Painting the Chassis

I finally got to the stage of putting some colour on the chassis today since the humidity was low enough at 50%. Although I’ve not been working on the car at every given moment, I have been stripping the chassis down and preparing it for some time now. The old paint on the chassis was nice and smooth but it started showing signs of rust after a while so I decided to use POR15. This meant going right back to bare metal. First apply a metal prep spray which dissolves any rust and leaves a zinc coating. POR15 rust preventative paint is applied over this. POR15 is non-porous, flexible and extremely tough. Over this, POR15 etch primer is applied which bonds very strongly to the rust preventative paint and gives a surface that can be top coated.


Chassis Surface

POR15 can be sprayed but air-fed breathing equipment is needed so the finish isn’t great as it’s brushed on. I’ve done several other items with POR15 and have found that two thinned coats work much better than one thick one. It’s spreads easier and gets in to all the inaccessible areas too plus too much thick paint and it bubbles which it had done a little on the chassis in areas. The poor finish translates through all the layers of paint so I knew I wouldn’t be getting a show room finish on the chassis.

The red I’ve gone for is one of the original colours available at the time, Signal Red. I wasn’t sure what to make of it from photos but I’m really pleased. It’s quite a bit brighter than the old red, less blue. Ratio for the basecoat is 1:1 with thinners. Mixing it up looked awesome…

Mixing Signal Red up 1:1 with thinners

It took about 4 light coats of red to get full coverage although some areas I noticed didn’t get covered afterwards. Each coat has about 10 minutes to “flash off” in between. About 45 minutes later and I applied the lacquer which is UPOL 1K ready for use lacquer. This took about another 4 coats with 10 minutes flash off between each.

The gun I used was a mini 0.8MM tipped HVLP detail gun which proved invaluable for all the tight corners and enclosed areas of the chassis. I adjusted the fan right down to a small spot and adjusted the fluid control down. It worked really well and I could get paint in to most of the areas. Also having the chassis suspended from the garage roof with two winches made it a lot easier to access everywhere.

Sprayed Chassis


I’m quite pleased over all. I think I’ve got pretty good coverage and it should be a pretty tough and long lasting job which is the prime aim. I’m really pleased with the colour. The only place you’ll really see the chassis is under the bonnet and I think it’ll look really good with the contrast of the silver engine.

The only issue I came across was the primer bleeding through the red basecoat when I applied the lacquer. I’m not 100% sure why but I think it was either that the primer wasn’t 100% dry or the basecoat wasn’t 100% dry, could have been a combination of both. It could have simply been that the basecoat and primer weren’t compatible but I think I would have seen the problem all over then. I have a few more suspension parts to paint using this method but the main body of the car will have high build primer beneath the basecoat, hopefully this won’t happen there.

Primer bleed-through

You can’t really notice it that much and where it has occurred will be hidden from view. At least I can learn from this and hopefully avoid it when it comes down to the real bodywork—I want to see my face in that!

Next stages are to get the various suspension parts primed and top coated as well as treat the inside of the chassis with some kind of cavity wax or paint.

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