Small bubbles in paint work

[morgala]

I recently bought a car cover for winter months and it's been great, however today I noticed HUNDREDS of small bubbles have appeared in the paint work (left rear end), i don't know if they are bubbles or pimples or whatever, but they are pretty hard.
The funny thing is that it has only appeared on the left rear panel, everywhere else is fine.

Has anyone else had this problem. What's causing it, is it the car cover???


I'm pissed but not too much as I will be getting a full rear end respray in the new year.

[bigblockmark]

Same happened to me on a corvette that i used to own.Was caused by the crap cover that i had not breathing and causing the paint to sweat,had bubbles on all surfaces but especially were the cover laid heavily.Hope that makes sense.Ditch the cover before putting it on your nice new paint job.

[morgala]

this is a bit of a pain in the arse. I've got a heavy duty car cover from classic additions which is great, but if it's going to cause bubbles in the paint work then what can you do?? i don't have a garage and i don't want the car to get lashed on.

bollocks, i keeping the cover on and if i get more bubbles elsewhere then i'll get the whole bastard resprayed next year.

this is car is a bloody hassle at times....

[simpo two]

Has the area been resprayed recently?

[V8 Archie]

Osmosis, it's called. It's caused by water getting into the fibres of the GRP. Valhalla is a bit of an expert.

I've got a couple of small patches too and I don't use a car cover (I have a garage).

Thus far I'm at a bit of a loss as to how it might of happened. All I can think of is that I might have exposed fibre inside a couple of wheel arches.

[morgala]

simpo two - hasn't been sprayed recently.

when i first bought the car there was a very small patch (5 or 6 bubbles) which was acceptable, it just sprouted since the introduction of the cover.

if it is the cover shall i expose the rear frequently just to give it some air.

[Big Al.]

Osmaosis is frequenty found on fibre glass boat hulls
This link I think explains the problem and the cure.

www.brava.it/osmosi_e.htm

Hope this helps

[redwedge5]

My 3000M got covered with microblisters when it was stored in a damp garage. I was told it was a moisture related problem. Sounds similar.

My SEAC isn't garaged. I rely on a LT hood cover which keeps most of the rain out and protects the hood. This might be better than a full cover. At least the paintwork can dry off when it stops raining.

[morgala]

thanks for the help. Maybe i should have gone for the LV hood instead of the full cover - i only got the full one just to kerb my paranoia, which has sadly backfired.

well as it close to xmas i can't justify buying a new hood, so i'm just going to use the one i've got. roll on the new year and get the respray done.

[chimhunter]

I've got the same problem. Funnily enough I've also got a Classic Additions heavy duty car cover. I wonder if it's related to putting the cover on when the car is slightly wet? The cover is supposed to be breathable...

[Z 's dead]

i was told by classic additions not to use the heavy duty waterproof cover on vehicles that are AT ALL damp when covering them. these covers are solely to be used on bone dry cars, probably for this reason.

You can buy a showerproof one from them that will be 98% waterproof anyway but allow the car to "breath" and therefore can be put on the car whilst its wet or damp. Even in v heavy rain it will protect the bulk of it from getting in the car.

[N4 SPY]

I had a similar experience with a Golf GTi (excuse the language) years ago where the whole of the roof started showing these small dimples. The car had been fully resprayed 2 years before I bought it and a local paint shop believed it was as a result of inadequate preparation before spraying. Not sure if it would have anything to do with the car cover myself!

All the same it's a right pain in the butt!!!

Cheers

[MikeyT]

My old Mustang had these small bubbles (microblistering) on the surface of the paint. Looked great from five yards mind - just bad up close. On the flat surfaces only, boot, bonnet, roof etc not the doors.

I was told it was because it had been kept under a cover whilst damp. And the 'breathable' cover didn't do what it was supposed to.

I'd never cover a damp car though, simply because of this problem which could occur.

[alan_d]

For osmosis to occur there must be a semi-permeable membrane - in this case it could be the paint or the GRP gel coat (although I don't think TVRs have a gel coat like boats do, because they're filled and faired before painting). Its unlikely to be the laminate that's blistered, but the only way to check is to de-cap one of the blisters. Obviously you don't want to do that until you're ready to re-spray. IMO if the blisters are clustered it could be a patch where the paint is relatively thin.

I've had the same thing happen on mine BTW - pin-head sized blisters - now I leave the cover off most of the time.

Alan

[Morgala]

chimhunter said:

I've got the same problem. Funnily enough I've also got a Classic Additions heavy duty car cover. I wonder if it's related to putting the cover on when the car is slightly wet? The cover is supposed to be breathable...

exactly, there a solution other than a garage. If you leave it off it get lashes on and leaks - i've already thompson watersealed it (twice) and that does cock all difference.

or you splash out on yet another car cover, which quite frankly i'm not prepared to do as it's near xmas.

the thing is...when you take it out and it starts raining, you put the cover back on you don't have time to wipe it down...anyway going for a pint with the lads from work, will speak later

[heliox]

This sounds like a bad repair catching up with you.

It may not be osmosis but a paint defect due to the high humidity, ive seen this quite a few times this year ranging from body filler expansion to incorrect resin hardener quantities. Only way to get rid of the problem is to strip the paint down to the glass and re-resin,sorry.

hope all goes well

h