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Old 09-11-2018, 04:22 PM   #1
racin69z
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Delaminating clear, what to do

I bought a truck that has paint that I am guessing is about 5 years old. The clear on the top of the bedsides is delaminating from the base. Everywhere else seems to be ok. I am wanting to know if I need to sand all the clear off the whole truck, or just sand what is loose off and scuff the rest prior to priming and blocking.

Thanks
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Old 09-11-2018, 09:08 PM   #2
mongocanfly
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Re: Delaminating clear, what to do

Pretty sure you'll have to take it all off...if it's just the bedsides I don't think you'd have to do whole truck removal...just the whole bed...
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Old 09-12-2018, 08:42 PM   #3
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Re: Delaminating clear, what to do

bare metal
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Old 09-12-2018, 11:33 PM   #4
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Re: Delaminating clear, what to do

You certainly don't need to take it to bare metal and you won't likely have to take all the paint off.

What you will need to do is determine if the coating is tightly adhered or not. A pressure washer is a good start as is will peel off a delaminating coating very efficiently. A razor blade will also strip clean the clear coat if it's not sticking, but won't if it is.

Any new coating can stick to a previous coating so long as it's "tightly adhered"... this is the sticky point... (pun intended)

Once you determined that the clear is sticking in areas or not, you'll have to feather edge the areas where the clear is "tightly adhered" to make a smooth surface. You should apply a high build primer and fix any dents or imperfections while you are at this stage since you are painting it anyway. NOTE: Chances are that the entire area that's starting to peel will be a problem for the entire panel so you might just as well sand all the clear coat off to base coat.

I know this sounds like a lot of work, which it is, but new clear won't glue down failing clear.

The reasons the clear is peeling can be many, but in my experience, the base coat was left too long before the clear was applied and therefore, cohesion was not accomplished. (Cohesion is the term for inter-coat adhesion)

Just my 2 cents.
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Old 10-01-2018, 10:35 PM   #5
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Re: Delaminating clear, what to do

I've done this a couple times. What I've noticed is as you sand back the failing clear to a "feather edge" the failing clear will have a noticeable flaky, white edge. You will need to keep sanding back until you don't have that anymore. 180 or 220 grit works good to do that quickly, then 320, then 400 over everything. Then basecoat coverage and blending, then clear te whole panel.
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Old 10-02-2018, 09:23 PM   #6
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Re: Delaminating clear, what to do

When this happened to stock cars back in the eighties, every one of them was stripped to bare metal by GM and the like, this is why. The base doesn't have much UV protection, the clear is doing that. So when the clear fails the UV is breaking down the base too. You don't need to do it where the clear isn't failing, but on that bed, at least where the clear has failed, strip it to bare metal or at least down into the primer and re-prime it.


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Old 10-15-2018, 05:46 PM   #7
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Re: Delaminating clear, what to do

ok let me weigh in[ I'm at 345 lbs], ok enough jokes we may be getting confused on terms here. First of delamination is generally[GM] a paint problem where the paint does fail due to either adhesion problems or failed primer causing the paint to flake off. Those paint jobs did require me[ I was the GM approved body shop in the late 80's up until few years ago when the General shut down lots of dealers. My local dealer could not meet the requirements to do the warranty work and I did. Anyways to get back on track, the paint flaking was termed Delamination . And like I said that needed to be stripped. The other paint /finish fail was a clear coat problem called degradation and it was a clear problem that didn't require stripping but it did need to sand into the base and repaint and clear. So those two conditions often get confused or crosslinked and that is where som misinfo can happen. Test it the way the General made me test to see what is what. Take some green masking tape rub it down on the place that is messed upthen yank it off. does the paint come off or just clear? If it is just clear sand and refinish if it is paint strip and start from bare metal. I can almost still see me scraping off loose paint with a razor blade when I close my eyes real tight. Boy I did two tons of those paint jobs that made almost no money. Good luck and happy sanding
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Old 10-16-2018, 09:39 AM   #8
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Re: Delaminating clear, what to do

You are right, I was thinking of other makes where the clear typically failed, you fired up some memories it was the primer that failed!

But do to same thing as I remember, the paint was so thin that the UV could get through it to break down the primer and then the paint would peel off. We had a dealer nearby that had a full stripping shop. They had a booth where they plastic bead blasted the paint off. One after another, year old cars, painting them complete, wild!

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