Sikaflex....what one?

76zedfour

Free Member

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9
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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grath

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2,769
How about 6 inch nails bent over on the inside ?
and I could be sick on it and I could be flexible :LOL:
 

trevskoda

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1,326
I used fence post/panel mounting brackets and bolted through,anything stuck down is only to a thine layer of paint which is at its best poor,just remember if it comes of and hits someone you will be in the pokey .sp 4.jpg
 

mr brown

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440
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.
mine's a sprinter with a steel roof. if it was a flimsy , i'd use through bolts with big washers
 

wildebus

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2,122
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
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.

mine's a sprinter with a steel roof. if it was a flimsy , i'd use through bolts with big washers
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!)
 

nabsim

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2,024
Sika tech guys told me I needed to use 252i architectural, on second panel added later I used Stixall
 

mr brown

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440
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 !
 

nickvanbitz

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96
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

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Thanks everyone for your input.
I've gone with the majority verdict both here and elsewhere on the internet and ordered 512.
 

Millie Master

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346
Thanks everyone for your input.
I've gone with the majority verdict both here and elsewhere on the internet and ordered 512.
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.
 

76zedfour

Free Member

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9
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.
 

Vanterrier

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1,271
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 ?
 

grath

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2,769
After reading all this and speaking to the Sikaflex people, I am more than happy with my 252.
It hasn't moved and I put the correct thickness, cleaned the roof and the fittings with the proper stuff.
Not forgetting that my set up is aluminium to aluminium
 

mr brown

Full Member

Messages
440
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 ?
''I dont want mine going awol '' or any passers by going ow !
 

Silver sprinter

Full Member

Messages
186
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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