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Old 07-10-2020, 07:51 PM
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Verdoro 68 Verdoro 68 is offline
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Default Spray bomb clear coat wrinkling

I've been experimenting with VHT polyurethane wheel paint recently. I put down a 3 coats of graphite paint, which laid down great. After letting it dry for 12 hours I sprayed a light coat of VHT clear on top of it. At this point the base and clear wrinkled.

Any ideas on what could cause this? I have my wheels painted with the graphite, and they look great, I'd like to clear them but maybe I need a different product.

I've never had this issue with the same brand/type of paint before. The graphite can even says to use the clear on top for more protection.



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Old 07-10-2020, 09:11 PM
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That sucks! I think you cleared it too soon (or not soon enough?). What I mean is that I think you could have followed up with the clear after the silver flashed off BUT since you decided to wait VHT recommends waiting 48 hours before recoating for complete cure.
Not sure of the fix. Depends on how much wrinkling and texture the wrinkling surface.
If it’s not too bad wait a couple of days and maybe you can sand out the wrinkles, spot prime and give it another go.

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Old 07-10-2020, 09:29 PM
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It happened on one of my good wheels which I'm now in progress of carefully wet sanding down. Rather than gamble on the others, I've been testing on an old RII. The can says to wait 30 minutes for the base to dry before clearing. I waited 8, 12 and 24 hours on my experiments. Maybe too long between the base and clear coat? I'll try a clear coat within 30 minutes and see what happens.

On the can it says to lay down your coats in three layers 10 minutes apart within an hour. After the initial hour, if you want to recoat it to do so in 7 days. So maybe you either lay the clear down within that 30 minute window or you wait a week?

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Old 07-10-2020, 09:56 PM
1965gp 1965gp is offline
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I’ve never had much luck with spray can clear coats.

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Old 07-10-2020, 10:12 PM
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I can’t remember the last time I had an issue with issue with a spray clear. Not sure what’s up with this stuff. Maybe it’s just finicky.

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Old 07-11-2020, 08:24 AM
dhutton dhutton is offline
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Did you allow adequate flash time between coats of the gray?

Don

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Old 07-11-2020, 11:02 AM
tjs72lemans tjs72lemans is offline
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Obviously the clear wasn't laid down within the window. It's best to do it sooner rather than later.

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Old 07-11-2020, 12:04 PM
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Quote:
Originally Posted by tjs72lemans View Post
Obviously the clear wasn't laid down within the window. It's best to do it sooner rather than later.
Looks like you're the winner.

I did another test where I laid the clear over the grey 30 minutes after the third coat and it went on just fine.

Came back this morning and put the clear over another section of grey I sprayed last night and it wrinkled. I would have figured more time to cure would have helped but it's clear you've got to follow the instructions in detail for this stuff.

Now the question is what do I do with the wheels I've already sprayed grey? Put another coat of grey on and lay the clear on top after 30 minutes?

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Old 07-11-2020, 07:50 PM
tjs72lemans tjs72lemans is offline
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When it wrinkles, it lost it's adhesion to the mother surface. If it were me, I'd be blasting clean and re-prime, paint. It'll just come off in short time otherwise.

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Old 07-12-2020, 03:18 PM
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I stripped down the one that wrinkled and am starting from scratch. However I have three other wheels I’d like to clear coat that have base coat on them. They’ve been sitting for a week, so I’m thinking the best way to do that would be to scuff and spray another base coat then spray the clear within the 30 minute window. Any risk in that logic?

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Old 07-12-2020, 04:16 PM
PontiacJim1959 PontiacJim1959 is offline
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Quote:
Originally Posted by Verdoro 68 View Post
I stripped down the one that wrinkled and am starting from scratch. However I have three other wheels I’d like to clear coat that have base coat on them. They’ve been sitting for a week, so I’m thinking the best way to do that would be to scuff and spray another base coat then spray the clear within the 30 minute window. Any risk in that logic?
Today's paints in spray bomb has been reformulated to meet EPA standards........and suck.

If you sand your base coat and re-spray, there is a chance that the top coat/re-spray will also wrinkle.

Had all kinds of problems myself with the spray bombs, trying different brands and different techniques. Sanding the wrinkled paint and re-applying does not work.

So here is what I found. You can either put all your color coats on back to back OR, let whatever base coat you apply gas out/solvents evaporate and the color coat cure/harden - which seemed to be at least 2-3 weeks depending on outside temps/humidity - then you can spray over. The paint stays "soft" for a long time and that is where the problem comes in and you get the wrinkling. You can wet sand it and see the soft paint ball up/clog the paper.

I would spray my color coat (s) and let dry about 10-15 minutes between colors. If clear coating, again, don't wait, apply in the same time frame. If you let the paint set-up for too long between coats, you get the wrinkling. Laying on the coats close together can lead to a drip or sag, so you have to learn/watch what works best. I put a light coat on first to get things "tacked" up, so don't try to cover the piece with the first spray. Then follow up with the additional coats to cover. I found spraying all at once with all the coats/clear you plan on using is better than waiting 2-3 weeks and going with the next coat.

The best paints will be automotive paints from your automotive paint/body shop supplier. I never had an issue with spray bomb in years past, but the spray bomb today just doesn't seem to cut it. So a different technique has to be used. Did my pulleys and brackets for my engine and had all kinds of issues. Finally figured out the best way after sanding, or stripping, and re-doing a number of times to get the crappy paint to apply smooth.

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Old 07-12-2020, 04:46 PM
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Don't know if this is hillbilly science or not but my general rule of thumb is that if I can smell it, it's still curing.

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Old 07-12-2020, 05:03 PM
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Or you might try what I do and pop them in the oven at 175 degrees for a few hours before you clear coat them. Just make sure your wife isn't home at the time. It sure stinks up the house. My wife wasn't happy. Of course she also wasn't happy when I brought my 389 inside the house to rebuild it either.
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Old 07-12-2020, 05:41 PM
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Did some more experimenting. I figured there’s less risk in laying clear on than a new base coat then clear. I taped off a small area on one the wheels with the base coat that’s been sitting for a week and sprayed clear. No issues.

Tested a bigger area...no issues.

Just finished doing the whole wheel in three coats of clear and it looks good. Seems like you either lay it on right after you spray the base, or wait until the base is fully cured. Any time in between is asking for trouble.

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