Carol
Active Member
But a real risk some more blisters or as is the case with mine 2 large bumps, will appear later
Tiny blisters on roof
- Thread starter ClaireDe
- Start date
Steven rhodes
Member
Well my roof was removed to have a respray, and two weeks later I had water leaking in , when in was perfect before so I'd say get a new roof because it's coming off what ever they do
Steven rhodes
Member
I have had a free service tho so that was helpful under the circumstances
WILLH
Active Member
MB dealers body shops are probably not used to dealing with repairing and repainting GRP or whatever plastic the roof is made from-hence the recurrence.There must be a way that the roof can be repaired and repainted properly in situ by a specialist body shop-commercial vehicle spray booths and ovens could accommodate it easily.
GeorgeG
Active Member
My contact in the Westfalia factory in Rheda-Wiedenbrück suggested some while go, when the problem of blisters first emerged, that the issue was probably related to storing the 'bare' roofs in a cold and damp factory building prior to painting.
In 2015 I visited the Düsseldorf Caravan Salon (incidentally, the biggest motorhome and caravan show in Europe) before I bought a Westfalia Columbus. What particularly caught my eye though were the various Wingamm motorhome conversions which were all based on a monocoque GRP bodyshell. I spent some time on Wingamm and other forums and discovered that a common problem with these bodies is paint blistering. This is also found in GRP boat hulls and GRP sports cars (especially it seems with Lotus). The most common remedy is of course - largely because of cost - sanding down and respraying. A number of Wingamm owners reported several attempts to rectify the issue under warranty with this cheaper fix because the only other alternative was a whole new bodyshell! In some cases the blisters kept recurring and owners gave up. Ironically, this is why I bought a 'metal' Westfalia Columbus and now find myself the proud owner of a Marco Polo with a GRP roof because I couldn't find any reference anywhere to paint blister problems with the MP.
One theory as to why the problem occurs with the Wingamms is that steam generated inside from cooking and especially showering migrates through the GRP and is trapped by the lacquer coat, thereby causing the paint to blister when the conditions are right. I think I'm right in suggesting that the problem only arises in the MP's roof after they have been exposed to frosty conditions which result in the trapped water freezing and therefore expanding to cause blisters. Presumably, if an MP is stored in a garage in winter this is unlikely to occur, or at least delay the occurrence of blisters. Also, I guess that the occurrence of blisters in the MP is mitigated by the fact that the fabric roof sides, when the roof is raised, allows water vapour to disperse and the fact there is no shower to generate masses of steam.
I'm pretty confident that the paint blistering is confined to a badly produced/stored batch of roofs. Providing the factory has remedied these issues it should not re-occur. From my above comments I think you should conclude that a faulty roof should be replaced because of the likelihood of blistering continuing to appear in one of these faulty roofs. My roof was replaced a couple of months ago and so far so good. I wait to see how it is after a few frosts.
Carol
Active Member
I believe you are correct, the problem Lotus has was there doors had been stored outside and the damp got into the fibreglass before spraying
Epigram
Active Member
Thanks GeorgeG.
Freezing of moisture trapped under the gel coat is an interesting mechanism for causing the blisters.
It would be useful to know from those affected, when the problem came to light, such as after frosts or alternatively or after hot days when presumably trapped moisture could have expanded or turned to steam.
I assume the inside of MP roofs are painted and therefore impervious to water vapour. Therefore in the Marco Polo’s case, at least, water vapour should not get into the fibreglass through normal usage e.g. cooking or for that matter sleeping in the van on a cold night !
I think we should assume that moisture was absorbed into the fibreglass prior to painting and therefore a production problem. Hopefully this is confined to a batch, however the polls completed so far don’t seem to be show anything conclusive.
Of course, what is not known is the age/production date of the roofs themselves or details of how Westfalia stored them.
Are Mercedes shedding any light on this or are we reliant on GeorgeG ‘s mole?
Carol
Active Member
My micro blisters first appeared About February after the frosts, after having a new roof fitted with a small bump in the middle , l rejected the repair and during the summer l believe it got more noticeable, probably growling a little also created a small bulge inside on the roof lining . I believe this fits with your conclusion
GeorgeG
Active Member
I’ll contact my mole next week for an update. It’s about 8 months since he told me they were investigating the problem with the likely cause thought to be the way they were stored after production but before painting. He said at the time this was a guess as he put it.
Method7
Active Member
The residue that seeps from these blisters isn’t just water, it’s sticky, like pine sap and that confuses me a lot. GRP as far as I am aware is not soluble in water, whatever is being flushed by this process is no longer in the roof so I wonder how that effects it’s integrity and future.
