powder coat prep

[guiness]

after sand blasting how should i prep my working surface
ready for powder coating
i.e removing blasting dust

for alloy im not to bad

but its rusty parts im having the problem with like old calipers
i seem to have pin holes in the powder coating


heres the alloy seems ok

 

[Premiershipman]

Normally pin holes are caused by the rust gassing out during baking, the only way is to try and get all the rust off completely otherwise you will have problems.

Maybe try the electrolysis method to remove all the rust ?

 

[guiness]

hmm seems that i have been trying to clean the dust off
when the problem is deep pitted holes still contain small pockets of rust

many thanks

 

[graffian]

you could try outgassing, think that's what they call it, I think it's usually done to ali castings. I think all you do is stick the parts in the oven and heat above the cure temp, to allow any gassing to occur, then remove from oven and coat.

 

[guiness]

thanks will try that

shot blast
clean part
back in the oven to degas
allow to cool
then powder coat

 

[graffian]

I have been blowing the grit/dust off and then washing with brake cleaner. I always see dirt when I wash the parts with brake cleaner.