Community Forums

mj6599 · 09-01-2020, 02:53 PM

I am getting ready to install solar system on my new to me DP I am looking at 2 255 watt Sainty Solar panels off craigslist here. I am considering using a renogy 40 MPPT rover elite controller. I put a system on my old FW and I went all out on that but trying to save a buck. If you have any of the panels or controller would like to here your thoughts

I was wondering the best method for installing panels to a fiberglass roof. Do you just use the 3M 2 sided tape and some Dicor or should I put a screw in the brackets and Dicor. I have watched some installs on you tube and same of them say the 3M tape is enough but I want to make sure. What has people who have fiberglass roofs done?

A32Deuce · 09-01-2020, 04:49 PM

I drilled a small starter hole, put Dicor down, set the mount over the Dicor and screwed them tight. Do Not over tighten! Then I put Dicor over top and around the brackets on the roof. That was back in 2012 and 80000 miles ago. There is about an inch air gap under them to help cool the panels.

vsheetz · 09-01-2020, 05:15 PM

Same here.

Quote:

Originally Posted by A32Deuce

I drilled a small starter hole, put Dicor down, set the mount over the Dicor and screwed them tight. Do Not over tighten! Then I put Dicor over top and around the brackets on the roof. That was back in 2012 and 80000 miles ago. There is about an inch air gap under them to help cool the panels.

UTTransplant · 09-01-2020, 08:29 PM

Quote:

Originally Posted by A32Deuce

I drilled a small starter hole, put Dicor down, set the mount over the Dicor and screwed them tight. Do Not over tighten! Then I put Dicor over top and around the brackets on the roof. That was back in 2012 and 80000 miles ago. There is about an inch air gap under them to help cool the panels.

And yet a third. 25,000 miles, Arizona desert to Iowa winters. Still in good shape.

geordi · 09-01-2020, 08:49 PM

If we are talking about using the black plastic corner-and-side supports that raise the panels... I've used them too on my Monaco. I actually only used the corners on two panels, and the middle brackets (total of 4) on the third panel b/c I have a slightly arched roof and the panels are across the roof rather than on one side or the other from the middle. No way to fit them front-to-back b/c of obstructions.

Anyway - they are above the roof by about 1-1.5 inches which is good for ventilation, and I used lots of 100% GE Silicone 2 as a "glue" for the mounts plus about 4 pre-drilled holes in each bracket with screws and coated with a bit of silicone for protection. Several years and thousands of miles and they are doing fine.

jcussen · 09-03-2020, 10:23 AM

I used VHB tape on the bottom of unistrut, with a self tapping screw on each end, just in case. I then attached the solar panels to the rails with regular unistrut fittings. I try to use the longest piece that can fit, allowing for further expansion or panel changes.

cruizerEd · 09-03-2020, 10:35 AM

I am assuming you have a fiberglass roof.

I have 12 panels held down with 3M VHB tape.

There are a lot of different VHB tapes so don't just get VHB.

We used stainless steel angles that had a foot a 1" wide and 2" long.

Most of them have held up fine through 5 years of continual use. The few that didn't were not installed properly because the foot wasn't properly square to the roof and add preload to the installation. Even those held but about 1/2 the tape let go.

Be very careful to clean the roof getting all of the oxid off and any wax.

Do not use Dicor on your roof. Winnebago uses a silicon based product Nuflex 311 it comes in self leveling and regular caulk. From what I have seen on Dicor roofs Nuflex holds up a lot better.

I am experimenting with not using the Nuflex on a few of the feet to see how that effects their performance. The reason is for inspection. Without the sealant it will be easier to see if they are letting go.

As for screwing it seems almost pointless. There is so little for a screw to hold onto and all those holes are bound to leak.

mj6599 · 09-03-2020, 12:57 PM

Quote:

Originally Posted by geordi

If we are talking about using the black plastic corner-and-side supports that raise the panels... I've used them too on my Monaco. I actually only used the corners on two panels, and the middle brackets (total of 4) on the third panel b/c I have a slightly arched roof and the panels are across the roof rather than on one side or the other from the middle. No way to fit them front-to-back b/c of obstructions.

Anyway - they are above the roof by about 1-1.5 inches which is good for ventilation, and I used lots of 100% GE Silicone 2 as a "glue" for the mounts plus about 4 pre-drilled holes in each bracket with screws and coated with a bit of silicone for protection. Several years and thousands of miles and they are doing fine.

are you talking about these
https://www.renogy.com/corner-bracket-mount/

leadman · 09-03-2020, 01:14 PM

I have 7 Renogy 100 watt panels on the fiberglass roof of my Winnie. I used the Renogy brackets and stainless screws they sell. I also used a caulking tube adhesive I bought at the RV store. Not at home so can't go look at the name.
I drilled the holes for the bracket and filled with them with adhesive then covered the bottom of the bracket with adhesive and installed the bracket and screws. I then covered the entire top of the bottom foot with adhesive.
No problem in over 3 years and I have been in some high winds (70mph) while driving on the freeway.

johninsd · 09-03-2020, 01:41 PM

I put my two 100 watt renogy panels on the roof with the VHB tape mounts sold by AMSolar. 18 months and 7,000 miles so far - they haven't budged. Main thing is to get the area clean, swabbing the area with alcohol and getting the tape pressed down firmly and flat on the roof. I did tie some rope to eyebolts attached to the panels and looped the ropes around my air conditioner - so even if a panel were to let go the rope would keep it from flying off - might do some damage flopping around in the breeze but won't fly off and hit the vehicle behind me. I only had to drill two holes in the roof for the cables instead of 16 holes for the screws plus the two for the cables. Covered the cable entry with a plastic cover, glued that down with a marine RTV, again no screws used. It's also still quite firmly stuck to the fiberglass. I go up a stepladder next to the RV once in a while to check - so far so good. This is on a 2106 Itasca Navion "G".

geordi · 09-03-2020, 10:17 PM

Quote:

Originally Posted by mj6599

are you talking about these
https://www.renogy.com/corner-bracket-mount/

I got mine from Amazon, but yeah, that's the product. They work well.

dieselclacker · 09-04-2020, 06:31 AM

I used mounts and 3M VHB tape purchased from AM Solar. No screws just the VHB holding the two 100 watt panels to the fiberglass roof of our motorhome. I installed them myself 12 years ago. The 3M VHB is amazing product!!! Highly recommend AM Solar company for products and information regarding solar power for your RV.

mj6599 · 09-04-2020, 06:13 PM

Ok I found 2 brand new 300w panels for $300 so I went with them. I am thinking now that I should go with a 60 amp controller or would a 40 still if I remember the 40 had a 600w max. Also on the batteries I have 4 12v is the pos hooked up at one end and neg to other? It's been awhile since I did solar. May just make my own brackets as I did for my last set up

leadman · 09-08-2020, 07:25 PM

I would go with the 60 amp controller. Don't like running electrical items maxed out.
I hooked my batteries up as you described, pos on one end, neg on the other. No problems.