One Or Two? (1 Viewer)

[A S R]

I have a nice shiny new HUGE 6’ wide solar panel and a load of new mounts for it. BUT, do I use 1 or 2 big wide mounts on the long sides? One of these long sides will be facing the wind at the front of my van. There will be 4 corner mounts and two short mounts on the short sides too.

 

[TCG]

Two …belt and bracers

 

[Ian_H]

I think I'd do 2 on the front edge and 1 on the back, so air won't get 'trapped' underneath and try to lift it?

 

[RogerIvy]

What is the width of that panel?

 

[Gellyneck]

Might be worth a read?

Final check before fixing my solar panel to the roof

You can get an actuator for 522 from Sikaflex. Beware, both the 522 and the activator have a shortish useful life and they also need ambient temps of above (best check these figures) 13c and specific application time. Sikaflex website has videos showing correct application methods.

www.motorhomefun.co.uk

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[A S R]

What is the width of that panel?

 

[RogerIvy]

Firstly I wouldn't use those acrylic brackets. The surface area on the roof is too small for my liking. Just personal preference. They also take up a lot of space increasing the effective length and width.

I would use aero brackets:

Aero Brackets for your Solar Panel 67cm long — Offgrid Power Solutions

Product Features The mounts can be safely bonded to the surface, removing the need to drill holes in your caravan, motorhome or boat. The solar panel then slides into the groves and is secured with the endcaps screwing into the side of the panel. Contents 2 x 67cm aero brackets (670mmx105x62mm

offgridpower.solutions

They are 67cm long, so if you use a single bracket at the panel ends you'd have a 213mm overhang. Such an overhang would be fine if the panel is not right at the front because you have a reasonably substantial service area for the sika. You'd screw the brackets to the panels, creating a very solid structure. If the panel could experience very heavy drag (e.g. right at the front) I'd get a 2nd set of brackets and cut to size so I have a bracket over entire front of the panel (joined in the middle - you'd not notice it). If I was mounting the panel sideways and near the front I'd want a lot of bracket!

or I would use 25mm x 50mm aluminium rectangular tubing (1.5mm walls). These you could cut to exact size and have a very strong sika bond to the roof. You attach the bars to the panels with self driller/tapping screws. Works a treat. Very strong structure with substantial sika surface area.

or I would use 50mm x 50mm aluminium angle and screw them to the panel sides with self driller/tapping screws. Again you cut to length. Similar to the tubing, substantial surface area.

Do a dry-fit to mark where the sika will sit on the roof. Clean and scuff the area carefully, water -> isopropyl alcohol -> sandpaper -> sika activator

Your sika should be ideally about 3mm thick. Cut about 20mm off the nozzle so it comes out easily. You'd probably want to use a tube at each end (front and back).

 

[A S R]

If I was mounting the panel sideways and near the front I'd want a lot of bracket!

This is the issue. It’s going to be right at the front and sideways. The whole 6ft length will be side on to the wind. I think I’m going to bin ( sell ) the plastic brackets and get two 6ft lengths of 50mm x 50mm angle aluminium and cover both the long sides fully. That’ll stop any wind getting under the front and trying to lift it up.

Thanks for the tips!

Now, which sikaflex……….
I’ve used this in the past on the panel I put up about 3 years ago and it was a hell of a fight to get them off again.

 

[RogerIvy]

We generally use 522, incredibly strong.
Costs more than EBT but worth it.

 

[A S R]

We generally use 522, incredibly strong.
Costs more than EBT but worth it.

Aah ok thanks.
Would 75mm x 50mm angle aluminium be better than 50mm x 50mm? Or is that total overkill?

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[Lenny HB]

That’ll stop any wind getting under the front and trying to lift it up.

That will create more lift.

Now, which sikaflex……

I always use 291i more expensive but a lot stronger than 522 even better is 292i

 

[RogerIvy]

Aah ok thanks.
Would 75mm x 50mm angle aluminium be better than 50mm x 50mm? Or is that total overkill?

We generally use 50mm x 25mm box section. Most brackets lift the panel 25mm off the roof.

 

[RogerIvy]

That will create more lift.

I always use 291i more expensive but a lot stronger than 522 even better is 292i

Sika do recommend those as opposed to 522.
That said, I’ve never heard of a panel correctly fitted with 522 (and proper roof prep with enough curing time) coming off.