Warped/bulging pop top

Thin bits of metal and bright blue light. Including glass & trim.

Moderators: User administrators, Moderators

Post Reply
mariner
Registered user
Posts: 379
Joined: 05 Jul 2011, 20:04
80-90 Mem No: 9916
Location: Bristol

Warped/bulging pop top

Post by mariner »

Hi all. I've a super viking pop top and about 3/4 weeks ago I noticed that a section of the pop top has warped and in between the two hinges the side of the pop top has bulged outwards. It used to sit snugly inside the gutter line but now this section sits out beyond the gutter meaning there is far more flex when pushing the pop top inwards at this point than there should be.

I recently treated the fibreglass with some gel coat restorer. Could this be what's caused it? Or is this something that can happen to aged fibre glass? Being a super viking it's about 14 inches high so quite a bit of room for movement.

Any advice would be much appreciated as I'm keen to get it back to its original fit, although I'm a bit worried that might not be possible. :(

Added a couple pf pics from either end of the van that show how it's bowed out and one for the other side where the roof still fits neatly above the gutter.

BGWY5453.JPG
(82 KiB) Downloaded 35 times

HOOK6510.JPG
(82.87 KiB) Downloaded 35 times

VZTU1462.JPG
(105.77 KiB) Downloaded 35 times
1985 Super Viking with Subaru EJ22 (formerly 1.9 petrol DG)
1981 air-cooled 2.0 high top

Michael4
Registered user
Posts: 450
Joined: 08 Aug 2018, 14:43
80-90 Mem No: 16731
Location: Chichester West Sussex

Re: Warped/bulging pop top

Post by Michael4 »

If you push up in the middle (from the inside) does it go back to the original shape?
1985 1.9 DG Devon Moonraker with solid sided pop top

User avatar
slowcoach
Registered user
Posts: 1575
Joined: 06 May 2010, 10:23
80-90 Mem No: 8892
Location: West Yorkshire
Contact:

Re: Warped/bulging pop top

Post by slowcoach »

Odd that it's done that in a short time- are you sure you'd just not noticed it?

Fibreglass roofs definitely flex, and over time with some load applied, they can definitely change shape permanently. I know this as my roof has changed shape from the weight of my solar panel (it's heavy), but it's been up there for about 8 years. Have you changed anything with the fixings or added anything?
===================
1984 TRAKKA Conversion Subaru EJ20 5 Speed

mariner
Registered user
Posts: 379
Joined: 05 Jul 2011, 20:04
80-90 Mem No: 9916
Location: Bristol

Re: Warped/bulging pop top

Post by mariner »

There's no sag in the middle section of the roof, just the bowing of this one section.

It's definitely something that is recent and does seem to have been quite a quick change rather than a slow one over time. The only thing I've done to the roof is the gel coat about two/three months ago, but I did the whole roof so I don't think that wouldn't account for it just being this one section. It did seem to happen at the same time as the hot spell we got early on in the lockdown and I wonder whether that might have something to it?
1985 Super Viking with Subaru EJ22 (formerly 1.9 petrol DG)
1981 air-cooled 2.0 high top

Michael4
Registered user
Posts: 450
Joined: 08 Aug 2018, 14:43
80-90 Mem No: 16731
Location: Chichester West Sussex

Re: Warped/bulging pop top

Post by Michael4 »

I asked about pushing up in the middle because cheap grp boats can splay out if poorly designed/built. Normally there is some form of bracing glassed in, might look like ridges across the inside of the roof.
1985 1.9 DG Devon Moonraker with solid sided pop top

PeteandNikki
Registered user
Posts: 296
Joined: 08 Jul 2014, 09:23
80-90 Mem No: 13990
Location: 10 miles south of Bristol

Re: Warped/bulging pop top

Post by PeteandNikki »

Personally I would suspect a combination of the hot weather and the restorer. GRP does expand and contract slightly with temp change. I would think that maybe the restorer soaked into the GRP and caused it to expand ,although only by a little, Anywhere else on the roof would be able to move freely, but the section between the hinges would be restricted by the hinges being fixed points.

