I wanted to pass this on for anyone using Permatex Rust Treatment.

I cleaned up my brake caliper mounts and used Permatex Rust Treatment on them. This stuff is nowhere near as good as POR-15, but for certain applications I couldn't justify using that for these parts.

Any-Hoo, After letting the parts sit for a couple of weeks I washed them, acetoned them and painted them with the VHT Very High Temp paint. I let them dry for about a week and then proceeded to follow the curing process. On the last step-600 deg. for 30 mins. I went to shut off the stove nd I look at the parts. The paint was all bubbled up. Considering the care in preparation and following directions as I did I can only surmise that the rust treatment is what caused the bubbling. I don't know if POR-15 would be the same way.

So, if you use the Permatex don't try to use it for high heat applications.


That is all. Carry on.

 

I'm wondering if the acetone and the paint are not compatible. I know lacquer paint and regular paint thinner don't work together they make cottage cheese looking paint, but enamel paint can be thinned with lacquer thinner. I have a lot of experience with high temp paint. For best results I always use a mix of Dawn dish soap and water in a spray bottle and wipe it down with clean lint free rag. Air dry or a heat gun depending on the temperature were I'm working I have never had this solution cause a problem. I have had problems when using certain chemicals to clean surfaces.

 

I might have tried baking them first, to burn out whatever residue might have been left trapped in the pores of the cast. then painting them, and baking again.

 

Good suggestion. I'll remember this for next time. Like Brian said, might have been chem. compatibility issues.

 

This is the (correct) process when doing powder coating --heat the part first to burn off impurities, coat, then put the part back in the oven to cure the powder coating.

If you get a powder coated part that starts flaking off, chances are, in the interest of cutting costs, they skipped this preliminary step and you now have an inferior finish that didn't fully adhere to the part.