Powder Coating over outgassed powder coat

[sfrydaddy7]

After wasting about 7 hours today outgassing aluminum rims they still outgassed on me. Is it possible to wet sand the powder coat with some 400 grit & then recoat using the outgassing additive, or do the need to be blasted again? Would like to stay away from the sand blasting because I polished the lip. I think that's what screwed me because I let the rims cool down so I could mask off the polished lip. Didn't think it would outgass properly with the HH tape over it.

[TurboRoadster]

After wasting about 7 hours today outgassing aluminum rims they still outgassed on me. Is it possible to wet sand the powder coat with some 400 grit & then recoat using the outgassing additive, or do the need to be blasted again? Would like to stay away from the sand blasting because I polished the lip. I think that's what screwed me because I let the rims cool down so I could mask off the polished lip. Didn't think it would outgass properly with the HH tape over it.

sounds like you have something else going on, 7 hrs baking for out gassing??
yes, you can wet sand powder and layer over if your gun is strong enough.
but then you start dealing with "fat" looking powder instead of crisp and clean. sand well young jedi and all will be well, good luck.

[Harleydad]

After wasting about 7 hours today outgassing aluminum rims they still outgassed on me. Is it possible to wet sand the powder coat with some 400 grit & then recoat using the outgassing additive, or do the need to be blasted again? Would like to stay away from the sand blasting because I polished the lip. I think that's what screwed me because I let the rims cool down so I could mask off the polished lip. Didn't think it would outgass properly with the HH tape over it.

I also wonder if it's actually outgassing, got pics? How did prep these wheels? Are these cast rims?

I assume you polished the lip before outgassing. Did you clean to remove all the polishing compounds before outgassing?

You could sand and recoat, but if it truly is outgassing it may do it again. The OGF additive will help, but follow the instructions carefully. Too much additive will result in a waxy appearance. Also be aware that will lose about 10 gloss units using it, i.e. 90 degree gloss will appear to be an 80 degree gloss.

[sfrydaddy7]

I only have a kitchen oven so I had to do each rim one at a time. Our gun is weak worried about second coats.

[sfrydaddy7]

I found Powder By The Pound has OGF black premixed went ahead & ordered a pound. Preped the rims with an acetone and a clean brand new brush. I don't think there cast, have befor pics under aluminum or magnesium post. Was very thorough in clean and prep. Did gel coat & fiberglass for 13 years so I am very anal about my work area, prep, masking, and finished part. I plan on clearing over the black and polished lip, will that bring the gloss back up? Oh, I'll try to get pics up today, rims are at the shop.

[SCOTTRODS]

if they're not cast, they have to be Forged wheels then....the issues you're having do not make sense to me. I think from the bits and pieces we're reading.... you have prep down ok for the most part. Maybe give us some detail on the prep steps. You polished them first right? then outgassed? or vice versa? If you polished them after the outgassing stage,... I bet you have polish contaminants..... if not, I'm stumped....

[baz]

those wheels are not forged they are definitly cast and very porous casting , some of those wheels were magnesium and some were aluminium . i have had a few sets of those to polish over the years and ALL of them were porous , the best of them ended up with many tiny holes in the casting while the worst ones ended up with thousand of craters and pin holes

[Blazin_Jason]

I've yet to be able to eliminate outgassing and the issues it creates, I just do the best I can to minimize it. I've found that sanding the bubbles and re-coating doesn't yield the best results. I usually don't sand down the bad areas since it just comes back. For wheels I sandblast, iron phosphate (if you can), heat up to about cure temp, bring it out and let it cool slightly and hit it with the first coat, then back into the oven to about 300°, bring out and depending on the gassing either do hot, or let cool again slightly and coat. The biggest issues I've come across is corrosion and the powder. For the first coat I use a low gloss powder. You could use a primer or any other AOG powder. I find as long as it's not a full gloss it makes a huge difference.

[sfrydaddy7]

Here are the rims I'm having trouble with. They look pimp standing back but not so good up. Maybe it is what it is & I just being anal but that's how I roll. Super Wet Black sandblasted forged aluminum rims. Those specks are the pits not metal flake. The flash make it look like that. Hard to get a good pic of the pits.

[sfrydaddy7]

More pics.