Clearcoat Failure Questions for the Meguiars Pro's

[onawrxhigh]

Hey everyone,

I have a 1999 Metalic green Ford F-150. Today after I was checking out a bird bomb on the upper door (above and around the drivers side glass) what appears to be clearcoat failure on the roof of my truck. The paint is cloudy/milky looking and is not yet flaking off. I read Mike P's thread
http://meguiarsonline.com/forums/sho...arcoat+failure
It looks to me to be from the picture references the beginings of Clearcoat failure. This truck is 10 years old and the roof is the only place I see this happening. I understand that this is only fixable with a repaint but I don't want to have to take it to a body shop just to fix the roofs clear. My main question is if I decide to paint it myself do I need to sand the clear completely off in the affected area and respray with clear or should I sand off the entire roof area then re-clear the entire thing. Again this is on the roof and is not really seen unless you stand on the tube steps or the door sill.Also I know that the gloss comes from the clear but should I buff out the sanding marks before I clear or would it be ok to clear over the sanding marks as the would be in the color coat. Just looking for some advise in this matter. The entire roof is about 4x5 feet and the affected area is about a 2x2 foot area. I was thinking more on the lines of sanding and re-clearing the entire roof area to avoid any possible future failure of the clearcoat. Thanks in advance for any information everyone could provide me with.

Andrew

[Mike Phillips]

Re: Clearcoat Failure Questions for the Meguiars Pro's

My main question is if I decide to paint it myself do I need to sand the clear completely off in the affected area and respray with clear or should I sand off the entire roof area then re-clear the entire thing.

I'm not a painter but I've painted one car in a booth and a couple of paint jobs sprayed in my garage so getting advice from a professional painter would be a better option. There's also painting discussion forums to check out to. That said, if you sand off the clear it will be pretty much impossible to not also sand on the color coat under it and chances are pretty good the color coat will get scratched/sanded/nicked enough that simply re-clearing it won't accomplish the goal, that is it won't look good when you're done.

There's other problem issues with this approach also but suffice to say, if you're going to go to the effort to paint the roof you might as well sand to factory primer and the re-base and the re-clear.

Again, I'm no pro painter so maybe join a auto painting discussion forum and the gurus on that forum will give you up to date information and see you through to success.

[Michael Stoops]

Re: Clearcoat Failure Questions for the Meguiars Pro's

I'm not a pro painter either but I can tell you this: when clear coat fails it fails from the bottom up, not the top down. That is, the bond between the clear coat and color coat fails and spreads from there. That alone would lead me to believe that taking any sort of short cut here would lead to problems down the road. Like Mike Phillips said, you can't just sand off the clear without getting into the color coat so it just sounds logical that a full repaint from primer is the smartest way to go.

[onawrxhigh]

Re: Clearcoat Failure Questions for the Meguiars Pro's

The 2 Mikes,

Thanks for the replys and insite into how best to deal with this problem. I talked to my father today and he even brought up a good question. Doesn't this mean that the hood should start fail soon also? I mean considering that they are the flatest body panel that face all of the elements (rain, snow,ice,fallout,sap,bird bombs,and SUN). Ido not see any signs of failure on the hood. It shines and looks as near to new as a well kept 10 year old trunk can, but the roof is only showing the failure, weird I say. He also stated to me that when I am next out at his place to take it to his cousin's body shop. His cousin is a real perfectionist and has done some amazing paint work on restoration vehicles. I think this is going to be my best bet. Thanks again for both of your insite and advice.


PS Could either of you two recommend a good auto painting discussion forum. Thanks again.

Andrew

[PorscheGuy997]

Re: Clearcoat Failure Questions for the Meguiars Pro's

I have seen a few cars that have clearcoat failure on certain panels. The most common area is the hood, but I have seen the trunk and the top suffer from clearcoat failure.

The process of sanding off the clear and recoating is very difficult. If you sand until you see color in the water, you probably have gone too far. The only good solution would be to purchase a paint gauge that measures each layer ($$$$$). Even then, I would be concerned about the longevity of the paint.

I know of a 550 Spyder that had years of paint sanded off to expose the original paint, but that is an extreme measure and they still had to repaint certain sections.

[Michael Stoops]

Re: Clearcoat Failure Questions for the Meguiars Pro's

I talked to my father today and he even brought up a good question. Doesn't this mean that the hood should start fail soon also?

While that certainly sounds logical, it sort of depends on why the clear started failing on the roof in the first place. Since the failure begins at the bond of the clear and color coats it is possible that an isolated issue caused the failure initially and it just started to spread - once it starts there's no stopping it.

While the problem is usually a more widespread bonding issue, it is possible that the above scenario is playing out. The odds are, however, that the hood will most likely follow suit. Next week, next month, next year..................