My car has got spots!
Discussion
Hi all.
I need your help! As the race season has ended, my car has been trailered over from Wales, where my race team looked after it, and for a few months now it has been sitting in the garden with out a cover.
Today i decided that enough was enough and the car should be coverd, so i hosed it down with some warm water and noticed that under the white paint there are small spot like things!
Is there anything that can be done or is their a way of gettingrid of these spots?
Thanks in advance!
Michal
I need your help! As the race season has ended, my car has been trailered over from Wales, where my race team looked after it, and for a few months now it has been sitting in the garden with out a cover.
Today i decided that enough was enough and the car should be coverd, so i hosed it down with some warm water and noticed that under the white paint there are small spot like things!
Is there anything that can be done or is their a way of gettingrid of these spots?
Thanks in advance!
Michal
fortjefferson said:
I'm not a pro, but have done quite a bit of spraying in my time. This looks like bad prep work before it was sprayed. You won't get rid of it short of a respray IMO. John
Agreed, looks like grit or similar under the paint - could it be rust trying to come through? Go on try to break a 'bubble' with a screwdriver or similar? (Pick a less obvious sited one!)
Paul, likes picking spots
little RZD said:
Could be although i washed the car on thursday and i know that these spots were not present! Would frost have caused this?
Cheers
Michal
Could have if moisture was under the paint. Water expands as it turns to ice. As the bubble is below the surface I can't see a way of getting rid of them short of removing the paint and starting again.
Momentofmadness said:
Agreed, looks like grit or similar under the paint - could it be rust trying to come through? Go on try to break a 'bubble' with a screwdriver or similar? (Pick a less obvious sited one!)
I think its more to do with the water rather than grit as the spots are soft and they have just recently appeard, but im no expert! Im 100% sure its not rust coming through as the car is made from GRP.
Michal
A quick google:
If you use a car cover, put it on while the car is clean and dry to protect against dust and possible scratches. DO NOT cover your car with plastic or one of those blue tarps you get at the hardware store, It only traps moisture. Trapping moisture between the finish and a piece of plastic will make the paint bubble and rust will begin to form.
Not that yours will rust of course
If you use a car cover, put it on while the car is clean and dry to protect against dust and possible scratches. DO NOT cover your car with plastic or one of those blue tarps you get at the hardware store, It only traps moisture. Trapping moisture between the finish and a piece of plastic will make the paint bubble and rust will begin to form.
Not that yours will rust of course
Micro blisters. It's water under the paint. The water was there before the paint was applied. Bad prep, I'm afraid.
Sand it down and start again...or just leave it.
It's a race car, you say? Well chances are someone will change it's shape during next season, which will mean a bit of bodywork repair anyway!
Sand it down and start again...or just leave it.
It's a race car, you say? Well chances are someone will change it's shape during next season, which will mean a bit of bodywork repair anyway!
It looks like a problem called osmosis, and it's quite common on glassfibre cars that have been resprayed.
Usually, it is water trapped when the car was wet-and-dry sanded prior to painting, that finds its way up to under the surface of the paint through the porous, wick like structure of the fibreglass. Sometimes, the glassfibre is porous enough to suffer just when the car has been stored in damp conditions, regardless of the quality of the paint job. If you carefully prick one of the blisters with a pin, you will find that it is full of water. Occasionally you will find a similar problem caused by incompatible chemicals used in the respray process - most often where a chemical paintstripper was used to remove the previous paint.
It is therefore most likely down to a poor spray job (specifically, not allowing the shell to thoroughly dry out after wet-and-dry flatting between coats, which can be very difficult in a poorly heated or damp garage) and I'm afraid that as a result there is not much you can do about it beyond stripping the shell back to bare glassfibre and starting again, preferably drying the car out in a low-bake oven once you have stripped it.
You will find that it is seasonal, though; not quite sure why (perhaps the fibreglass dries out in summer and draws the moisture back down?), but my old Elan used to get spotty in autumn, but the blisters shrunk away again the following spring to the point where they were barely noticeable by mid suumer!
Usually, it is water trapped when the car was wet-and-dry sanded prior to painting, that finds its way up to under the surface of the paint through the porous, wick like structure of the fibreglass. Sometimes, the glassfibre is porous enough to suffer just when the car has been stored in damp conditions, regardless of the quality of the paint job. If you carefully prick one of the blisters with a pin, you will find that it is full of water. Occasionally you will find a similar problem caused by incompatible chemicals used in the respray process - most often where a chemical paintstripper was used to remove the previous paint.
It is therefore most likely down to a poor spray job (specifically, not allowing the shell to thoroughly dry out after wet-and-dry flatting between coats, which can be very difficult in a poorly heated or damp garage) and I'm afraid that as a result there is not much you can do about it beyond stripping the shell back to bare glassfibre and starting again, preferably drying the car out in a low-bake oven once you have stripped it.
You will find that it is seasonal, though; not quite sure why (perhaps the fibreglass dries out in summer and draws the moisture back down?), but my old Elan used to get spotty in autumn, but the blisters shrunk away again the following spring to the point where they were barely noticeable by mid suumer!
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