spotty second coat

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sawdust1
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spotty second coat

Post by sawdust1 »

I have a question about putting on a second layer.
I sandblasted aluminum, epoxy first layer, flowed it out. Second layer is polyester clear matt for UV protection. When I applied the second layer I kept getting thin spots like I was looking at a dalmation dog.
Any thoughts?
Not obvious after cooking.

David
weldguy
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Re: spotty second coat

Post by weldguy »

Not sure what would cause that but at least it flowed out and looked good in the end. If you find out let me know because I have had similar issues.
conradestrada
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Re: spotty second coat

Post by conradestrada »

That is caused by a poor ground
ccoatings
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Re: spotty second coat

Post by ccoatings »

Sounds like back ionization, I second the post about poor ground. How close is your ground rod?
sawdust1
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Re: spotty second coat

Post by sawdust1 »

No idea actually!
jessienc
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Re: spotty second coat

Post by jessienc »

back ionization from spraying with the gun to close, its charges little spots in the metal. i started holding the gun farther away and haven't had any issues since
weldguy
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Re: spotty second coat

Post by weldguy »

jessienc wrote: Thu Jun 03, 2021 12:32 am back ionization from spraying with the gun to close, its charges little spots in the metal. i started holding the gun farther away and haven't had any issues since
Thanks for the tip, I will give that a try :Like :Like
adbuch
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Re: spotty second coat

Post by adbuch »

jessienc wrote: Thu Jun 03, 2021 12:32 am back ionization from spraying with the gun to close, its charges little spots in the metal. i started holding the gun farther away and haven't had any issues since
:Like :Like :Like :Like :Like
ccoatings
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Re: spotty second coat

Post by ccoatings »

The issue with BI and the gun being too close would be dependent on the equipment, and I would say that is would hold true for most low end or hobby controllers. For BI, you are most likely looking at a grounding issue on almost all cases. Check your resistance to ground, best with a megger, and go from there.
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