New paint bubbling from heat.

[Gingerbread Man]

Just rebuilt my car. Went for a run. Pulled over at a point during the run and noticed this! Seems the paint job is wrecked. Newly sprayed ~8 months ago and then it's sat in a garage being rebuilt. First time out on the road.

What has caused this? It looks like a vinyl wrap with air still stuck under it to describe it well. I also notice the paint is very soft. Fitting the nosecone seems to have chipped the paint at the slightest contact with the body.

Bit gutted really as it needs to be in a shipping container for late October!

[Gingerbread Man]

It's Kawasaki lime green. I believe he said it was water based.

[Gingerbread Man]

I plan to Monday morning. Paint seems soft in other areas, easily chipping.

[Gingerbread Man]

trickywoo said:

Maybe a paint fault but lack of heat shielding on the exhaust isn't going to help.

I'd wrap the exhaust or get them ceramic coated.

Bit late now but some heat shielding on the body work would also do the job if look more unsightly than wrapping or coating the 'zorst.

The thing is that every other Caterham, and mine since 1999 has been fine like that, so something's a miss.

[Gingerbread Man]

Not as yet. MOTed it yesterday, will hopefully get it to them this week. The nosecone is still to be painted, so needs some work either way.

[Gingerbread Man]

It's hopefully going in for Wednesday.

I delivered a bare ally (newly repaneled) chassis to him. The scuttle and bonnet had need paint stripped by me, they were reused in their then newly bare ally finish.

How should be have gone from this to paint to ready to hand to customer. What are the stages, oven bake? Etch primer?

Just so I have a better understanding,

Thanks.

[Gingerbread Man]

7even said:

Generally fibre glass isn't baked as it tends to cause more problems than it cures... pardon the pun.

Caterham are aluminium skinned.

[Gingerbread Man]

Squiggs said:

Etch prime
Prime (there maybe a quick bake at this stage)
Then either direct gloss or paint and lacquer.
Full bake.
Obviously there are prep stages between all of those.

It could be that etch wasn't applied but prep is more likely the problem.
If the sanding stages - either on the bare skin or on the primers - was too smooth it means key for the following stages is to fine and the next coat has nothing to grip onto.

I would hope that the painter would investigate as I'm sure he would like to know what's gone wrong.

I find the paint to easily chip, soft as it were. Would this say anything about the paint?

[Gingerbread Man]

Not too sure other than I believe it to be water based paint. That's as far as my knowledge goes at mo. I was meant to take it down tonight,but having had my day dragged on, hopefully tomorrow now.

It was painted around April this year I think, my memory goes.

[Gingerbread Man]

Right, turns out it's not water based. The lad said it was 2 pack. Kept going on about heat shields. They look wk, I'm not having one, it was never an issue prior, research the issue and sort was my point I hopefully got across.

Fingers crossed.

[Gingerbread Man]

I disagree. All Caterhams have no heat shields on the exhaust primaries as they exit the car. The only place where heat shields can be attached are around the can to help protect people exiting and entering the car, not for the paint work, they only sit on the top aspect, not between the paint.

Some wrap the exhaust primaries to remove heat from the engine bay to get a cooler bay/ engine temps. The wrap normally stops as it exits the side skin. Some say this pushes the heater further down the can. A.k.a. out of under the bonnet and nearer the outer skin.

The exhaust gap to aluminium side skin is standard, not uber close to it. The engines a badically standard 1.8 in a mild tune, not really working for it's living.

No mention of this issue that I can find on the Lotus Seven Clubs website. This takes me to believe that it's not a typical issue.
The paint from it's original spray in 1999 up until the respray ~8 months ago was fine. Seemed harder, didn't really chip. The car was used as a daily, in traffic, long drives. It's been on track. Now the paint seems to chip easily. The paints bubbled under the typical heat of a Caterham, nothing unheard of.

This seems a one off, paint issues now when not before. Meant to be the same type of paint, should be similar in its properties.

A suggestion of a paint shield seems to be an easy way out to solve an issue which they seemingly don't want to find the source of! Which there must be one, an underlying difference from before.

