Urethane Clear bubbling

I painted a Revell 69' Yenko Camaro SS for a guy about 3 months ago. I used a resin outlaw scoop from comp resins.

I taped off a design and shot the car with house of kolor paints and cleared the car with Dupont Chromaclear, it was dried in a dehydrator overnight which from what I read is about equiv. to 16 days of drying time.

I polished it out with Tamiya rubbing compound, and waxed it up to really make it shine. Not that urethane really needs any polishing when laid down correctly, but since he was paying, I really took my time on it for him.

The car came out very cool and the clear was hard as a rock by the time I shipped it to him.

Now, three months later, he calls me to tell me that the clear on the hood bubbled by the decals. Well, the decals he is referring to is actually paint that was taped off.

He told me the car had been just sitting on a shelf for the last three months and he just noticed the clear bubbled. He even offers up an explanation that, "it has been humid here lately, I don't know what could have happened?"

being a builder and dealing with paint, I know that chemical reactions happen almost immediately when the uncompatible products first meet.

I can witness to this from the model car junkyard I have in my shop from these types of problems.
He wants me to strip the car and re-paint at no charge.

My questions are:

1: how would you handle this situation?

2: what experience have you had with urethane clear coats and this type of issue, and possibly give me an explanation of what happened here.

I did some tests of my own.

I took a junk body that had been cleared previously with urethane clear, put some laquer thinnner on one side to see if it would bubble.

the results of this test: it dulled the clear down but didn't bubble it

then I took enamel thinner and on another area of the car, did the same thing.

Result: same thing

these thinners were left on the car for approx. 10 mins.

the last thing I did was actually took a lighter to the body and believe it or not, it melted the plastic before it attacked the urethane clear. I was stunned.

I contacted previous customers who have told me that the cars they have bought from me look as they did from the day they bought them and some of these guys have had my built cars for a few years.

Any help would be greatly appreciated
Happy Fathers Day

Did he send you some pictures of the issue? If not, I would request them, tell him that you would like to diagnose the problem before you decide what to do. the paints under the clear may not have completely gassed out before you cleared them. Not sure of the time frame for the bubbles to occur, I would think this would happen before the clear cures, urethane clear is a very hard clear, Its hard to imagine what would have caused it. Some pictures would help!

Unless it is a curbside, the whole car shouldn't need to be repainted. If he hasn't sent or offered to send pictures, I would first assume that it experienced some damage...

http://i37.photobucket.com/albums/e79/designsbydercock/more%20shit/aah6.jpg (http://i37.photobucket.com/albums/e79/designsbydercock/more%20shit/aah6.jpg)

This is a photo of the hood prior to being sold, as you will see, it is free from any orange peel or bubbling

http://i37.photobucket.com/albums/e79/designsbydercock/more%20shit/a886.jpg


This car was sold as a slot car body to a builder, and as such, I don't know the process that a slot car chassis builder uses to build a chassis. A friend did tell me that when soldering and such a builder could use acid flux.

This guy is trying to convince me that I did something wrong in painting that caused the car to bubble three months later while just sitting on the shelf.

What type of primer did you use? I had a similar problem on resin with Tamiya primer. The remainder of the car is fine which is plastic. Might be something in the resin.

I used Duplicolor filler and sealer and have used it successfully on many different types of resin. Most of which are of much inferior quality than Competition Resin IMO

Did you have a problem with the Tamiya primer and Resin months later? or during the application process?

Hey Sixx...I have done several paint applications using your described methods with no results of this ever happening...I might add NICE paint job BTW..But after 3 months it sounds abit fishy to me..That after this kind of time frame it would just POP up for no reason..I'm curious to see some pics of the car that would help as to what it looks like and see if there are any signs of chemical contact..It sounds like you had ample drying time..I'm stumped..Sorry for the NO HELP...Keep us posted!!

I think White97ex's diagnosis sounds right - I've had Tamiya clear "craze" after a few weeks due to differential drying rates, so it's not too hard to imagine what might have happened here. The only way you're going to find out for sure is if you get the car back, or at least some good pics.

Just one thing though - you may be frustrated about the problem, but the guy paid you to do a (good) job. The tone of your post suggests that he's the one being unreasonable.


This guy is trying to convince me that I did something wrong in painting that caused the car to bubble three months later while just sitting on the shelf.

Did you have a problem with the Tamiya primer and Resin months later? or during the application process?
Problem was later. Like the primer let something from the resin gas out into th epaint. Since them I try not to seal the back side of the resin so it can release anything out the unfinished side. Could be just a bad mix on a specific batch of resin also.

I think White97ex's diagnosis sounds right - I've had Tamiya clear "craze" after a few weeks due to differential drying rates, so it's not too hard to imagine what might have happened here. The only way you're going to find out for sure is if you get the car back, or at least some good pics.

Just one thing though - you may be frustrated about the problem, but the guy paid you to do a (good) job. The tone of your post suggests that he's the one being unreasonable.



Well, clearly you didn't even read the title of the post let alone the post, I didn't use Tamiya clear, it is a urethane clear that was gassed out properly.

The reason I've taken so many steps to figure out the problem is because I am interested in rectifying the problem, and not casting blame on anyone.

In the past, I've used Tamiya clear on other projects and I understand the difference between crazing and bubbling, as I said in my original post, I have a model car junkyard of bodies due to just that type of incompatability happening. My experience has been the problem arises shortly after the uncompatible products meet.

Quite a while ago, Andy (MPWR), taught me a valuable lesson about using compatible products, which I always do now.




Modelerone: That does make sense to me about leaving the underside of the resin un primed an unpainted, I do always do that, particularly because the hood was being glued down. I didn't use Tamiya primer on the car, I used Duplicolor. Great suggestion, I certainly appreciate it!

What type of primer did you use? I had a similar problem on resin with Tamiya primer. The remainder of the car is fine which is plastic. Might be something in the resin.


I thought about that possbility also.
I've used comp resins for a number of years now, complete resin bodies, various hoods and scoops, wheels etc. I have not had the problem with Rogers products to date. it really just stumps me what might have happended in this case

try pmíng hakkfan or dangit what is dave's screen name? they can be found in the motorsports forum. They have been using urethane clears for a long time. They may have experienced this problem..

Thanks Russell, I surely do appreciate your help, very much so! I will do that!