It could be solvent, part of the paint process
Micro blisters are nearly always caused by moisture
The roofs could have been stored in the damp.
It happens on steel bodies as well, if the primer coat gets cold or damp before the top coat is applied
We also noticed the blisters in Jan/Feb.
I discussed both the roof and bed corrosion with Mercedes back in March - as I noted earlier on this thread, the earliest they said they could do was May - this got pushed back to July but we decided we wanted the van over the summer so it eventually went in for repair / replacement start of Sep.
The roof was replaced but then they realised they didn't have the parts for the bed (even though this was on recall) and did not know when they would get them. So we took the van back (after 3 weeks), then realised the roof didn't fit properly. It went back to back to Mercedes almost 3 weeks ago to have the bed/mattress replaced and roof repaired but again they can't get the parts.
So it is stuck in a Mercedes workshop - very frustrating. From March to now - almost 8 months. How can a 'quality' car manufacturer operate like this?!
I discussed both the roof and bed corrosion with Mercedes back in March - as I noted earlier on this thread, the earliest they said they could do was May - this got pushed back to July but we decided we wanted the van over the summer so it eventually went in for repair / replacement start of Sep.
The roof was replaced but then they realised they didn't have the parts for the bed (even though this was on recall) and did not know when they would get them. So we took the van back (after 3 weeks), then realised the roof didn't fit properly. It went back to back to Mercedes almost 3 weeks ago to have the bed/mattress replaced and roof repaired but again they can't get the parts.
So it is stuck in a Mercedes workshop - very frustrating. From March to now - almost 8 months. How can a 'quality' car manufacturer operate like this?!
GeorgeG
Active Member
I’ve now heard back from my contact at the Westfalia factory. He tells me they are still investigating the cause of the problem with the blisters. They have altered the manufacturing process to some extent and the way they store the roofs is now different (I assume he means better). What surprised me though was that he tells me “a lot” of universities and labs are analysing the problem.
I imagine the issue has been escalated because it must be costing Mercedes/Westfalia a small fortune. He wasn’t able to say with 100% certainty that the problem would not reoccur in replacement roofs supplied up till now.
Method7
Active Member
I had a call from the body shop today... MB have moved the repair to their body shop in Poole apparently because they have several lined up... hop on the conveyor belt.... they said don’t expect any movement until the new year.
I’m not really sure if this is a good or bad thing. I know the local repair shop is spot on and it’s only down the road so I’m a little disappointed.
I’m not really sure if this is a good or bad thing. I know the local repair shop is spot on and it’s only down the road so I’m a little disappointed.
GeorgeG
Active Member
I
I live near Dorchester but chose to take my MP to Poole Mercedes because they had experience of roof replacement. They do not have a bodyshop for painting because my roof had to go, ironically, to a bodyshop in Dorchester for painting and then returned to Poole for fitting. Karl, the manager at Poole, expressed surprise when he discovered my nearest dealer was Dorchester. I explained that when I discussed it with Dorchester Mercedes service department, mentioning that Poole had replaced two or three roofs, they had no hesitation in suggesting I take it there!
My MP has gone in today to have a new roof fitted. I took it in to the local MB dealer and they have not got a clue what I was in for. That didn't fill me with confidence. They are sub contracting the whole job to a third party body shop. I have actually visited the body shop and spoken to the manager. He said they have already done two and had no problems. Hope that's the case with mine.
Will keep everyone up to date with progress.
Will keep everyone up to date with progress.
Got my MP back today after they fitted the new roof. It took exactly 2 weeks.
The weather is absolutely foul so I can't really check whether they have done a good job, or whether anything not working properly yet. Will check it out when weather is better. Fingers crossed.
The MB dealer fitted a new aux battery under warranty because they said the voltage was low and the body work people couldn't get the roof to go up. I am happy with that.
The weather is absolutely foul so I can't really check whether they have done a good job, or whether anything not working properly yet. Will check it out when weather is better. Fingers crossed.
The MB dealer fitted a new aux battery under warranty because they said the voltage was low and the body work people couldn't get the roof to go up. I am happy with that.
funkyegg
Active Member
Hi Askho,
Did you get a chance to inspect your new roof yet? My local dealer at Epsom also referred my vehicle to Fastlane, 3rd party body shop to have the roof replaced...so would be keen to hear about your experience. Thanks
Only managed a casual inspection as weather is still foul. Looks OK. At least roof opens and closes OK. Only thing so far is they have left out the Westfalia badge at the back. I specifically asked them to replace it. They said they will order the badge and get it sorted.