General Heat affects paint

[timgarman]

Hi folks

It's been a while since I posted.

This is a question about engine heat affecting paint on the boot lid, especially around the vents. I've attached some photos which are not great, but show some paint cracking around the vents and also bubbling. This can only be due to heat from the engine.

I'm confident that the original paint job was excellent, although I couldn't tell you what paint was used.

Only 2 other things to mention. I don't have the heat deflector fitted to the inside of the boot lid. But this is so small I'm not sure it would make any difference. I have got one I can fit. Thoughts?

I have the rack and picnic hamper attached to the outside of the boot lid. I wondered if this reduces airflow? Thoughts?

Thanks for your comments in advance. A couple of other pics attached, one of the new aluminium rocker cover and another of the car.

 

[StMarks]

Molto Bella !

As for the paint... I'm not an expert whatsoever, but I have done a bit of paintwork on my own vehicles over the years, and learned mainly from my mistakes.
FWIW your images put me in mind of my earliest attempts. When I did not adequately key the base surface, or did not thoroughly clean back after preparing between coats.
In both scenarios when new the paint sits perfectly over the surface, with a lovely even coat....
.... However,
After a period of time (and heat, perhaps? ) the fact that the new coat is not actually firmly adhered to the layer below allows it to move independently of the panel it is covering. Because the unsecured paint layer and the panel have different density, they can expand and contract at different rates. This leads to the unbonded patches cracking.
I used to suffer most from it in awkward to clean, or difficult to rub down, nooks & crannies..

Like I said, I'm NOT a professional so take it as you will.

Hth.

 

[fiat500]

Your paint damage seems minor in comparison with my car's engine lid. I've twice had to repaint the top coat of cellulose. The undercoat is fine. I have the heat-shield, but my damage is around the right-hand louvres. I'm accepting it as yet another patination that comes with age...much like my own wrinkles.

 

[timgarman]

Your paint damage seems minor in comparison with my car's engine lid. I've twice had to repaint the top coat of cellulose. The undercoat is fine. I have the heat-shield, but my damage is around the right-hand louvres. I'm accepting it as yet another patination that comes with age...much like my own wrinkles.

Thanks Peter.

 

[timgarman]

Molto Bella !

As for the paint... I'm not an expert whatsoever, but I have done a bit of paintwork on my own vehicles over the years, and learned mainly from my mistakes.
FWIW your images put me in mind of my earliest attempts. When I did not adequately key the base surface, or did not thoroughly clean back after preparing between coats.
In both scenarios when new the paint sits perfectly over the surface, with a lovely even coat....
.... However,
After a period of time (and heat, perhaps? ) the fact that the new coat is not actually firmly adhered to the layer below allows it to move independently of the panel it is covering. Because the unsecured paint layer and the panel have different density, they can expand and contract at different rates. This leads to the unbonded patches cracking.
I used to suffer most from it in awkward to clean, or difficult to rub down, nooks & crannies..

Like I said, I'm NOT a professional so take it as you will.

Hth.

Hi and thanks for the detailed response. I'm less of an expert than you but the car was professionally sprayed by someone with a good reputation so I don't have a reason to doubt the quality. The only place that shows any cracking is where it gets hottest, so I've assumed it's pushed the paint beyond what it can cope with.

 

[the hobbler]

Hi and thanks for the detailed response. I'm less of an expert than you but the car was professionally sprayed by someone with a good reputation so I don't have a reason to doubt the quality. The only place that shows any cracking is where it gets hottest, so I've assumed it's pushed the paint beyond what it can cope with.

Hi Tim---I think that there is a fair chance that the fitment of a picnic hamper over the vents will have a detrimental effect on the air-flow through the vents, and therefore allow a build up the heat on these vents.

 

[timgarman]

Hi Tim---I think that there is a fair chance that the fitment of a picnic hamper over the vents will have a detrimental effect on the air-flow through the vents, and therefore allow a build up the heat on these vents.

Thanks Hobbler. I wondered. Maybe I’ll just put it on when she needs to be in full dress gear.