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Tiny bubbles

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Tiny bubbles

Post by exceptional » Sun Feb 21, 2016 9:40 pm

I've searched for this topic with no luck. So any advice is appreciated. I'm using FX clear coat on a patina finish. Final results is a clear finish with very tiny bubbles equally spread out over the project. I lay the project in an almost flat position and apply the clear coat in several coats. I get really good coverage but tiny bubbles. Suggestions are appreciated. t

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Re: Tiny bubbles

Post by tylerdjudd12 » Tue Mar 08, 2016 2:28 pm

Not sure what FX clear is, but I use a good automotive clear, and have no problems. Also do you wipe the part before clear? Sometimes solvents can get trapped and create little bubbles in clear. I use that glass cleaner that foams, and it works really well.
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Re: Tiny bubbles

Post by SeanP » Tue Mar 08, 2016 2:41 pm

It's maybe not leaving enough time between coats to let solvents evaporate, I have had that happen wit 2k paint.
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Re: Tiny bubbles

Post by exapprentice » Wed Mar 09, 2016 3:48 am

I have been told in the past when using a clearcoat to always lay down a very light first coat "dry" and leave it until all the solvent flashes off.
Thats so the first coat dosent attack the original coat your coating over :?:
Then when the first "dry" coat has fully flashed off apply another coat but heavier "wet" to the item and additional coats if required
the trick I believe is to make sure that first coat flashes off real quick and seals the surface before it can etch into or attack the original :?:
only a suggestion as I am no expert ;)
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Re: Tiny bubbles

Post by dekoch » Thu Mar 10, 2016 7:03 pm

I agree with exapprentice and SeanP. I have had the same issue in the past and the lighter coat you put on first helps trap oils and such under the paint. I was also told that the oil from metal can cause a reaction with clear coat, so use a cleaner on the metal before you paint I am not sure if this is correct but since I started to spray a light coat on and let it dry for a good time has prevented the bubbles from appearing.

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Re: Tiny bubbles

Post by tnttracy » Fri Mar 11, 2016 11:35 pm

i believe they use a ppg 2k clear. uniform tiny bubbles... sounds like the acid hasn't been completely removed or some other oxidization process hasn't been stopped. be sure the piece has been thoroughly rinsed, blown off with compressed air, and dried. after i blow them 'dry' i hang them by the fireplace till the metal reads room temp then put them on the paint rack and spray away.

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Re: Tiny bubbles

Post by steelfx » Sun Mar 13, 2016 12:13 am

It's 'Solvent Pop'...Nothing to do with the patina or dye ingredients or rinsing.

Just fyi...The Acid Content of Most Water-Based Steel Patinas is less than 1%. Some of the patinas are 0% Acid.

When shooting 2-Part Clear, I use 2 wet coats, about 10-12 mins. apart. If I get in a hurry on the timing, or lay it on too heavy, I'll get the same thing: Bubbles & Blisters...aka solvent pop. Easy to fix, though...let it cure, sand out with 320 or 400, re-shoot. Done.


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Re: Tiny bubbles

Post by tnttracy » Sun Mar 13, 2016 1:28 pm

would the use of a 'fish eye reducer' type product help reduce to potential of solvent pop?

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Re: Tiny bubbles

Post by acourtjester » Sun Mar 13, 2016 4:45 pm

fish eye reducer is to eliminate dust particles (silicone) where the paint to not cover it. The paint will avoid the particle and will look like a fish eye on the surface, look like a dimple when dried. It is not the same you are talking about trapped solvent (bubbles) that is covered by the layer of paint.
Fish eye
Fish eye (Fig. 10) is caused by a contaminant on the surface prior to application of paint. Generally speaking, that contaminant is a light oil (silicon), which has, by whatever means, found its way to the surface of the vehicle. When paint is applied on top of this contaminant, the paint is unable to adhere to the oily surface and a "fish eye crater" is caused.

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