Mounting solar panels.

ballast2 · Guru

Mounting solar panels.

iana · Guru

I did this, didn't want to put holes in the roof. Our van has a fiberglass roof, and planed to glue the mounts to it, as per the instructions on the Sikaflex web site. I purchased the mount kit, comprising of four corner mounts and two middle mounts. I got six pads made up of fiberglass, and screwed the mounts to these. Then glued the pads to the roof. I used pads to increase the glued surface area.

ballast2 · Guru

iana wrote:
I did this, didn't want to put holes in the roof. Our van has a fiberglass roof, and planed to glue the mounts to it, as per the instructions on the Sikaflex web site. I purchased the mount kit, comprising of four corner mounts and two middle mounts. I got six pads made up of fiberglass, and screwed the mounts to these. Then glued the pads to the roof. I used pads to increase the glued surface area.

Thank you.

Cheers

T1 Terry · Guru

We mount the solar panels to 70 x 30 aluminium angle using rivnuts in the panels and 6mm stainless bolts or countersunk screws if clearance is an issue. Then we put the solar panels mounted onto the tall side of the aluminium angle on the roof, draw out the angle outline on the roof, then lightly sand the roof inside the lines. Rough up the underside of the aluminium angle with an angle grinder, clean both faces with metho and once that has evaporated, apply a bead of Selleys Armourflex just inside the edges of the drawn ot line or the edges of the aluminium, fill in the bit in the middle with a wiggly line of adhesive and apply one to the other. 6 or 8 plastic 2 ltr milk bottles filled with water placed on the panel along the edges will hold it down while the glue dries, a finger dipped in metho to smooth the outer edges of the white glue and the job is done for the day. Next day, undo the screws/bolts attaching the panels and add some more glue to any bits that the glue didn't squeeze out along the inside edges, connect up the solar cables and bolt them back on, job done. the only way you will get that Armourflexed aluminium angle bck off the roof is to cut the Armourflex with a knife attachment in a multi tool. the roof will come off before that aluminium lets go and it spreads the weight nicely across the roof so it will cross the roof beams some where. No holes in the roof to leak yet you can easily remove a panel for cleaning or maintenance. Been doing this for 10 yrs, used Sikaflex 11FC before, but the Selleys Armourflex is a better adhesive and does not powder when exposed to the sun like Sikaflex 11FC does, so it doesn't erode away over the yrs and doesn't let go when it gets hot like 11FC does.

T1 Terry

Mamil · Senior Member

On mine I used the ABS mounting brackets which can be bought from Jaycar, or a bit cheaper on the internet, and glued down with Sika 291. Holds them down firmly as they have a large surface area pad on the bottom, and raise the panels up the right amount to give space for air flow under to increase the output of the panels. Just be careful there's a lot of similar mountings being sold on Ebay that are made of Polyethylene which adhesive/sealants will not bond to, and are an accident waiting to happen!

IMG_20190316_143931 - small.jpg

Also suggest using a proper cable entry box with glands where the cable enters the roof, I used one that doubles for both the TV antenna and solar cables to minimise penetrations.

Cable entry small.jpg

Buy the glands with two hole rubbers from specialist electrical supplier to seal the twin solar cable properly.

Gland rubber small.jpg

-- Edited by Mamil on Sunday 6th of October 2019 01:33:22 PM

Grandad5 · Senior Member

Mamil wrote:
Also suggest using a proper cable entry box with glands where the cable enters the roof, I used one that doubles for both the TV antenna and solar cables to minimise penetrations.

Buy the glands with two hole rubbers from specialist electrical supplier to seal the twin solar cable properly.

You mention JayCar for the solar mounts but a generic terminology for the entry boxes. I tried the JayCar site with no luck.

Can you suggest a search phrase for me or better yet, the name of a supplier please?

Jim

Grandad5 · Senior Member

Terry, how would you handle a curved roof? Just two lengths of aluminium perhaps? Also, wouldn't a continuous run of the 70x30 angle negate any possibility of airflow under the panel?

Jim

Mamil · Senior Member

Grandad5 wrote:

You mention JayCar for the solar mounts but a generic terminology for the entry boxes. I tried the JayCar site with no luck.

Can you suggest a search phrase for me or better yet, the name of a supplier please?

Jim

There is a cable entry box on the Jaycar site https://www.jaycar.com.au/white-abs-solar-cable-entry-point/p/HS8866

Mine was similar but from Ebay, can't remember which seller as it was a couple of years ago now, but entering "solar cable entry box" into the Ebay search box brings up lots to choose from.

Note that most of them have two small (20mm I think?) single entry glands for you to split the twin solar cable between. I used one of these for my TV antenna cable and drilled the other hole larger to fit a 25mm twin gland for the solar cable. From memory the Jaycar box is too small to fit a larger gland, which is why I bought a slightly different one from Ebay.

Finally, don't follow my example for mounting it! You should orientate it so the sloping face is pointed towards the front of the van and the glands are on the rear, for maximum weather protection while travelling. I only did mine sideways because my TV antenna cable was already cut too short to do it any other way!

-- Edited by Mamil on Sunday 6th of October 2019 08:53:54 PM

ballast2 · Guru

Thank you.

Cheers.

Grandad5 · Senior Member

Thank you Mamil

T1 Terry · Guru

Grandad5 wrote:
Terry, how would you handle a curved roof? Just two lengths of aluminium perhaps? Also, wouldn't a continuous run of the 70x30 angle negate any possibility of airflow under the panel?

Jim

The roof will be relatively flat in one direction, either across or front to rear. The 70mm high aluminium angle creates a 40mm gap under the panel and natural air flow will occur as the hot air escapes and the colder air replaces it. There is still an issue with the hot air directly under the glass part being trapped by the solar frame, so flat mounted panels need the side frame to be as narrow as practical to minimise the amount of air trapped by the skirting effect of the frame. I've even seen holes drilled in the end sections of the frame to allow the hot air to escape, but you need to get those holes large enough for air to flow easily and as close to the under side of the glass without actually touching it with the drill or hole saw. If you hit the glass with the cutting each it will shatter, so measure twice, drill/cut once wink

If the aluminium run is long and there are dips in the roof, I put a bit of 3 ply under the aluminium at the lowest point of the dip and remove it before the glue dries so it allows the water to flow under the aluminium to a path for it to drain away.

T1 Terry

Grandad5 · Senior Member

Thank you Terry.