What caused this (see pics)?

[albersondh]

I have PCed two wheels out of my set. The first one came out great. I duplicated the prep/cooking process on the second and it came out like ass (see pics). Prep was done in the following order (all shop air used was double filtered with no oiler and a new hose):

High pressure water silica blasting + paint stripper.
Water wash
High PSI air dry
Touch up any VERY minor missed spots with 150 grit
High PSI air
Brake cleaner, wipe down with clean, new shop towels
Cook for 30min @425
Clean with Acetone
High PSI air dry
Phosphate wash
Water wash
High PSI air
Cook 10min @400
Cool to 160-200 and shoot.

The color used was Black Chrome with a heat/cure of 400@10min. Once sprayed I heated the wheels to 400 which took roughly 8min. Then I started the 10min cycle. The oven fluctuates about 15 deg between 385 and 400 on the high side. The only thing I can think of that I may have done a bit differently is I may have done a thicker coat. I’m hoping to find there is a general consensus on what I did wrong and a simple way to fix the bad areas on the wheel.







- What did I do wrong?
- Can I fix this wheel?
Thanks for any help.

[jdown12]

looks like you didnt outgas enough before coating ?

[tr4dude]

I would also drop the brake cleaner it can leave a residue on the substrate, just use the acetone or denatured alcohol.

[albersondh]

How can I fix this wheel?

Im thinking this is bad orange peel from powder clumping out of the gun (thick powder spots)? The PC gun (Caswell HV gun) seems to work best with minimal powder in the reservoir. It seems to shoot more consistently and without clumping and or spitting out clumps.


Anyways, can I just sand down these bad spots, and re-shoot a thin coat to fix this? I dread the thought of stripping the whole wheel again. It was bad enough with just the OEM paint....

[Harleydad]

Originally Posted by albersondh

How can I fix this wheel?

Im thinking this is bad orange peel from powder clumping out of the gun (thick powder spots)? The PC gun (Caswell HV gun) seems to work best with minimal powder in the reservoir. It seems to shoot more consistently and without clumping and or spitting out clumps.


Anyways, can I just sand down these bad spots, and re-shoot a thin coat to fix this? I dread the thought of stripping the whole wheel again. It was bad enough with just the OEM paint....

You can try it, you've got nothing to lose. I would sand and shoot the whole rim.

[FigureLLC]

black chrome is a transparant, so you'll probably see a color contrast between that and the single coat wheels and the sanded areas. if you're going to blast the wheel clean, use plastic beads to strip the powder.

[Harleydad]

There is a bonded Black Chrome out there thats a solid color metallic and requires a clear. If this is a transparent/candy you need to apply it over chrome, polished metal or apply an x-treme chrome or similar basecoat.

[hjeades]

Originally Posted by FigureLLC

black chrome is a transparant, so you'll probably see a color contrast between that and the single coat wheels and the sanded areas. if you're going to blast the wheel clean, use plastic beads to strip the powder.

Plastic beads? I'm new to this and have never heard of those do they blast better than glass?

[JTW37]

I found out the hard way, that you CAN NOT do a spot repair. You will need to sand the whole thing and then re-shoot. Or strip it completely and re-shoot.