Inperfections/Blisters on Bonnet and Boot Lid

[Andy C]

I viewed a vehicle over the weekend - very low milage 1990 SE. The overall body work seemed very clean, even gaps, and no sign of any front end damage or repairs.

However ..

It has some very pronounced "marks" on the bonnet and bootlid .. very obvious but hard to photograph. The lines in the paint, and they are really defined lines that match the areas where the inner composite moulding bonds to the outer, look really bad and are the first thing you notice about that car.

They could be descibed as "looking like someone had painted over rust that was starting to bubble through" or heat, or stress marks. The only other thoughts I had was maybe the bonding bog was a "too hot mix" and cause distortion to the panels which then showed through the paint. My first guess would be a factory manufacture issue, but I can't see how it would have passed any factory QC checks, and it certainly would have been very difficult for the dealer to sell looking that way as a new car. Has anyone ever seen anything similar? .. is this something I should be wary off? .. does it possibly hide a more serious past or present problem?



and no ... thats not me in the miniskirt and leopard skin handbag ... thats the J part of the A&J
A&J

[davidjt]

The first thing that springs to mind is osmosis, which used to be a problem with fibreglass boats; I've never heard of de-lamination on a car before, but what you describe sounds like moisture in between layers and/or gelcoat. Boats would look fine for several years, until the fibreglass appeared to rot: repairable, but only by grinding out the affected areas and patching them. A good fibreglass workshop should be able to do it, if the car is cheap enough to make it worthwhile.

At least on a car it's largely cosmetic - in a yacht you could wind up swimming!

[Gary]

Guess it could show sign of a respray, but I wouldn't be too worried about it.

I must have missed the mini-skirt ??

[DeeAitch]

I've seen this before, typically on the bonnet, boot and hood covers. Lines up with the inner panel joints where double skinned panels get bonded together. Think it was a chemical reaction thing with the paint which got sorted on later cars. Unsightly but possibly a sign of originallity?

[stevo]

im with dave i've seen this on eary cars. the marks show up on areas which have been bonded. its ok.

[TheBard]

I'll second (third) the above two comments... My red 91 has the same osmosis issue, on the rear flanks, and coffin lid. It is very unsightly, and will be leading me to a respray once I find a place I trust and have the cash in hand
I'd check the cars paint seems similar across the whole car (including the imperfections) as any respray/repair work tends not to match the Lotus original in texture!!! (don't ask )
Good luck,
Ian

[delta]

Don't think it's osmosis.

I'm not 100% sure what it is, but.........

We all know that fiberglass scrink a few % when curing, and a addisional few 0/00 over the next mounth(years.?.) I have seen this patern on other cars, and it seems to be that the inner moulding has been bonded to the bonnet to soon after curing, so it almost has been wet-in-wet, and the addisional scrinking hereby affect the outer skin, long after the car has left the factory.

I have repaired this type of shrink on many fiberglass repairs over the years, and the good thing is that a sanding, a filler spray and a new paintcoat cure the problem for good.

[Monty]

Andy

Thats wierd, cause when i was at stoneleigh, was talking to timmo about my stripes, when we was looking at the bonnet then noticed what u describe and is in the same place too Now i`m 99% sure it wasn`t there when i put the stripes on and wonder is it anything to do with the heat in the engine bay

[chris.t]

I've got similar marks on the rear wing - looks really bad. when i bought the car (from new) the marks were not there and have just appeared over time. My car has always been garaged and therefore weathering is not the problem. My car is NMY and the mark has discoloured the paint. The car is going in for a service in the new year and i am going to ask the garage what has caused it and a quote to get it put right. its one thing having a re-spray but i don't want the problem to re-occur.

[Dico]

Andy

Thats wierd, cause when i was at stoneleigh, was talking to timmo about my stripes, when we was looking at the bonnet then noticed what u describe and is in the same place too Now i'm 99% sure it wasn't there when i put the stripes on and wonder is it anything to do with the heat in the engine bay

That because you were looking at it under artificial light (for the first time)

You going to Donny or what numb nuts?

[Fubar1764]

Jeff's got some similar issues with his. It's fairly extensive. I thought it might be glue or something that didn't age at the same pace with the rest of the body. I suspect it's more noticeable in darker colors as well as cars that aren't garaged.

[Sy V]

Most noticeable on originally painted BRG cars - why I don't know. I refer to it as paint slippage (because it appears that the paint skin has slid down the bonnet and congested at certain latitudinal lines), but I'm not implying that this is the real name or the real reason for the appearance.
Pre-last years respray my car was a prime example.
I wouldn't let it put you off.

[DaveT]

Similar problem here folks but shorlty to be rectified?? -when my new hard top is fitted and sprayed. Similar mark also on rear but not as noticable as on the bonnet.

[Dovey]

I have noticed this too, but only on the bonnet. I'm with Monty on this one as I thought it was heat causing blisters. If you get a respray I would apply extra insulation to the bonnet to stop it from coming back. Or have the cooling fans come on earlier. Somehow.

[Leung]

I have similar blisters near the top of both of my doors.At first I thought they were caused by the heat of the reflection from the wing mirrors but now I am not so sure.

[chris.t]

i think that this is a chemical problem rather than a heat problem. I'm only hoping that it can be resolved relatively inexpensively

[Doug]

Agree with above -- Ihave some of the same marks on me car. If that's the 'worst' problem with your prospective car then it's a good one . . .

[Andy C]

Thanks for the info .. you guys rock.

This is by no means the "worst" issue with this car, but it was the only one I couldn't explain

[Dovey]

I'm no chemist, so I will take your word on this. But I would still recommend insulating the bonnet if you have a respray. Because 90% of the time this reaction occurs on the bonnet, and I haven't heard that they were made differently to the rest of the car. Also a respray is not going to cure the cause just the effect so it's a matter of time before it comes back. So why does it occur there so often and so badly? I presume heat may not cause the blisters but acts as a catalyst to this chemical reaction.
Besides gaffa taping bacofoil under your bonnet isn't hard...

[chris.t]

The bonnet is already insulated - well mine is anyway