tanuki.himself
Active member
Its 4 months since I mounted my solar panels and almost all the mounts have cracked
The questions now are why and what to do about it.
The mounts were supplied by a solar panels supply company listed as specifically for motorhomes and caravans and so far their response is "its the screws you have used" which is pretty lame and unhelpful.
The screws are actually 4mm stainless bolts through the mounting and panel aluminium frame with a washer, nut and threadlock on the back. I fitted the mounts to the panels on the bench so they are a flush fit but i don't think overtightened, then i glued the whole thing to the roof with Sikaflex 252 - it was easier to put the glue on the bottoms of the mounting and then let gravity and the weight of the panels bed them down onto the fibreglass roof.
Panels were mounted one evening in the summer with a reasonably high ambient temperature but not direct sunlight, so one possibility is thermal expansion/contraction of the panels in direct sun or overnight cold. Should i have left some sort of gap/padding between panel and mount to allow some amount of movement?
Its only been driven a few KMs at low speed so far but with a lot of swaying and bouncing, so whilst it could be movement and flexing of the whole setup , its not likely to be wind load - but obviously that would become an issue at high speeds.
Its now extremely difficult for me to reach the panel mounts in the centre line of the roof as its high up and i have limited reach on my stepladders. I'd also be concerned about trying to cut through the adhesive and doing damage to the fibreglass roof to remove the mountings, so my inclination is to leave them in place to support the weight of the panels, as long as they are not going to damage or crack the panels by constraining them round the edges and corners, and to tie the panels down to the roof with some more angle brackets, possibly aluminium angle, probably made from woven fibreglass tape which is strong in tension and would probably give a better bond onto the roof using the same Sikaflex 252 - my understanding of aluminium is that even with intensive cleaning its still a bugger to glue reliably.
Thoughts and suggestions please...
The questions now are why and what to do about it.
The mounts were supplied by a solar panels supply company listed as specifically for motorhomes and caravans and so far their response is "its the screws you have used" which is pretty lame and unhelpful.
The screws are actually 4mm stainless bolts through the mounting and panel aluminium frame with a washer, nut and threadlock on the back. I fitted the mounts to the panels on the bench so they are a flush fit but i don't think overtightened, then i glued the whole thing to the roof with Sikaflex 252 - it was easier to put the glue on the bottoms of the mounting and then let gravity and the weight of the panels bed them down onto the fibreglass roof.
Panels were mounted one evening in the summer with a reasonably high ambient temperature but not direct sunlight, so one possibility is thermal expansion/contraction of the panels in direct sun or overnight cold. Should i have left some sort of gap/padding between panel and mount to allow some amount of movement?
Its only been driven a few KMs at low speed so far but with a lot of swaying and bouncing, so whilst it could be movement and flexing of the whole setup , its not likely to be wind load - but obviously that would become an issue at high speeds.
Its now extremely difficult for me to reach the panel mounts in the centre line of the roof as its high up and i have limited reach on my stepladders. I'd also be concerned about trying to cut through the adhesive and doing damage to the fibreglass roof to remove the mountings, so my inclination is to leave them in place to support the weight of the panels, as long as they are not going to damage or crack the panels by constraining them round the edges and corners, and to tie the panels down to the roof with some more angle brackets, possibly aluminium angle, probably made from woven fibreglass tape which is strong in tension and would probably give a better bond onto the roof using the same Sikaflex 252 - my understanding of aluminium is that even with intensive cleaning its still a bugger to glue reliably.
Thoughts and suggestions please...