Rustoleum Spray paint

[coetzer94]

I have machined mounting brackets for a roof rack project I am working on, and before mounting these brackets to my roof I would like to coat them in a decent quality paint.

I recently bought a can of rustoleum primer spray paint, as well as a semi gloss black rustoleum spray paint. The idea is for the brackets to be permanently fitted to the roof. Will this paint hold up to everyday hammering? Will it easily chip, and form rust? This is a permanent installation, so i do not want to take chances.

I am in Pretoria, so not that much a risk as along the coast, but i often (once a year for 2 weeks) spend time there and don't want them to rust underneath the paint.

[coetzer94]

These are the brackets I am referring to

[Mud Dog]

As far as aerosol spray paints are concerned, Rustoleum is one of the more pricey and better quality ones. I would do two coatings of red oxide etch primer paying particular attention to the edges because this is where surface tension draws the paint away while still fluid. So maybe even 3 coats. Two coats of black enamel overcoat are sufficient.

The brackets are high up so won't get stone chipped and if everything is securely fastened so that there is no chaffing, I cannot see any reason why the paint should not hold up to time.

[pietpetoors]

I would round the sharp edges a bit. Paint dont stick to sharp edges and that is normally where rust start.

If you have a full can just for that I will sommer do 3 layers of each under- and top coat, which 2 or 3 hours drying inbetween.

[Hiluxfan_111]

I agree with Piet. Break those sharp edges.
But I would get those beautiful brackets cadmium plated to stop rust. You can paint them black after if you want.

[Mars]

Or consider having them black passivated then you don't need to paint them and it looks very professional. Cobra Electroplating does that. They are in Kobus Street in Silverton. Pricing is reasonable too.

[coetzer94]

Thanks for the insights. I will tackle those edges with a grinder tonight before using the rustoleum primer I already have. Id rather over do it than have to struggle, so 3 coats primer, and 3 coats semi gloss black it will be.

I will be drilling holes in my roof to fit, any body got tips on how to ensure I have no leaks afterwards? I was thinking along the lines of black silicone/sikaflex underneath and surrounding the bracket where it mounts to the roof. as well as on the fastening plate on the inside of the roof.

[Mud Dog]

Use Sikaflex, not silicone. Also after drilling, first treat the exposed metal edges with a rust converter / inhibitor.

[coetzer94]

Thanks for all the tips. I could not find sika, but found a very helpfull sika rep in builders that indicated another product Stix all. Well we drilled 8 holes per car into 2 vehicles the previous weekend ......so to say that im still in shock is a understatement! We are sorting out the last of the design on the roofrack itself, and it will be sent for lasercutting soon. So hopefully by end of next week I can start to get pictures onhere