I frequently carry out GRP flat roofing and have encountered similar problems although not related to applying ‘restorer’ Coincidentally I happen to also have a Super Viking.

I’m no expert but that’s my best guess!

User avatar
Mr Bean
R.I.P.
Posts: 3532
Joined: 11 Jun 2008, 06:49
80-90 Mem No: 5485
Location: Hertfordshire

Re: Warped/bulging pop top

Post by Mr Bean »

I agree with the suggestion that it might have expanded and further more that it could be bulging out due to being restrained between the hinges. You could prove or eliminate this theory by slackening the fixings to see whether it straightens out. If this were the case slightly elongating the fixing holes could be a solution.

Were the problem was caused by tightening the over square latches while the fibreglass was softened by the treatment then one might be tempted to re-treat and jig the panels straight during the hardening stage. This does seem a bit drastic but the Carpenters twisted wooden door trick could work without the re-treatment where packing piece is placed in the door jam for a couple of days so as to twist the door back into shape.
In the case of the van this would involve springing the panels back into shape (or a bit more) i.e. together and somehow retaining them in that position for a couple of days (wooden battens and string or thin wire) in the hope that they will stay in pace once released this being assisted by the sun (fat chance :roll: ) and more likely to stay good if there is some feature to capture it like sitting inside the gutter for instance.
Well-timed silence hath more eloquence than speech.
"A quiet shy boy who took little part in games or sport"
88 High top 2.1 WBX

Da dan
Registered user
Posts: 612
Joined: 16 Sep 2015, 06:00
80-90 Mem No: 0

Re: Warped/bulging pop top

Post by Da dan »

What do you have inside the roof pushing out or have you not put the cushions away properly? I have the Viking too and it will get this when I have all the duvets up there and when a water bottle fell down without me seeing it once!! The fibre glass skin could have also split as they seem to be moulded around a wooden/metal frame then fibre glasses from both sides. To see this take off the seal around the outside and all will show as you will see it.


Sent from my iPhone using Tapatalk

User avatar
Cobra88
Registered user
Posts: 909
Joined: 03 Apr 2018, 18:24
80-90 Mem No: 16481
Location: Ipswich

Re: Warped/bulging pop top

Post by Cobra88 »

I have seen similar when a crack has allowed water into the encapsulated wooden stiffeners in some poptops allowing them to swell in sunny weather.

probably worse if whatever used to clean has sealed the water in
____________________________________________
84 CaravelleGL 1.9 DG WBX Bronze Beige Metallic auto

mariner
Registered user
Posts: 379
Joined: 05 Jul 2011, 20:04
80-90 Mem No: 9916
Location: Bristol

Re: Warped/bulging pop top

Post by mariner »

Thanks for all the replies guys. A bit embarrassingly, it seems that I may well have let one of the cushions slip down and push out against the roof. I did have the roof up to check this a few weeks ago but must have missed it somehow :oops: Thanks Da dan for the nudge to look properly! I will now go and take a good long look at myself in the mirror :rofl
1985 Super Viking with Subaru EJ22 (formerly 1.9 petrol DG)
1981 air-cooled 2.0 high top

User avatar
Cobra88
Registered user
Posts: 909
Joined: 03 Apr 2018, 18:24
80-90 Mem No: 16481
Location: Ipswich

Re: Warped/bulging pop top

Post by Cobra88 »

:ok
____________________________________________
84 CaravelleGL 1.9 DG WBX Bronze Beige Metallic auto

PeteandNikki
Registered user
Posts: 296
Joined: 08 Jul 2014, 09:23
80-90 Mem No: 13990
Location: 10 miles south of Bristol

Re: Warped/bulging pop top

Post by PeteandNikki »

Brilliant! I’m a bit ashamed of myself for not spotting the obvious, having done the same myself previously. Guilty of overthinking and trying to be ‘clever’ maybe!

Da dan
Registered user
Posts: 612
Joined: 16 Sep 2015, 06:00
80-90 Mem No: 0

Re: Warped/bulging pop top

Post by Da dan »

There is a lot to pack away. So I think your forgiven!!! Won’t be my last time either [FACE WITH TEARS OF JOY]


Sent from my iPhone using Tapatalk

Post Reply