Water Bubbles under paint on Ducktail Spoiler : Help!

da.murf

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Hi guys

so last June I had a Tarmac Sportz rivet-less ducktail fitted (fibreglass)

Bodyshop also smoothed and painted my front bumper.

finish and match of Bumper is perfect. Spoiler was also great until maybe September. Then small blister/bubbles started to appear.

photos below : please note this photo was September. There are many more now.

I though they could be air filled, from maybe pours in the fibreglass. They where inspected by painter today and when we pierced one it was full of water.

when we fitted Spoiler afaik It was correctly primed etc etc

the original spoiler holes were Left unsealed under the new ducktail to allow air movement etc.

help guys.... it’s getting sorted next month and I’m working with painter etc to get but at a loss of what could have caused it? Don’t want it repainted etc then for it to occur again

could damp air from car sitting have gotten up under the spoiler through the original spoiler holes and dampened it from below etc ??

really need forums help on this one lol

will add here the painters rep is second to none, and used them many many times, so it’s not a thread about them at all, just looking to see if anyone has came across something like this before?

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da.murf

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da.murf
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I can be of no help at all, but what does the painter himself think?
says he hasn't seen anything like it before (to that extent)

part of me is thinking the original spoiler drill holes needed to be filled. I Get the idea of letting air movement in/out etc, but maybe warm damp air from car/boot made its way into the spoiler cavity through the original holes and then got cold really fast and condensed and then has dampened the fibreglass from the inside?
 

Ben P

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It'll be because of prep, thinners used or moisture during painting.

100% painters issue. Regardless if they are second to none or not, mistakes happen.
 

da.murf

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da.murf
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It'll be because of prep, thinners used or moisture during painting.

100% painters issue. Regardless if they are second to none or not, mistakes happen.

would the same issue not have happened with front bumper? Although it was just re-painting a bumper.
 

Burt2000

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Its down to the to the prep/painting as said above, there has been moisture in there somewhere (maybe in the primer) and extreme weather can cause it to show, it can happen with some of these “breathable” outside covers people use in winter. Plenty have pulled a cover off a car in spring to find the paint has microblistered. Up to the painter to strip it back and do it again, if he’s worth his salt he should re do it.
 

ALN

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Car looks like it has herpes.

Find out what primer was used and how the prep was done. Typical would be a decent etching primer and all surfaces and environment need to be dry including air lines.

Other cause could be with the gel coat on the fibreglass. Defects can cause microfractures and gasses can escape I believe.

I’m not an expert but do a bit of fibreglass work.
 

Ben P

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would the same issue not have happened with front bumper? Although it was just re-painting a bumper.

Potentially they will have prepped the bumper to a higher standard.
 

Brian mc21

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I had this on a copy civic spoiler. Was on about a year before this happened. No idea why but remember at the time the painter said it had been difficult to paint. Had numerous other stuff done by him and never any problems.
 

MarkM

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Micro blisters, sorry for digging up a painful episode @dave b
 

Sportwag

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I had it happen to me with a fibreglass bumper skirt on a Volvo. GRP absorbs moisture over time. This moisture “wicks” to the surface causing small bubbles (micro-blisters). I don't think this was a paint issue and it worsened in cold weather but once the micro-blisters appeared, they never completely disappeared in the warmer weather. It can take a while for these micro-blisters to appear (panel was perfect for several months) but the problem I believe is in the glass fibre. I didn't have the fibreglass repaired as I sold the vehicle but I think part of the remedy is to low bake the panel temperature and repeat this prior to repainting I'm sure some Scimitar, TVR or boat owner will have experience of this.
 

Woodcutter

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I would be fairly sure the issue here is the fact the spoiler is fibreglass, and has retained water somehow. Perhaps it needed sealed before priming & painting. It has to be the reason otherwise the other bits painted would be the same.
 

pedenjohn

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The reason is not or at least unlikely to be the painters fault. I have seen this before but not for sometime, as fibreglass kits just weren’t so common for a while. It’s moisture coming through from below the spoiler. It can affect some fibreglass and not others depending how well it’s made, and also where it is on the car. I feel that sometimes if there are a lot of voids in the fibreglass those also soak up with water. What I do if I have access is to brush paint the back of the part with a 2k direct gloss paint, primer first.

For example I seen it on a front bumper and not a rear bumper, but both painted at the same time.

think about it this way, the the blisters are ‘full’ of water, do you think the painter got it so wrong that he had that much moisture in the job and it managed to stay dormant somehow?... it’s coming through from below and it’s the part itself that is at fault. I’d remove it and paint the underside to seal it. Yes you can have blisters due to damp primer but you wouldn’t have visual pockets of water.

