Best adhesive to mount solar panels with?

Just a follow up on Glue strength, here is a forklift destruction test video, would apply to any 3MPa glue. As long as you prep the surface fairly well this stuff never comes off.

 

Neil

Observer
I have always been a great believer in Sikaflex Adhesives.
However, I just bonded some solar panels on with an adhesive called CT 1 ( in the UK )

I am pretty impressed.

Its very tough.

Neil20201009_160710.jpg
 

Neil

Observer

I would suggest that it was probably badly fitted.

Either it was the wrong sika , some varieties are only sealants and not adhesives.

Or the plastic mounts had grease or weren't keyed up correctly .

Looking at the remaining sika on the roof it has obviously had moisture getting under it, it looks black and mouldy.

If used correctly , You should never lose a panel that is securely mounted with Sika alone. Provided it has enough footprint and the glue hasn't been squeezed out when mounting it.

I have never liked the plastic pre molded mounting kits. They simply don't have enough footprint for adhesive alone. I always make my own mounting brackets from 50mm aluminium angle. Each bracket is at least 250 mm long and on a big panel I would use 8.

I have just removed 2 such brackets from the roof of a camper. It took me over 1 hour each. They were fitted in 2005.

Thats a lot of adhesive and no holes in the roof

Neil
 
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dman93

Adventurer
I’m no expert, but as an engineer, two comments on the calcs, picked up from colleagues who did wind tunnel testing of vehicles. First, as someone else noted, the uplift from passing vehicles or just air going between the roof and the panels. That pressure is now acting on a much larger surface area. Second, you also need to consider crosswinds, and the resultant forces, again acting on more than the pure frontal area. The velocity of a vehicle going down the road, relative to air drag, is never aligned with the ground speed direction.
 

Motafinga

Adventurer
Add me to the 3M VHB club, I have 2x 100 watt rigid panels attached directly to my roof by the frames of the panels ( no brackets) My reasoning being there is zero gap for any air to enter and create a sail effect. I did go around the sides with a few L brackets / angle though just to add more surface area. Been up there for several years and many a hard mile.
 

ovʀʟxnᴅ

Member
I've used 5200 for years, but never tried it as an adhesive. It self-levels, so get a feel for it before you go crazy with it. Also, it only survives direct UV for maybe 5 years or so before beginning to chalk and degrade.

You might get better answers from the manufacturers by not telling them what you're installing, just that your bonding X metal to Y substrate.
 

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