Should the body bake in the sun before paint?

[FLFrank35]

It was suggested by a Cobra builder's body/paint guy that the fiberglass body should bake in the sun for 30 days before painting. This is to be sure all of the resin is cured, otherwise bubbles/blisters may form under the new paint. Has anyone else heard/done this? If so, I can get a head-start and park it outside while working on the final pre-paint items.

Thanks

[NAZ]

I'm no expert on glass bodies but I did notice some observations that if I build another fiberglass bodied car, would make me want to let the body sit in the sun for several months before I even started the body work.

I left my hot rod body out in the elements for over a year and noticed that it shrunk (or warped) as it was tighter on the chassis than when I fit the body to it. It became narrower so that the doors rubbed the roll cage when closed even though I left 1/4" clearance per side. Also, the trunk lid no longer fit the opening I had fit it to and the curvature no longer matched the body.

That's the only fiberglass bodied car I've built so only one data point.

[FLFrank35]

I'm no expert on glass bodies but I did notice some observations that if I build another fiberglass bodied car, would make me want to let the body sit in the sun for several months before I even started the body work.

I left my hot rod body out in the elements for over a year and noticed that it shrunk (or warped) as it was tighter on the chassis than when I fit the body to it. It became narrower so that the doors rubbed the roll cage when closed even though I left 1/4" clearance per side. Also, the trunk lid no longer fit the opening I had fit it to and the curvature no longer matched the body.

That's the only fiberglass bodied car I've built so only one data point.

Good to know!
Thanks!https://thefactoryfiveforum.com/images/icons/icon14.png

[Presto51]

IMHO This is an "old wives" tale, that gives a cover to someone who didn't to the paint prep right.

How can I think that you may ask?

Well I found when you lay fiberglass up in a mold, you are adding catalyst to the resin, which gives you an set amount of time to apply it. After that amount of time, a chemical reaction occurs, which starts the curing process of the resin mixture. After a set amount of time the resin will finish it's curing, and begin to cool off. Once that happens you can't reheat the resin and finish it's curing process.

Now if there are air pockets, excess clay etc., in the lay up process, and are not discovered and addressed during the paint prep stage, then yes they will show up after everything is painted.

Like I said in the beginning this is IMHO after working on fiberglass cars and boats, and you will find other keyboard warriors that will argue the other point, it's up to you on what and who to believe.

P.S. If you choose to lay the body out in the sun, you won't hurt it, just make sure it's supported.

Ron

[FLFrank35]

IMHO This is an "old wives" tale, that gives a cover to someone who didn't to the paint prep right.

How can I think that you may ask?

Well I found when you lay fiberglass up in a mold, you are adding catalyst to the resin, which gives you an set amount of time to apply it. After that amount of time, a chemical reaction occurs, which starts the curing process of the resin mixture. After a set amount of time the resin will finish it's curing, and begin to cool off. Once that happens you can't reheat the resin and finish it's curing process.

Now if there are air pockets, excess clay etc., in the lay up process, and are not discovered and addressed during the paint prep stage, then yes they will show up after everything is painted.

Like I said in the beginning this is IMHO after working on fiberglass cars and boats, and you will find other keyboard warriors that will argue the other point, it's up to you on what and who to believe.

P.S. If you choose to lay the body out in the sun, you won't hurt it, just make sure it's supported.

Ron

Ok, maybe it was air pockets that were the problem. It sounds like it'll need some sun bathing time before paint.
Great, thanks for the explanation! https://thefactoryfiveforum.com/images/icons/icon14.png

[Chris Wingardh]

IMHO This is an "old wives" tale, that gives a cover to someone who didn't to the paint prep right.

How can I think that you may ask?

Well I found when you lay fiberglass up in a mold, you are adding catalyst to the resin, which gives you an set amount of time to apply it. After that amount of time, a chemical reaction occurs, which starts the curing process of the resin mixture. After a set amount of time the resin will finish it's curing, and begin to cool off. Once that happens you can't reheat the resin and finish it's curing process.

Now if there are air pockets, excess clay etc., in the lay up process, and are not discovered and addressed during the paint prep stage, then yes they will show up after everything is painted.

Like I said in the beginning this is IMHO after working on fiberglass cars and boats, and you will find other keyboard warriors that will argue the other point, it's up to you on what and who to believe.

P.S. If you choose to lay the body out in the sun, you won't hurt it, just make sure it's supported.

Ron

Ron, I agree, after having have had several fiberglass boats.... new and used.... I have never heard of these isuues and yes my latest was a sailboat with painted topsides.

Everyone does their own research i hope. I have a truck coming and I am not going to let it sit outside for any length of time.

Cheers,

Chris

[Ray]

On some of the older bodies it was recommended that you beat the body with a stiff wire brush to pop any voids. You can also take the body into the sun and crawl under it. You should be able to see most of the voids as light spots. But, if you want the best information about body prep etc. you need to talk with Jeff "Batman" Miller (http://jmillercustoms.com)

Ray

[cob427sc]

I have built 7 FFR cars of various models and several other fiberglass bodied cars in which I did all my on paint and bodywork. None were left out in the sun and none ever had problems after paint.