What caused this?

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Coyote Jack

Coyote Jack

Member #55, I'm old
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I know this isn't a Mopar, but I don't want to make the same mistake when I paint my Mopars. Two years ago I painted my wife's Murano. It was the typical primer/sealer then base/clear. Everything looked good for a year and then last summer the paint on the roof and hood started to bubble and on the roof the clear even cracked. The sides of the car were only affected to a very minor degree.

When I started to sand the clear off of the roof the paint smelled like fresh paint at times. That could be my imagination though.

I have used the same paint and procedure on other cars and everything is good,

Anybody know what happened?

Jack

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Coyote Jack said:
I know this isn't a Mopar, but I don't want to make the same mistake when I paint my Mopars. Two years ago I painted my wife's Murano. It was the typical primer/sealer then base/clear. Everything looked good for a year and then last summer the paint on the roof and hood started to bubble and on the roof the clear even cracked. The sides of the car were only affected to a very minor degree.

When I started to sand the clear off of the roof the paint smelled like fresh paint at times. That could be my imagination though.

I have used the same paint and procedure on other cars and everything is good,

Anybody know what happened?

Jack

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Was the car covered with a car cover at anytime after a rain or wash and it was still wet. We had a guy cover his car with a car cover in the middle of a rain storm . He rolled the car into his trailer and a little later that is what happened to his car. The guy that sells us the paint said you can not cover a car when it is wet. Mark
 
wow that is really bad.good luck on finding the answer,i hope someone has a answer
 
COUPLE of questions come to mind ! what temp was the area you painted the car, what was the season? if it was summer or cool, the thinner was to slow and never really went off before you cleared it.
 
win38mag said:
COUPLE of questions come to mind ! what temp was the area you painted the car, what was the season? if it was summer or cool, the thinner was to slow and never really went off before you cleared it.
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It was spring and the temp would have been between 60 and 70. The other cars and trucks I have painted all would have been a little warmer.

Jack
 
From what I can see the root cause could be a number of issues.

(1) Primers and top coats have different surface tensions. Did you mix the products? List the types of product and manufacturer of each layer. It's not good to intermix brands. Using the wrong primer such as a lacquer primer with a BC/CC system is a no -no.

(2)Primers vary widely as far as technology goes but all are moisture absorbent - moisture will become trapped in the primer and eventually migrate to the surface after a period of time. Lacquer primer is famous for this and in my professional opinion should never be used.

(3) Failing to allow enough tack time between coats or layers will cause this problem. Do you remember the wait times between layers?

(4) You didn't force dry (bake oven) the paint job I assume???

Answer these questions and I'll try my best to help you find the root cause(s).

sscuda
 
sscuda said:
From what I can see the root cause could be a number of issues.

(1) Primers and top coats have different surface tensions. Did you mix the products? List the types of product and manufacturer of each layer. It's not good to intermix brands. Using the wrong primer such as a lacquer primer with a BC/CC system is a no -no.

(2)Primers vary widely as far as technology goes but all are moisture absorbent - moisture will become trapped in the primer and eventually migrate to the surface after a period of time. Lacquer primer is famous for this and in my professional opinion should never be used.

(3) Failing to allow enough tack time between coats or layers will cause this problem. Do you remember the wait times between layers?

(4) You didn't force dry (bake oven) the paint job I assume???

Answer these questions and I'll try my best to help you find the root cause(s).

sscuda
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The primer and base/clear were all from the same manufacturer and meant to be used together. There was no force drying at any time. This is cheap paint but I have no problems with the other vehicles I have painted with it.

Number 3 could be a problem. I did spray the clear fairly thick and I was in a hurry and may not have waited long enough between coats. I was waiting 10 to 15 minutes. I probably should have waited longer.

Jack
 
Coyote Jack said:
The primer and base/clear were all from the same manufacturer and meant to be used together. There was no force drying at any time. This is cheap paint but I have no problems with the other vehicles I have painted with it.

Number 3 could be a problem. I did spray the clear fairly thick and I was in a hurry and may not have waited long enough between coats. I was waiting 10 to 15 minutes. I probably should have waited longer.

Jack
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Jack,



Not letting the solvent evaporate in the underlying layers will cause this problem. The top layer skins over and traps the solvents. And eventually the trapped solvents weaken the under layers, adhesion fails and viola you have big nasty blisters. If the ambient temperature is a little higher than acceptable the clear will skin over that much quicker.

As may have already figured out stripping the finish and starting over is your only recourse.

I hope I was able to help you in some way.

Good luck with your future refinish efforts.

sscuda.
 
sscuda said:
Jack,



Not letting the solvent evaporate in the underlying layers will cause this problem. The top layer skins over and traps the solvents. And eventually the trapped solvents weaken the under layers, adhesion fails and viola you have big nasty blisters. If the ambient temperature is a little higher than acceptable the clear will skin over that much quicker.

As may have already figured out stripping the finish and starting over is your only recourse.

I hope I was able to help you in some way.

Good luck with your future refinish efforts.

sscuda.
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Thanks sscuda. As you guessed, I have already started stripping the clear off. I am going to repaint the entire car and not be in as much of a hurry. I have also been told to keep the fan on low as the moving air can cause this same problem by making the coat skin over.

Jack
 
Coyote Jack said:
Thanks sscuda. As you guessed, I have already started stripping the clear off. I am going to repaint the entire car and not be in as much of a hurry. I have also been told to keep the fan on low as the moving air can cause this same problem by making the coat skin over.

Jack
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Glad to help out. A little slower reducer in the clear (1% or 2% by volume) helps too. Especially in the warmer weather. Don't sacrifice airflow if you can help it. Wear an appropriate mask too!!!!

I don't envy you having to strip the car but it is what it is.

Good luck with your project.

If you need any pointers PM me.

sscuda
 
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