# Paint Blistering of A Class Panels



## Jolleyholiday

Having now had my A Class Burstner Aviano i675 2007 model since March and having enjoyed several trips out I was gutted to notice since returning from a very wet jaunt up the M6 to the CCC Windermere site, that paint is blistering on the bonnet and front panels! I have asked a local body repairer for and opinion and they have told me its water under the paint that has caused the blisters. They say that its not uncommon on fiberglass panels, that i is age related and any repair would possibly only last 2 years before it would need to be done again. I am glob-smacked at the prognosis and wondered (1) if anyone else has had a similar problem (2) Does any one know of a preventative measure that can be applied to the panel before during or after repaint. Surely this cant be right boats are made of fiberglass for goodness sake. Any advice would be welcomed.


----------



## nicholsong

Yes it happens on boats also, including mine.

It is caused, after time, by osmosis, which is water being drawn into the fibreglass - although more likely on a boat which is constantly wet. 
The characteristics are that if you prick a blister it weeps.

I am srprised that it occurred on a motorhome, particularly a good marque like Burstner. Is it possible that it had a previous body repair and that only a thin layer of non-epoxy gel coat was applied?

The cure is to grind back the fibreglass to a level where all the blisters have disappeared. Then to layer up the fireglass, after which a final gel coat is applied to produce the smooth finish. 

The cure is that this gel coat should be epoxy resin which is impervious (or nearly) to the water ingress.

I had my boat done 10 years ago and no problem since.

If boatbuilders, and motorhome builders, used epoxy in the original build there would not be a problem but for an average cruising boat it adds 1,000+ quid to the price.

If your bodybuilder has little experience of doing this work maybe you should consider going to a boatyard which specialises in the work. One very good but expensive system to use is West's, but it is probably not nessary for a vehicle that is only wet part of the time.

Hope this helps.

Geoff

P.S it is a labour-intensive job so not cheap - might be worth contacting Burstner re cost of replacement panels. Also if there has been no repairs previously have a go at them for why it happened and see if they will contribute to repairs.


----------



## dickdastardly

I had loads of tiny blistering on an expensive light weight gel coated car.

Never understood why, but they completely went until the next down poor.


----------



## VanFlair

I dont understand why blisters should be caused by rain on a bonnet even if the gel coat is not waterproof (which it basically is) the paint should offer enough protection, my understanding of osmosis in boats is that the moisture is drawn into the laminate over a prolonged period in the water and it then starts a chemical reaction with some impurity in the laminate, this chemical reaction then builds up pressure in the laminate which causes the blisters between the gel coat and the laminate in which case these blisters would be quite large. As suggested by nicholsong these blister will weep if pricked.

If the blisters are very small and dry if you were to burst one I might be tempted to suggest that it is more to do with the paint on the bonnet than the fibreglass moulding.

Do you think that the front of the vehicle has had some repair work before you became the new owners.

Of course none of this really helps you with your problem.

I would think that the only solution is to remove the paint and reseal the abraded surface with a gel coat, I would have thought that a polyester gel would be OK for this situation as the motorhome does not sit in water.

I understand that this is very upsetting and you have my sympathy if it helps (I doubt if it will).

martin


----------



## Jolleyholiday

*Burstner Bodywork Warranty*

Thanks for the replys on the blistering. Its becoming a theme when I discuss this anywhere that the bended ear kind enough to listen alway says 'Have you spoken to Burstner?" As I am the present carer for this vehicle and not the original purchaser can any one tell me if Burstner from new have a Body Guarantee and what conditions would have to be in place for it still to be valid 6 years down the line?
As always happy to hear any comments.
Regards
Ian


----------



## Bubblehead

Hi

We have the same problem on our bonnet and grey panels around the bonnet / up the sides of the windscreen.

I was told that it was down to a botched re spray. We bought the van 18 months old / 1000 miles, so excepted this. Our van is a 57 plate and now out of its 5 year body work warranty, but was within it when the bubbles first appeared.

Interesting to hear that you have the same problem.


----------



## cater_racer

JollyHoliday

Take it to GRP specialist they can effect a permanent repair, I had Lotus Esprit which showed this after a poor quality repair.

I found an outfit close to me in Cheshire which had specialized with Marcos and they did the job properly and it never re-occurred.

HTH

Gerry


----------



## 113016

Hi Jolleyholiday.
I have one important factor that has not been mentioned. Are they gelcoat blisters or paint blisters? I say this because we have a silver Hymer and the silver on the bonnet and front bumper, is paint and NOT gelcoat. If this is the case osmosis is not the problem!
This is the first thing to establish and in your first post you mentioned paint, not gel.
I would try to establish this first.


