Engine heat causing the paint on the hood to bubble/crack?

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JDNs78FJ40

JDNs78FJ40

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I have put about 1200 miles on my 40 since getting it back from paint and reassembly, (April - November). Light driving around town and from the sniper screen I've seen the water temp get as high as 202 degrees for a few minutes. It normally runs in the 180-190 range. Original 2F engine. About 2 months ago I noticed a spot on the hood where the paint had risen up and it continued to get worse. About a month ago I pushed on one of the bigger spots and it cracked. I Reached out to my paint guy and took him the hood this morning and he said it had to be heat from the engine that was causing this and that is not his fault. He wants to charge me upwards of $1500 to repaint it and add high temp primer to see if that helps and said I should look in to heat barrier on the underside of the hood . Curious if anyone else has had this happen and if that sounds correct? Aside from repainting it is there anything else I should be looking in to? TIA

A6B975ED DF94 4CED 9A3C C84791C54689 1 105 c
 
Z

zerotreedelta

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If it was engine heat, every FJ40 would have that - there was no protection from the factory.

Is that the bare metal or the primer where it's exposed? If it's the primer, then the primer stuck to the hood but the filler/paint didn't stick to the primer...if it's bare metal, then the primer also lifted. Likewise, it would be blistered **more** on the underside paint if it's actually heat related...given you didn't show that, I'm assuming it's not.

Most of the heat is going to be off the exhaust manifold anyway, which is back and offset to the side...that just looks like some funky bodywork down the hoodspear, possibly aggravated by typical hood flex (as they do twist a bit). That paint chip looks pretty thick material wise...hard to say from here, but that just looks like some adhesion issues in how they did the bodywork.

(I've got ~700 miles on my fresh paint, and my hood isn't doing that, fwiw...and I flung the paint in the garage myself as goober that does this for fun.)
 
Skreddy

Skreddy

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202 coolant temp is also not going to translate to 202 hood temp. I would bet it’s a paint issue and he just doesn’t want to cover it. I can’t tell well from the pic but is it bare metal where the paint cracked and peeled or is it primer? Bare metal would mean an issue in primer application, primer showing would mean an issue in color application. Issue being poor prep, poor mix, applied outside of parameters.
An aside, if you have this cracking in this short of time, I’d be looking for more.
 
germaneighter

germaneighter

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I agree with firestopper that 202 does not seem hot enough to do paint damage. And why would it be isolated to the center ridge hump? Looks like poor adhesion that could be from poor prep. Not saying it is....but it could be. Seems more likely than a heat issue. Did that area of the hood have any body filler?
 
3

3_puppies

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X2 on some filler, seems the thickness of the cracking area is thicker than a coat of paint

and if it was heat related, it would seem to be more over the manifolds than in the center
 
JDNs78FJ40

JDNs78FJ40

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If it was engine heat, every FJ40 would have that - there was no protection from the factory.

Is that the bare metal or the primer where it's exposed? If it's the primer, then the primer stuck to the hood but the filler/paint didn't stick to the primer...if it's bare metal, then the primer also lifted. Likewise, it would be blistered **more** on the underside paint if it's actually heat related...given you didn't show that, I'm assuming it's not.

Most of the heat is going to be off the exhaust manifold anyway, which is back and offset to the side...that just looks like some funky bodywork down the hoodspear, possibly aggravated by typical hood flex (as they do twist a bit). That paint chip looks pretty thick material wise...hard to say from here, but that just looks like some adhesion issues in how they did the bodywork.

(I've got ~700 miles on my fresh paint, and my hood isn't doing that, fwiw...and I flung the paint in the garage myself as goober that does this for fun.)
Yes, in one spot the blistering went down to bare metal and in the spot In the picture it was just to the primer. I think everyone on here is spot on and the problem was in the prep, application or combination of both. Either way I’m screwed. The shop that did the work is no longer open and the guy I took it too worked there but now works somewhere else and he technically doesn’t need to do anything…..
 
Z

zerotreedelta

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Ugh...sorry to hear on the shop closed/snafu there on any "warranty" work. :(

Luckily it's just paint, and the hood is an easy reshoot and removable...hopefully you don't find it elsewhere.
 
Mtntopper

Mtntopper

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Yes, in one spot the blistering went down to bare metal and in the spot In the picture it was just to the primer. I think everyone on here is spot on and the problem was in the prep, application or combination of both. Either way I’m screwed. The shop that did the work is no longer open and the guy I took it too worked there but now works somewhere else and he technically doesn’t need to do anything…..
If the shop is no longer open, that seems like your answer right there. Looks like they cut some serious corners to pocket some money on the way out...
 
tornadoalleycruiser

tornadoalleycruiser

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They didn't prep that area after blasting and the epoxy didn't adhere to the high build. Or the high build didn't get sealed and the top coat is coming off. Whole hood will need to be reshot. Not horrible but darn glad i am doing my own body work! i'm not very good at it but if it fails it's on me.. And i have had my share of failures and redo's..
 
bikersmurf

bikersmurf

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X100

202* is nothing.

My exhaust manifolds get hot enough to burn BBQ paint off. I’ve had a couple hoods now that have had all sorts crappy paint on them. Even the paint that the pressure washer blew 1/2 off the truck had no heat problems.

The day the 220* rated, 150 psi air line from the compressor blew… while in line at the Peace Arch crossing. These days guns would come out… back then everyone was just diving for cover.
 
graham5david

graham5david

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Looks like poor primer adhesion. I painted my old 40 myself. And I do remember 1 thing when I was priming the vehicle before paint. After I stripped the 40 to bare metal,, The original primer I purchased would not stick to the hood.. It would literally sit on it and after a few hours turn to powder. It was so strange. I went to the paint shop and bought a better grade primer and never had that issue after. It was almost as if the hood was a different type of metal. He probably doesn't want to re spray it for free.
 

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