Riv Nuts in Fiberglass Top?

[BCam]

Update: I finally got the solar panel mounted. I made brackets out of aluminum angle which I bolted to SS riv nuts in the panel frame with 1/4 x 20 SS bolts.

I adhered the mounting brackets to the fiberglass top with 3m VHB 4960 tape. I also used VHB to adhere the wire entry box. I'll waterproof the flange of the entry box with Eternabond tape. Note: The relative size of the entry box is exaggerated by the camera lens' perspective.

Mounting the panel was a bit of a project since once the brackets are down, they can't be re-positioned.

After the panel was mounted, I tested the bond by lifting the edge of the panel. I'm guessing I applied about 20 lbs of force and there was no sign of any movement or failure of the VHB tape. Time will tell but, based on what I've read, I don't expect any problems.

[ConnieKat]

BCam,
Thanks for the info! My top looks quite a lot like yours, except the high ridge doesn’t go quite as far
forward. I have zero desire to put holes in the top of my van, and still envision any kind of roof rack flying off at speed! I have seen it happen many times....too
many to be “ comfy” with a rack of top of a roof like we both have.....so think I’ll be following your plan.
Thanks for the info!
ConnieKat

[BCam]

Originally Posted by ConnieKat

BCam,
Thanks for the info! My top looks quite a lot like yours, except the high ridge doesn’t go quite as far
forward. I have zero desire to put holes in the top of my van, and still envision any kind of roof rack flying off at speed! I have seen it happen many times....too
many to be “ comfy” with a rack of top of a roof like we both have.....so think I’ll be following your plan.
Thanks for the info!
ConnieKat

Glad I could be of help. PM me if you need any specific help. The toughest part is getting everything positioned for the VHB tape since it can't be repositioned.

My recommendation is to test fit everything. Mark out the spots on the roof where the brackets will be, lightly scuff the area with fine sandpaper and clean with acetone. Do the same with the bottom of the brackets. If you don't want to sand your fiberglass, you'll probably be OK with just the acetone.

Then, with your brackets loosely attached so they can swivel to match the roof profile, put the VHB tape on the brackets and remove the protective film. Then, position two sticks on your roof (one at the front, one at the back) so as to raise the panel enough to keep the brackets off the roof. Carefully position your panel on top of the sticks and, once you're sure everything is right, remove the sticks one at a time and press down the brackets. Ideally, use a rubber roller to apply pressure but I found that a rubber mallet worked as well. Once everything is adhered, you can tighten the brackets to the panel.

If you do have to remove the VHB tape, here's a video on how to do it:

https://www.youtube.com/watch?v=KEbOheeHe3A

There are other methods as well, just Google "VHB tape removal"

[DosMars]

Wow, that 3M tape is expensive! Where do you get yours and is it a better deal than what a quick google-search is showing me?

A few years ago, we ran into a couple from Britain down in Baja. The guy had built himself one of those huge earth-roamer type trucks you see out there on a German 4x4 firetruck chassis. He and his girlfriend had taken a year off to have it shipped over to Canada and were in the process of driving it down to the tip of South America, then shipping it over to Africa for the drive home. Fun trip!

He designed the whole camper in cad and had all the panels pre-made out of refrigerator truck panels. Looked like some type of sheet PVC material sandwiching an inch or two of insulation. I was looking at how he put it together. He pulled out a tube of caulk and told me "You Americans are in love with screws and nuts and bolts. The French Airforce uses this stuff to glue together their aircraft. Holds everything together, has a little give so nothing 'rattles apart' and if you have to take it apart, just run a piano wire through the joints"

I was impressed so he gave me a tube. I need to track it down in the garage, I have a couple of solar panels it would be perfect for.

[BCam]

Originally Posted by DosMars

Wow, that 3M tape is expensive! Where do you get yours and is it a better deal than what a quick google-search is showing me?

I didn't need much to mount my panels only about 4' of 1" tape for each panel (four 6" x 2" aluminum angle brackets) so it didn't seem overly expensive ($22 for 15'). I'm sure there are industrial suppliers selling larger quantities at lower prices if you need a lot. Here's what I bought:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Steve Hunt]

I don't know specifically about this model tape but do know that 3M makes double sided tape more than up for the task.
I use to deal with custom enclosure manufacturers for outdoor industrial equipment that had to survive 200 mph wind test for Florida hurricane ratings and all the panels were held with 2 sided tape.

Originally Posted by BCam

Update: I finally got the solar panel mounted. I made brackets out of aluminum angle which I bolted to SS riv nuts in the panel frame with 1/4 x 20 SS bolts.

I adhered the mounting brackets to the fiberglass top with 3m VHB 4960 tape. I also used VHB to adhere the wire entry box. I'll waterproof the flange of the entry box with Eternabond tape. Note: The relative size of the entry box is exaggerated by the camera lens' perspective.

Mounting the panel was a bit of a project since once the brackets are down, they can't be re-positioned.

After the panel was mounted, I tested the bond by lifting the edge of the panel. I'm guessing I applied about 20 lbs of force and there was no sign of any movement or failure of the VHB tape. Time will tell but, based on what I've read, I don't expect any problems.

[DosMars]

Do you remember what specific 3m tape was handling the 200 mph winds? I got lost on the 3m site tape section!

[Steve Hunt]

Originally Posted by DosMars

Do you remember what specific 3m tape was handling the 200 mph winds? I got lost on the 3m site tape section!

Sorry, I don't its been years since touring their shop but it was common usage and huge time saver. I'd give 3M a call, I'm sure they offer help with product selection...or a distributor of theirs may be able to speak to selection. Great application for the product since who wants to drill a hole in the van roof!