Solar panel sticky stuff. A test.

[MacroMad]

If you are at all worried about "glue'ing" things to your "Van" be it roof or rear etc remember that flat surfaces will stick together without any glue at all, even two wet surfaces will stick together.
The larger the area the better, so when you introduce an adhesive manufactured for sticking things down / together between those flat surfaces it works pretty well.
Again remember that some PU products need a cleaner and a primer, some people scoff at this measure as another attempt to get money out of you but the cleaner is to clean the surfaces and the primer is to etch into the surface and activate with the adhesive to form that better bond.
I have been"Glue'ing" or Bonding surfaces together for 40 years where peoples lives depend on that bond and have seen many examples of "bonding" where cleaners and primers have not been used where they should have been, you could literally pull the bonding material away from either surface.
If you are using any supplied brackets that do not have a large surface area, bolt them to something that does have a large flat surface area and bond that to your roof / rear, y6ou can then take it off when it suits you without any difficulty.
Apologies for the long boring reply.

 

[chenderson1965]

Ok. Now I'm worried. I'm about to take on my own project to add a 150w panel to my roof. It will have to go transverse (long edge facing forward) and about 150mm from where the roof starts to curve down towards the window. I'm planning to use edge supports as well as corners.

Don't really want to put screws through the roof unless I have to, so which adhesive should I use for plastic brackets and a painted aluminium roof (it's an N&B)? There seem to be about 10 types of Sikaflex before you look at any others and they mostly seem to claim to do the same thing!

Does something like Sikaflex require an etch primer as well as really good cleaning of the roof before fixing?

Thanks

Chris

 

[petermayson]

I decide to install solar panels too. Just interesting how to calculate cost them.

 

[Al n Val]

this is my install completed yesterday

I ordered the end deflector/mounts longer than needed at 68cm and cut down to 515cm needed to span the panels width. I then used the offcuts down the panels length for A. more fixing area and B. as it’s a long panels gave it better rigidity.

Victron Smart Solar MPPT controller completes the install and no connection to the Sargent unit so keep this and the original solar installation completely separate

Al

petermayson

i’d fit as large as you possibly can

 

[petermayson]

I decide to install solar panels too. Just interesting how to calculate cost them. I also recommend reading this article https://websolarguide.com/solar-pool-heater/

Seems interesting.

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[Arty fjr]

Do you think the shape of the roof would make much difference .i have a low top as there is only the boss and I .my roof is at nearly the same angle as the wind screen so i am thinking going along most of the wind would be over the top of the panels.

 

[Arty fjr]

I decide to install solar panels too. Just interesting how to calculate cost them.

I just bought this kit via ebay but alas a new be to all this aswell

 

[Gromett]

Do you think the shape of the roof would make much difference .i have a low top as there is only the boss and I .my roof is at nearly the same angle as the wind screen so i am thinking going along most of the wind would be over the top of the panels.

If the wind is pushed up it creates a low pressure zone just behind the lip of what is pushing it up. If your solar panel is within this low pressure zone it is possible that it will suck air from underneath the solar panel causing a pressure differential (not a vacuum). So even if the top of your solar panel is not in the direct stream of air it could develop lift. Without a wind tunnel or more details it is hard to give definitive advice

The only scientific fact regarding this is simply this. If the air is moving faster over one side than the other lift will be developed proportional to the difference in pressure caused by the speed difference.

Yup, Had a few beers

I personally suspect that the vast majority of people will be ok with just an adhesive mount. But if the paint isn't bonded to the metal correctly, or the surface is contaminated or ill prepared then there will at some point be a flying solar panel.

I always prefer to over engineer things. Having 2 levels of safety is my preferred minimum. I glue and screw because I don't trust the screws and I don't trust the glue. Screws rust and corrode, Glues can chemically or physically fail. The roof is an unforgiving place, Hot and Cold. Direct and sustained UV bombardment. Chemicals in the air, Salt water and much, much more. Belt and Braces is used to mean ill designed/engineered. I prefer to think of it as being safe to prevent your trousers falling down

I have heard of at least 3 stories of people on FB wondering where their solar panels were. The usual response is check the route you took, it is more likely you didn't fit them correctly than they have been stolen.

 

[Diabalo]

I never realised we had so many rocket scientists on fun

 

[walburga]

I've fitted solar panels to 3 previous vans, made my own brackets using aluminium I scrounged from the scrapyard. Always made sure I had a 3mm gap underside of bracket to van roof using tile spacers. I drilled several holes in the brackets which allowed the mastic adhesive to 'bleed' up and create more 'stiction', also showing that it had satsfactorily spread.
Always tried to move the panels when on the roof cleaning...they're going nowhere.

Allen

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[McLouis]

A lot of folks seem to be thinking of using Sikaflex 512, that's an adhesive sealant. Sikaflex 252 is the structural adhesive and is recommended by Sika (slideshow on website) for Solar panel fixation. But as mentioned by MicroMad I think it was, the key factor is to use the appropriate activator and primer, these are the belt to the sika braces. If folks whinge about the cost of Sika products then the primer really makes your eyes water, but that is how the system is designed to work. Without it its like screwing a screw into plasterboard without a suitable winged plug.

 

[tkk]

Not an expert on adhesives but a test of bond strength at installation probably doesn’t reflect the situation after long term exposure to vibration, expansion /contraction etc. I’d say if relying on adhesive alone regular inspection/testing advisable.