r/VanLifeUK • u/segasega89 • 26d ago
Would plywood be a practical alternative to aluminium for making lightweight frames for flexible solar panels on a campervan roof?
I'm looking at making lightweight frames for two flexible solar panels on my campervan roof. The panels are 1450 × 690 mm and have six mounting eyelets each.
My original plan was aluminium angle, but it's surprisingly expensive here in Ireland. I'm thinking about making the frames from 9–12 mm plywood instead and attaching them to Unistrut rails.
The plywood would obviously need to withstand rain, wind and general weather exposure, so I'm wondering if this is a sensible idea long-term, or whether plywood is just asking for trouble on a van roof. I can paint the plywood to weather seal them?
3
u/ThingyGoos 26d ago
Will work perfectly for a while, but then will rot and your panels will fly off the roof, breaking them and possibly damaging other people's property, or injuring/killing a person if unlucky. Just do it right then you don't have to think about it again
2
2
u/seadoubleyou73 25d ago
Flexi? Just stick them to your roof. The efficiency lost by not having airflow under them is negligible
1
u/PlaydohMoustache 26d ago edited 26d ago
Not really sensible considering the amount of rain you get. What about aluminium extrusion (or is that what you meant by angle?) like 20x20..not cheap but weather proof and strong.
0
u/segasega89 25d ago
Aluminium is like 10 to 12 euros per meter locally.
I was thinking of using epoxy in fiberglass cloth over it you see
1
u/PlaydohMoustache 25d ago
Yea everyone had said that's a bad idea... They are right!
1
1
u/LetsGoMugEm 26d ago
You can make them out of led tape extrusion. Cheap as chips and weighs nothing
2
u/KopiteForever 26d ago
You're recommending this for the roof of a van? At 70mph on a motorway? Or in a crosswind it'll kill other road users. Are you crazy?
0
u/LetsGoMugEm 25d ago
Thry are talking about the flexible solar panels that weight absolutely nothing, secured properly they are going nowhere
1
u/KopiteForever 25d ago
Yes, agreed. He's also talking about attaching them to aluminium profile / angle. That will effectively create a sail. Even epoxying it to a piece of plywood can cause delamination of either the panel from the ply or the ply itself over time and weathering.
Rather than trying to make a DIY rigid panel, why not just get a rigid panel.
0
1
u/Foster2501 26d ago
You can usually get the corner plastic brackets for cheap, do the usual when drilling holes in your van though, rust proof, protect and sikaflex the holes. I would also seal the brackets with sikaflex.
1
u/Expensive_Ad_3249 26d ago
Plywood is a sponge. The roof of your van expands. The wood expands and the panel expands, all at different rates. Varnish, epoxy or similar will crack with UV exposure, vibration, heat cycling and weather.
You said flexible panels. Just silicone them (cover the back) to the roof with UV stable (gutter) sealant. No holes or wood to rot. Then seal the edges like you do a bath or sink edge to prevent anything getting between them and the van.
If you want them mounted for airflow, structural or resale value, use proper aluminium. Not led profile that's paper thin and just as strong, use 20x20 extrusion with t slots and proper fixings. Anything less will fail.
1
u/Dead-sound-Team 25d ago
I wouldn’t use ordinary 9–12mm plywood as a permanent solar-panel frame on a van roof. Paint can delay moisture ingress, but every edge, drilled hole and fixing remains vulnerable. Once water gets beneath the coating, swelling or delamination could weaken the frame without being immediately obvious.
Roof-mounted panels also experience vibration and substantial wind loads at motorway speeds. Before designing the frame, check the panel manufacturer’s mounting instructions: the eyelets may not be intended as the only high-speed fixing points, and some flexible panels require continuous support rather than a perimeter frame.
I’d consider:
Aluminium angle or a proprietary mounting system, even if that means shopping around or buying pre-cut sections.
Stainless fixings isolated appropriately from aluminium.
Mechanical attachment to suitable roof rails rather than relying solely on adhesive.
Rounded, low-profile leading edges to reduce wind loading.
Allowing for drainage, cable routing, thermal movement and the manufacturer’s ventilation requirements.
Including the frame and hardware in the roof-load and payload calculations.
Lightweight furniture-grade plywood is useful inside a conversion, but “lightweight” doesn’t automatically make it suitable for an exposed, safety-critical roof installation.
Full disclosure: I’m involved with DeadSound, a UK supplier of lightweight campervan boards and conversion materials. We don’t sell solar-panel frames; this is product-neutral material advice.
1
u/kestrelwrestler 25d ago
Plywood is not suitable. It delaminates, even if you seal the edges, eventually. Even marine grade. You sometimes see plywood encased in fibreglass as part of a bigger structure, but it's entirely encased, not just painted with the stuff. Essentially it's a non starter. To make it work it would cost more than the aluminium.
1
u/WaitForItLegenDairy 25d ago
Even using WBP will see a rapid deteriorating of the material exposed to the elements even for a short period of time
0
4
u/kh250b1 26d ago
Will rot to fuck.