Author Topic: Exterior Paint-Thermal Cracking  (Read 5674 times)

Kurt Schroeder

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Exterior Paint-Thermal Cracking
« on: September 02, 2015, 03:12:00 PM »
The dark color paint on the driver's side of our 2005 coach is exhibiting what has been diagnosed as "thermal cracking" caused by UV exposure.. Although this is a new one on me, research has shown that it is not uncommon among coaches of all brands. Most discussions blame the fiberglass used to build the coach. What is not conclusive is whether the characteristic is simply cosmetic or, if not addressed, will proceed to serious problems requiring the entire wall of the coach to be replaced. Recommendations on the proper way to address it vary considerably. I would appreciate any inputs from current owners.


Edward Buker

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Re: Exterior Paint-Thermal Cracking
« Reply #1 on: September 02, 2015, 07:00:20 PM »
Kurt,

I think in most cases it is not the paint, most all the automotive finishes are very durable with the exception of some peeling clearcoat that sees excessive sun light on our roof edges. I believe that is somewhat driven by inadequate coverage applied there and possibly some prep issues given it is the same clearcoat used on the sidewalls that holds up better.

There has been some reformulation of the resins used for fiberglass and not all of these appear to have been durable. I have a friend with an Allegro Bus that went back to the factory with that issue on a roof and they pulled the whole fiberglass roof panel and replaced it. I have no idea how many coaches they have done that to or how pervasive the problem is.

Unless it causes real problems to the sidewall resulting in delamination issues I would probably live with it, if not trade the coach for another.

In the marine industry fiberglass boat bottoms had the same blistering issue and there have been barrier coats created. The procedure was to sand any paint off to bare gel coat and apply the barrier coat, sand and then apply paint. Whether that process could be applied and then the coach side primed and repainted I am not sure but it would seem likely. It would be an expensive experiment. Perhaps the factory in Red Bay Alabama has more extensive knowledge on the issue and maybe they have a process to repair and reuse those panels they have removed.

Later Ed

Richard McQuillan

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Re: Exterior Paint-Thermal Cracking
« Reply #2 on: September 03, 2015, 06:06:46 AM »
I think I have the same problem...checking or cracking of dark colored (dark brown and wine) paint on one side of the coach that gets greater exposure to sunlight. It does not appear to be a problem with the fiberglass or any type of structural problem. The darker colors tend to absorb the sun's energy at a much greater rate than the more refletive lighter colors like light brown and gold.
Dick McQuillan
2004 38' Monterey Huntington

Edward Buker

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Re: Exterior Paint-Thermal Cracking
« Reply #3 on: September 03, 2015, 03:33:56 PM »
Richard,

I was equating this issue with what I had heard about an Allegro problem and possibly some marine issues. If it looks like it is only the surface paint and no issues with the fiberglass substrate then you are probably right.

There are a lot of newer coaches out there with black paint that holds up so maybe there has been reformulation to fix this issue. Maybe a call to the technical support folks at PPG or Sikkens automotive finishes could shed some light. Best to contact the folks who made your paint if you can figure that out. It is rare but sometimes there is a law suit that results in some compensation to refinish paintwork when a significant problem arises.

Later Ed

Bill Sprague

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Re: Exterior Paint-Thermal Cracking
« Reply #4 on: September 03, 2015, 04:12:06 PM »
I think I have the same problem...checking or cracking of dark colored (dark brown and wine) paint on one side of the coach that gets greater exposure to sunlight. It does not appear to be a problem with the fiberglass or any type of structural problem. The darker colors tend to absorb the sun's energy at a much greater rate than the more refletive lighter colors like light brown and gold.
Checked paint was one of the several things that discounted the value of our '04 Monterey when we sold it.  Between the checked paint, some road rash scratches, a number of fogged windows, a deteriorated 3M front mask, foggy headlights and a corner crack in the windshield we took a financial hit.  Of course it didn't help that it was 12 years old and had 122,000 miles on it.  The inside was still spectacular, but that didn't seem to count as much as the outside, the age and mileage. 

Bill Schneider

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Re: Exterior Paint-Thermal Cracking
« Reply #5 on: September 03, 2015, 11:52:13 PM »
I have the same problem on my coach. It was fairly common on late 2003 to 2005 coaches exposed to intense sunlight. It occurred across several manufacturers. I researched it several years back when it started to appear on the sides of my coach. It was diagnosed as a 3M issue with the fiberglass laminate.  I have not observed it on newer coaches beyond those years stated, so they must have developed a solution. Unfortunately, all of us were out of warranty before this showed up on our coach's. Tiffin is probably the one exception in the industry that will correct problems beyond the warranty period
Other than the cosmetic/appearance issue, it has not presented any other problems.
I just keep the coach waxed and it hasn't affected the shine.