Probably be the only Caterham with a heat shield if it had one.

So I don't think I'm being unreasonable trying to find the background to why it's occurred this time over every other Caterham. The heats caused it I agree, but the heat hasn't seemed to have grown in it's intensity, so the paint seems to have reacted when typically it wouldn't have, and seemily typically doesn't.


If it was a documented issue which I was being fussy about, fair game, but being a one off, I don't see why I should accept it.

Each to their own opinion, but that's mine. I like to know the reasons for an issue, not a cheap easy fix to hide an underlying fault.

[Gingerbread Man]

226bhp said:

Are the affected panels the ones which you paint stripped by any chance?

Brand new aluminium panels. Straight from panelers to painters.

[Gingerbread Man]

Paint isn't an area I know. But I know when an answer is more of a work around, rather than solving the issue at source.

I'm just hoping for the best and that I don't find myself having to respray any time soon.

I'm thankful for the responses. I'm not trying to come across 'chucking my toys out of the pram' and not taking professional advice, when maybe I should.

Different situation I guess, but if I put a blow torch on a copper pipe covered in paint it tends to form many smaller bubbles, or just softens.
If I put it near skirting, sometimes glossed skirting can cause a big bubble. Generally I'd have thought if it wasn't keyed in properly. Should it be able to lift away in a big patch/ bubble as such? I never popped one to see if it was top coat or the lot lifting. Surely it should all be keyed to each layer, effectively becoming one?

The lads are nice chaps, I just hope it goes well as I don't have time, neither do I want to have to sort it out again.

Hopefully I'll know next week.


Someone heat up a painted panel for me as an experiment...big bubbles? What lifts?

[Gingerbread Man]

Can you not tell all of that from the photo!!!?

[Gingerbread Man]

A rep from the paint supplier is popping out to see it tomorrow. Hopefully an answer.

[Gingerbread Man]

civicduty said:

It's now three days later so any word?

Rung the rep who made a special trip out to see it at late notice. The garage owner (who sprayed it) wasn't in when he turned up, so he's only seen the paint bubbling top layer. He thinks it's down to the primer, but he's going back Monday to hopefully take a few layers off and investigate further.

[Gingerbread Man]

civicduty said:

Well at least someone is interested in solving the issue then! How are you looking for it being shipped at the end of the month? Do the people who did the work have any consideration for this?

In a container on the 27th. I made this point quite strongly to the paint company who sent someone out for the next day. The sprayer I'm not quite sure on their turn around times.

[Gingerbread Man]

potato muncher said:

Car manufacturers use different paints and lacquers to those used in body shops. They are then baked at a far higher temperature than we can in our spray ovens and when we do bake them it will still take months to fully cure if ever it does.
The aftermarket products will blister with that level of heat as they are not designed for it.

No other resprayed Caterham does. No reported stories anywhere I can find. Never seen. Never heard from people who race them. No heat guards on any seven.
Basically.

[Gingerbread Man]

Paint rep got back to me today. He said something along the lines of;

"The primer on the panel is sound, it appears that there maybe solvent trapped between the topcoat and primer causing it to bubble, but to be 100%, I can't determine the exact problem. Should be fine if they repaint it. Shouldn't need a heat shield, but this could be an answer if it happens again."

So they're repainting it. Either way, there won't be time to sort out any issues. They're not interested in dismantling it for spraying the one side, so I'm having to source the skills of a great Caterham chap on here to have it dismantled and rebuilt. I think only the rear wing, front wing and front assembly need to come off.

[Gingerbread Man]

Foz82 said:

Gingerbreadman you are rite in saying this shouldn't of happened, yes paint does bubble when it gets really really hot but the new paint should of performed the same as the original. I would be very careful as to how they go from here. If there was an issue between the primer and topcoat then it will still exist and they will just overpaint it, i would want it stripping or sanding back down and redoing. Good luck and i hope it gets sorted

Haha you're the first person to agree with me with your first post. It's ready for collection (Friday), I'm picking it up Monday. It's roughly an hours drive home, let's see how the paint looks when I pull onto home turf.....