I seem to be getting some “Fish Eyes” in my powder. This has happened two times in a row with slightly different prep process. I am using PBTP Wheel Silver II. This is actually the second time I have coated these wheels in the past couple of weeks. The first time, I didn’t experience the fish eyes. I decided to start over with the wheels due to some flaws and not flowing out well (old powder combined with inexperience).
First time process:
- Strip wheel with aircraft stripper
- Rinse with water
- Outgass @ 450 for 1 1/2 hrs
- Sandblast with black diamond (new)
- Rinse with water and bake at 200 deg for ~ 15 mins to dry
- Rinse with denatured alcohol
- Coat
- Bake @ 400 deg
I thought that the “fish eyes” may have been from residual stripper or rinsing with water after blasting leaching out. So I modified the process the next time.
Second time process:
- Strip wheel with aircraft stripper
- Wash with diluted Purple Power
- Rinse with water
- Outgass @ 450 for 1 1/2 hrs
- Sandblast with black diamond
- Rinse with denatured alcohol
- Coat
- Bake @ 400 deg
I had the same “fish eye” result the second time.
My equipment is an original Hotcoat gun with fluidizer attachment. I am running the air through 2 standard filters, a coalescing filter, a desiccant filter, regulator at gun and gun filter. I can’t imagine at this point I am getting either moisture or oil through the gun. I sprayed air on a white sheet of paper and it is dry an clean.
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