----------



## TIM57

For a full explanation read this article 
http://www.hmgpaint.com/knowledge-base/blistering-the-causes-and-prevention
Tim


----------



## VanFlair

Grath said:


> Hi Jolleyholiday.
> I have one important factor that has not been mentioned. Are they gelcoat blisters or paint blisters? I say this because we have a silver Hymer and the silver on the bonnet and front bumper, is paint and NOT gelcoat. If this is the case osmosis is not the problem!
> This is the first thing to establish and in your first post you mentioned paint, not gel.
> I would try to establish this first.


The fibreglass panels will be gel coated even if they are painted as well, if the panels are metalic they will be painted for sure. You can usually tell by the finish and the fact that any small stone chips on a painted colour will show through white whereas a gel coat will be the same colour through the stone chip.

Martin


----------



## 113016

VanFlair said:


> Grath said:
> 
> 
> 
> Hi Jolleyholiday.
> I have one important factor that has not been mentioned. Are they gelcoat blisters or paint blisters? I say this because we have a silver Hymer and the silver on the bonnet and front bumper, is paint and NOT gelcoat. If this is the case osmosis is not the problem!
> This is the first thing to establish and in your first post you mentioned paint, not gel.
> I would try to establish this first.
> 
> 
> 
> The fibreglass panels will be gel coated even if they are painted as well, if the panels are metalic they will be painted for sure. You can usually tell by the finish and the fact that any small stone chips on a painted colour will show through white whereas a gel coat will be the same colour through the stone chip.
> 
> Martin
Click to expand...

Martin,
I do understand the difference between Gel and paint as I sold boats for about 20 years, but is it paint blistering or gel blistering?
Our Hymer did have, a couple of very small blisters on the front skirt. They were paint blisters and Hymer in Germany did a respray, under warranty. This is not osmosis, which is a much scarier thing.
My question was is it gel or paint blisters?


----------



## VanFlair

Hi Graham

Sorry, didnt know your background, just for the record I have 20 years running a composite business making GRP and carbon/Epoxy mouldings. I agree that it will not be osmosis as surely these panels would need to sit in water to be affected that way. I guess the way to decide what is blistering is to dig into one and see how deep it goes.

PS just for the record my money is on it being paint.


Martin


----------



## 113016

Hi Martin, Thanks.
I am no expert, but I have done a few minor gel repairs and i don't think it will be osmosis. I think we need more exact information. I was thinking that if the gel has been painted, they could be simple stone chips that have blistered a little. maybe water got in after the stone chip and blistered under the paint, but not below to the gel.
It needs checking!


----------



## VanFlair

As you say, needs checking and we are just guessing which is difficult without even seeing.

Martin


----------



## Jolleyholiday

Wow thanks for all the reply's. It is also good to know that I am not the only one with the problem. I did read through the link Tim posted but it seems to refer only to painting metal panels. I am interested in the name of the firm Gerry took his esprit to as we are in North Manchester and it may well be in striking distance.
The blistering is on the white painted fibre-glass bonnet and also to the silver trims around the lights and valance the trims up the side of the windscreen are unaffected. I think the panels are painted on top of a gel coat as before this occurred there was a few stone chips on the bonnet. However the speed in which the paint blistered was a shock. Being my pride and joy I do spend a little time polishing the Burstner.
Before we set off for 2 nights in the Lakes no sign of anything on return loads of blisters ranging from small pin head clusters in patches to 5 mm bubbles much worse on the bonnet. I am no expert but I would say only the paint is blistering there is no sign of what I imagine to be a de-lamination of the gel coat from the fibre matting. On pressing a blister it does seem to bleed water. Any thoughts on if a hard frost would accelerate the problem? There would not seem to have been any accident damage to the front end its in a very clean and straight condition on top and underneath. The 12500 miles with a few stone chips seems to be in keeping with a 2007 plate vehicle. I guess I am concerned about having it repainted only to have the problem returning in a few years.
Thanks for the comments.
Ian


----------



## dazmug

Hi

I too have a 2007 Aviano i675. There are some minor blisters on my bonnet, but I have not researched this yet. If I hear of any solutions I will post.

The front panels do get quite a hammering so I expect that the damage will start from minor chips, which of course does not affect boats!

Whilst posting, I have just received a replacement grey water tap. My old one fell off somewhere in France. Have you any experience of replacing these?

regards
Darren


----------

