What am I doing wrong here

[PC101]

Here is what I'm trying to do, I am coating pieces in chrome powder, then trying to second coat this with a translucent top coat. My attempts at this have been very unsuccesful. I have tried this several ways. such as:

I have coated the base material in chrome, put in oven until part flowed out, then let it cool. after it cooled I tried to coat it with my top coat. the powder did not want to stick to the part evenly, results horribly blotchy.

2nd I tried coating with the chrome powder, curing until it flowed out, removed from oven then while still hot/warm tried coating the part with the topcoat. still powder would not coat evenly, but better than first try. results blotchy

3rd I new this wasn't going to work right from the beginning, but had to try
I coated the base with the chrome, then with out curing, top coated. of course this didn't work like I wanted, But it did come out with a neat marble effect. Results, interesting, but not what I wanted.

What I haven't tried, is coating the base, fully curing, then trying to topcoat.

It seem like when I try to put the top coat on that there is no static charge, or very little charge.

my next attempt will be, as follows. I enlarged the hole that I was hanging the part from, tapped it for threads, put a bolt into, in hopes that I will get a better electrical connection from the ground. Which I hope will increase the static charge.


Any tips or suggestions will be apreciated. Other than the problems putting on a top coat I'm impressed with the way things are turning out.


thanks to all that help

Ron

[DALE]

Your uneven second coat problem sounds like a ground issue. Are you replacing hooks between coats? I coat until flow out then an additional few minutes to be sure flow out is complete then when cold to the touch I recoat. For the second coat I replace the hook and check the hole for powder, also I reduce the voltage by 25%.Then cure at normal temp and time as you would a single coat.

[PC101]

ground issue is what i was thinking, that was the purpose of tapping the hole and using a bolt instead of a hook, that way no powder could get into the hole.
I will try your method. You mentioned that you reduce the voltage by 25% for the second coat. 1) what do you reduce the voltage to since I don't know what your starting voltage is and 2) What does that do for you? just trying to pick as many braincells as I can.

thanks

[DALE]

Reducing the voltage is done to reduce back ionization. This is a bit hard to explain but basically it causes the first coat to repell the second coat.