quick fix to outgassing

[jazzcornet]

i recently powdercoated a rim in super wet black and i have a very very small amount of outgassing. i did preheat the part for a good 45 minutes at around 300* part temp. i coated and cured for about 35min @ 275 part temp. the cure came out great but there is minimal outgassing that i just dont like. is there an easy way to get rid of it without blasting the entire wheel again? can i just sand down the outgassed part and reheat it for a while then put another coat of powder on it?

quick answers please, i'm kind of in a hurry

[Harleydad]

Yes you can sand and recoat parts. I don't think you need to pre-heat it. Blow off with clean dry air and maybe wipe it down with rubbing alcohol. You may end up having the same issues and need to strip and start over.

For info purposes, I outgas at a temp about 50 degrees higher than the cure temp of the powder. I'm not aware of a powder that cures at 275 degrees, is that a typo?

[woody103]

I always outgas wheels or larger aluminum parts at 450 degrees for at least 40 min. I have tryed sanding and recoating but does not always turn out, may have dull areas or the same out gassing. I use normal old laquer thinner and have the best results with that.

Could you maybe save yourself a headache and wet sand area and then buff it out? or is it more that that

[jazzcornet]

it's very possible that i could wet sand the trouble spots, but imho, that would look like ****. as for the temps. those werent typos. I'm using a curing lamp so it takes quite some time to get a part up to temp

[Spitfire13]

You might want to contact your supplier on that. Just because the powder melts (looks wet) doesn't mean the polymers have fully crosslinked and cured. You could sit at 275 all day but if it takes a min. of 325 or 350 for the polymers to crosslink in a particular powder then you will never get the desired qualities that powder provides.

IMHO.

[jazzcornet]

interesting. i'll keep that in mind

[PCT17522]

Originally Posted by Spitfire13

You might want to contact your supplier on that. Just because the powder melts (looks wet) doesn't mean the polymers have fully crosslinked and cured. You could sit at 275 all day but if it takes a min. of 325 or 350 for the polymers to crosslink in a particular powder then you will never get the desired qualities that powder provides.

IMHO.

That's true. There are low temp curing powders, but if you're not using one of those, then you should use the temp recommended by the supplier to be sure of the crosslink.
There may be an easy solution. Sand the part, and when you spray the second coat use the "outgas forgiving additive". You'd have to order it, and wait for the delivery, and i think that i read somewhere that it might affect the gloss level, but i think this should give you a uniform coating. I have never used the additive personally, but people on this forum are very fond of it. I'm almost surprised that no one suggested this. Maybe there is another issue that i'm overlooking.

[mikmj]

Originally Posted by jazzcornet

i recently powdercoated a rim in super wet black and i have a very very small amount of outgassing. i did preheat the part for a good 45 minutes at around 300* part temp. i coated and cured for about 35min @ 275 part temp. the cure came out great but there is minimal outgassing that i just dont like. is there an easy way to get rid of it without blasting the entire wheel again? can i just sand down the outgassed part and reheat it for a while then put another coat of powder on it?

quick answers please, i'm kind of in a hurry

What kind of metal is the wheel made of


Mike

[jazzcornet]

cast aluminum