first coat of BBQ paint directly onto the cleaned brass trim and it was a perfect finish. It was the second coat that crazed. I have since tried again 3 or 4 times now - rubbed down and cleaned (last time with thinners) and the same thing has happened everttime. Going to rub down tomorrow and prime the brass first. Anyone recommend a heat resistant primer for brass?

Thanks

 

[joe-90]

it sounds like you are spraying too close and the thinner in the paint is affecting the already painted surface. Hold it back a bit so it's not so wet. I've never had any bother spraying any surface. Is it car paint? It shouldn't be a problem.

 

[Robbie uk]

The thing is with areosols is that they are not thinned by turps anyway. cellulose or acrylic maybe.

 

[garrymum]

I sanded down, cleaned thouroughly and applied a coat of metal primer, yesterday. That has adhered fine to the brass. Just given it a first coat of BBQ paint and it appears to have adhered fine to the primer.

Previously, as soon as I sprayed the BBQ paint you could see the bubbling and crazing.