Sikaflex....what one?

76zedfour said:
i used 292i as advised by aandncaravanservices in their solar panel install guide however the roof bolts bit seemed ridiculous to me. The top layer on a motorhome is a very thin sheet, presumably aluminium, glued to an insulation board. If the sikaflex gives way and a solar panel is loose then no way is a roofing bolt going to hold a panel in place screwed into 1mm of aluminium whilst meeting a combined 110mph uplifting headwind as suggested by some folk. Still if it makes people feel better about the limits of a glue that holds aircraft and speedboats together then so be it.
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mine's a sprinter with a steel roof. if it was a flimsy , i'd use through bolts with big washers
 
mr brown said:
don't forget , no matter what the roof is made of , you're just gluing to the topmost paint layer. i use roofing bolts as well
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not always ;) I fitted a pair of semi-flexible panels with a Fibreglass Backing to a pop-top roof which was not painted, but a self-coloured GRP (I confirmed this with the manufacturer before fitting). In that case I used 3M VHB Tape - and around 15 Metres of the stuff - that sucker ain't going anywhere (in fact as soon as the panel laid down it was solid).
But generally speaking, would never rely on adhesive for a glass framed panel.

mr brown said:
mine's a sprinter with a steel roof. if it was a flimsy , i'd use through bolts with big washers
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My glass panels are fitted to roof rails; but the roof rails, as well as being taped down, are through-bolted the metal roof with penny washers acting as spreaders on the insided before the nut. I did consider riv-nuts briefly but didn't like the lack of load-spread. I also never considered relying on adhesive to hold on top of the paint (and Sprinter roof paint is renowned for peeling to boot!)
 
Sika tech guys told me I needed to use 252i architectural, on second panel added later I used Stixall
 
and another thing , while these glues may be used to stick aeroplanes and boats together , that will probably be done in a sterile, temperature and humidity controlled factory environnment,with clean ,unpainted mating surfaces, by technicians who know what they're doing , not some old bloke balancing on a wonky stepladder, on the road outside the neighbour's gaff, slapping it on with a dirty paint scraper in a rush to get it on before the bloody rain starts again.
and sod trying to spanner bolts on as well !
 
I would still advise if possible to put some form of screws as well as bonding it.
We have seen installations come in here, where the damage is horrific when you rely on a small layer of paint/roof material of a van in most cases (thin layer of Ally or Fibreglass, then ply underneath that layer in most cases with Coach-builds). With the RV's you also have in some cases a Vinyl Roof, so extra care is needed when putting solar on them.
You only need to get under some low lying trees and something hooks up underneath it!! We also have heard of them coming off whilst driving, where its peeled the paint/thin top skin and flew off.
We would always advise to put tack screws in theroof where possible.
 
Allen said:
Thanks everyone for your input.
I've gone with the majority verdict both here and elsewhere on the internet and ordered 512.
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So if you are only going to be gluing on the solar panel, make absolutely certain that the surface area you are attaching it to is cleaner than clean.
 
I have only ever glued one solar panel so am no expert but i refer people to this from a source I have found very knowledgeable


What adhesive should I use to attach my Flat Glass Solar Panel?

A motorhome travelling at 70mph into a 40mph head wind, effectively has a 110 mph hurricane blowing across the roof top. That can be a huge force acting on a Solar panel so we think 'belt and braces' security should be the order of the day.

We suggest Sikaflex 292i which is described as a "HIGH-STRENGTH FASTENING ADHESIVE FOR STRUCTURAL ASSEMBLY". It is suitable, even in challenging Marine environments.
Many forums advocate the use of Sikaflex 512 Caravan Sealer.adhesive which is primarily a sealant that also has some bonding properties. Sika say it is NOT a structural adhesive.
Sikaflex 292i is a full marine grade structural adhesive, not that different to Sikaflex 252, but 292i has superior Salt water and chemical resistance and 3 times less shrinkage than the 'best of the rest' so far less chance of there being gaps letting water in the roof.
Sikaflex 552 also gets a recommendation by the Sikaflex team, but the tensile strength of 292i is slightly superior.

Note that neither Sikaflex 252 or 292i are suitable for gluing all Plastics, 252 has a warning that any plastic under stress and potentially subject to stress cracks, MUST NOT be used with 252. The same applies to 292i.
Some of the adhesives specifically mention they are not suitable for ABS plastic which was the material used by one set of feet we saw.
Other adhesives, like the Dekasyl MS2, have notes in the documentation that they are also unsuitable to bond some plastics, like ABS.
 
You lot have got me worried now... my 2010 ducato pvc has a solar panel right at the front of the roof and being a ducato, paint is already peeling in the gutter areas. I have no idea who fitted the panel nor how it is fixed. I can see white sealant/adhesive but cannot see any screws/bolts due to the design of the brackets. I have not yet had a look under the ceiling covering but will do tomorrow.
I dont want mine going awol
K ?
 
Vanterrier said:
You lot have got me worried now... my 2010 ducato pvc has a solar panel right at the front of the roof and being a ducato, paint is already peeling in the gutter areas. I have no idea who fitted the panel nor how it is fixed. I can see white sealant/adhesive but cannot see any screws/bolts due to the design of the brackets. I have not yet had a look under the ceiling covering but will do tomorrow.
I dont want mine going awol
K ?
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''I dont want mine going awol '' or any passers by going ow !
 
Think if you use the correct build process . Primer. activator that is comparable with the sealer it will be ok. I Understand putting extra fixings in. And each to there own. Most Windscreens are bonded in. But i don't see any extra fixings in them. And nobody seems worried about a windscreen debonding
 
Never forget that if in a worst case scenario your nice large rigid and heavy solar panel attached to the roof of your van was to go AWOL and it was to slam down onto or into a passing vehicle or a pedestrian you were passing, and it caused either a serious injury or indeed a fatality, then by hook or by crook the law enforcement authorities would hold you to blame and the proverbial book would be thrown at you!

As this is very much the case, then I for one would never, ever risk gluing one of these panels onto my van, most especially as in the case of @Vanterrier when he has little of no faith in the strength of the flaky paint on his Fiat.
 
Silver sprinter said:
Think if you use the correct build process . Primer. activator that is comparable with the sealer it will be ok. I Understand putting extra fixings in. And each to there own. Most Windscreens are bonded in. But i don't see any extra fixings in them. And nobody seems worried about a windscreen debonding
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to be fair , windscreens are glued to a steel flange more or less opposite the wind direction . the wind would be pushing the glass against the flange. a solar panel , with its cooling gap .has the wind pushing up from underneath ,and possibly lifting from above
 
I think that the main point when fixing a flexible panel with sealant is to ensure that the leading edge doesn't allow wind to get underneath.
 
of course ,fitting a flexi panel is a simple matter, plenty of glue , i use stixall , and a length of gorilla tape along the leading edge. it's the big house type panels that need fixing a bit more carefully. my first camper was a morris minor ,and i once had the bonnet fly open , snap its hinges , and sail across the road , narrowly missing a heedless tramp. shook me up a bit,could have really hurt him .so i'll stick to belt and braces
 
Silver sprinter said:
Think if you use the correct build process . Primer. activator that is comparable with the sealer it will be ok. I Understand putting extra fixings in. And each to there own. Most Windscreens are bonded in. But i don't see any extra fixings in them. And nobody seems worried about a windscreen debonding
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Just a mention about the longevity of bonded windows, my Plaxton Cheetah Coach will need the windows rebonded as they are starting to detach!
 
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