Cavity wax / painting

[cainhead]

Hello,

 

Finally got back under the car today to continue on my project. I’ve cleaned all the surface rust off and degreased the underside. I’ve got the 3M cavity wax to coat the underneath and also want to paint it to have a clean look. So my question is (excuse me if it sounds stupid), what’s the best process. Should I paint first then apply the wax, or other way round. In my head it was paint first as I was worried the paint would not adhere to the wax but now I’m not sure.

 

Any advice much appreciated

[TheTurtleshead]

In a nutshell paintwork first. You are correct in that the paint won't adhere to a waxed surface.

 

You know that cavity wax is for inside the box sections of the car? Not for coating the underside. I mean you could coat the underside but I'd imagine you'd leave a horrible sticky mess which would attract a coat of dust and dirt in no time.

[cainhead]

In a nutshell paintwork first. You are correct in that the paint won't adhere to a waxed surface.

 

You know that cavity wax is for inside the box sections of the car? Not for coating the underside. I mean you could coat the underside but I'd imagine you'd leave a horrible sticky mess which would attract a coat of dust and dirt in no time.

 

Thanks for the reply. I had it in my head paint first but for some reason starting doubting myself.

 

In terms of the wax/protecting what would you recommend for the exposed underneath.

[TheTurtleshead]

As (it sounds like) you are doing a more restoration style of job.

 

A good epoxy primer (Novol is excellent but expensive). Then a good quality underseal like 3m or Upol Raptor.

 

The main thing is to ensure you are applying it to good, clean metal, trapping surface rust under new products will do it no favours at all!

 

Definitely worth using that cavity wax as a final step once you have finished with the underside restoration. Don't use it before having any paintwork done though as it can interfere with the paint process.

[Nathanj1142]

I've just spent winter re-under-sealing all of my motor. I used the POR15 3 stage rust prevention kit in black. Leaves a nice smooth satin factory finish without having any rubbery/waxy crap for dirt to stick too. Was sceptical at first as thought stones might chip away at it, but I've been over freshly tarmacked roads and nothing as of yet! Dinitrol cavity wax for inside the sills and box sections

[rider]

The Dinitrol 3125 spray (in a aerosol) is a perfect solution to get to all the hard to get to spaces fast. It leaves a high residue corrosion preventing grease film that dries to the touch after a day or so so it won't grab all the dust and dirt if you can leave it that long. I've sprayed this into section, on top of frames and into rails and onto double skin joins. Fast and easy. On painting surfaces then POR paint goes a long way but its very thin so does tend to run or drip annoyingly often. The PRO paint react with air and metal to give a tight bubble wrap type layer. It's strange stuff but being a plastic type polymer it does create a air and water barrier which is what rust needs to feed and grow.

 

If you want to see what is going on with the metal you are covering or treating then the Dinitrol wax will allow you to see any return of rust or rust developing whereas pretty much with any other coating it'll be out of sight and gloriously then also out of mind.