As for saying does the painter have a proper oven?.. well if you bake fibreglass you will cause the air pockets in it to blister, but this will happen straight away. You don’t bake fibreglass
 

da.murf

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The reason is not or at least unlikely to be the painters fault. I have seen this before but not for sometime, as fibreglass kits just weren’t so common for a while. It’s moisture coming through from below the spoiler. It can affect some fibreglass and not others depending how well it’s made, and also where it is on the car. I feel that sometimes if there are a lot of voids in the fibreglass those also soak up with water. What I do if I have access is to brush paint the back of the part with a 2k direct gloss paint, primer first.

For example I seen it on a front bumper and not a rear bumper, but both painted at the same time.

think about it this way, the the blisters are ‘full’ of water, do you think the painter got it so wrong that he had that much moisture in the job and it managed to stay dormant somehow?... it’s coming through from below and it’s the part itself that is at fault. I’d remove it and paint the underside to seal it. Yes you can have blisters due to damp primer but you wouldn’t have visual pockets of water.

As for saying does the painter have a proper oven?.. well if you bake fibreglass you will cause the air pockets in it to blister, but this will happen straight away. You don’t bake fibreglass
Thanks @pedenjohn (also good to see you on the forum)

I mentioned I think initially the post was more try and ensure issue didn’t happen again when it’s repaired.

my very very basic understanding and knowledge I think there is now a pocket of moisture between the oem boot lid and the spoiler. The ducktail is hollow inside so there is a pocket of air there. I think by leaving the oem spoiler holes (they are lined up inside the cavity of the ducktail) unsealed that warm air from the cockpit has moved into spoiler cavity area and then gotten damp etc.

Could my theory be right?

also next question is if the spoiler is repairable? It’s pretty well bonded to the boot lid so removal could be tricky. If I seal the holes from below and the painter strips off old paint etc and repaints could that resolve this ?

sorry for the questions but appreciate your expertise
 

pedenjohn

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Thanks @pedenjohn (also good to see you on the forum)

I mentioned I think initially the post was more try and ensure issue didn’t happen again when it’s repaired.

my very very basic understanding and knowledge I think there is now a pocket of moisture between the oem boot lid and the spoiler. The ducktail is hollow inside so there is a pocket of air there. I think by leaving the oem spoiler holes (they are lined up inside the cavity of the ducktail) unsealed that warm air from the cockpit has moved into spoiler cavity area and then gotten damp etc.

Could my theory be right?

also next question is if the spoiler is repairable? It’s pretty well bonded to the boot lid so removal could be tricky. If I seal the holes from below and the painter strips off old paint etc and repaints could that resolve this ?

sorry for the questions but appreciate your expertise
I’d doubt it if you could dry it through, how are you getting the moisture out from between it? Also how well is it sealed around the edges? Basically what you’d need (in my opinion) is it dry and airtight, because it’s condensation likely. I didn’t seal my boot spoiler very well along the bottom, thinking that if moisture got into it it could get out again, but whether this works for me time will tell, either way I have painted the back of it. What I mean is, if your going to seal it you need to completely seal it... or don’t seal it at all

it’d still want to take it off though, strip the paint and leave it somewhere warm a few days and paint the underside
 

da.murf

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I’d doubt it if you could dry it through, how are you getting the moisture out from between it? Also how well is it sealed around the edges? Basically what you’d need (in my opinion) is it dry and airtight, because it’s condensation likely. I didn’t seal my boot spoiler very well along the bottom, thinking that if moisture got into it it could get out again, but whether this works for me time will tell, either way I have painted the back of it. What I mean is, if your going to seal it you need to completely seal it... or don’t seal it at all

it’d still want to take it off though, strip the paint and leave it somewhere warm a few days and paint the underside

Thanks for reply and that’s the answer I thought was coming and dreaded. But I know you are right.

Will need to chat to the painter now about it all now.

not sure if blame lies on anyone, but when he mentioned he hadn’t sealed the oem holes I was surprised.
 

dave b

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LOL @MarkM there's a blast from the past.

John was going to fix the car for me before it was returned to the original seller so he is the best man to advise on a repair in my mind. I would agree with his explanation as the fault being with the bodykit and not the paintwork as my old car was resprayed but the problem returned for the next owner the winter after that :weary_face:
 
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