Mounting Kinetic Rails

[BernHavoc]

Hi everyone,

We are upgrading our solar, and I am unsure of the best way to mount the kinetic rails to the bus's roof.

We have four sections: the kinetic mounting rails of 7' 8" rail and four 72C panels.

I would hate to have the panels fly off as we drive down the road. The bus's roof is tongue and groove, and I would like to find a way to mount the panels without dismantling the interior.

Thanks!

 

[Rucker]

There are options beyond through-bolting, though there are strong opinions about some options.

I used standard solar panel aluminum L-brackets that I secured with VHB and hefty screws. My roof is fiberglass, but I'm pretty sure if you could muckle onto those brackets you could lift the whole bus off the ground without them letting go.

 

[BernHavoc]

Thanks. I have 12 L Foot brackets (so three per rail). I wasn't sure what kind of screws I should use. I had thought about some type of glue. Would the VHB tape be a better option? My one concern would be the extreme cold, the bus will be in northern Canada in the winter, and it can get down to -40, I wonder how that would affect the tape.

 

[Rucker]

Thanks. I have 12 L Foot brackets (so three per rail). I wasn't sure what kind of screws I should use. I had thought about some type of glue. Would the VHB tape be a better option? My one concern would be the extreme cold, the bus will be in northern Canada in the winter, and it can get down to -40, I wonder how that would affect the tape.

You'd have to check the specs on VHB. My guess is the stuff is pretty good over a wide temp range.

Ironically I ran into a link where this guy is using VHB in exactly this application:
https://www.rvtravel.com/video-mount-rv-solar-panels-2209/

I think this article has been kicking around for a bit.

 

[Danjo-SKO]

I don’t know why through bolts are a big deal. I haven’t had any leaks.

 

[Rucker]

I don’t know why through bolts are a big deal. I haven’t had any leaks.

I think he's just trying to avoid taking down the shiplap ceiling on the inside.

 

[Rucker]

Thanks. I have 12 L Foot brackets (so three per rail). I wasn't sure what kind of screws I should use. I had thought about some type of glue. Would the VHB tape be a better option? My one concern would be the extreme cold, the bus will be in northern Canada in the winter, and it can get down to -40, I wonder how that would affect the tape.

Preferred method seems to be through-bolt.

Next would be VHB and screws. My roof is fiberglass and I did a bunch of tests with pilot holes and sheet metal screws to get the right grip without cracking the fiberglass.

Last would be VHB only. The problem I see with a metal roof is the VHB adheres to the paint, not the metal, so as long as the paint is bonded well, no chalking, it should be fine providing there's sufficient surface area bonded.

Note that VHB is not UV resistant so put a layer of Eternabond or such over any exposed edges to reduce the risk of degradation over time.

 

[Danjo-SKO]

I think he's just trying to avoid taking down the shiplap ceiling on the inside.

Stainless carriage bolts aren’t too ugly

 

[rossvtaylor]

I cut mounting brackets, to which the IronRidge rails bolt. The brackets are roughly shaped like an inverted T that I bend...and I'll take, and post, a photo of one tomorrow. The base plate on mine is large enough so that I can get plenty of adhesive bond - and I use 3M 5200 for that. I've pull tested this bond to 2000 pounds, without any sign of failure. Additionally, the plates have two 1/4-inch holes which are spaced to align with the flanges on the ribs.

To install these, I place the bracket over a rib (using the rivets for positioning, to show me where the rib flanges are). I mark the perimeter with a Sharpie, then I use an aggressive sanding disk to flatten any rivets which are in the way and to sand down through the paint and coatings to bare metal. I then mark and drill the two holes for the rivets, apply a good layer of 5200, put the bracket in place, and rivet it down with two 1/4-inch closed-end stainless rivets.

All of this is done from the top, so it would work fine for you.

 

[TJones-SKO]

You could install rivnuts into the sheetmetal directly over the ribs in roof. Place the rivnuts between the two rows of rivets that attach the sheet metal to the ribs. Use the size rivnut and bolt intended for your L brackets.

Ted

 

[Rucker]

I cut mounting brackets, to which the IronRidge rails bolt. The brackets are roughly shaped like an inverted T that I bend...and I'll take, and post, a photo of one tomorrow. The base plate on mine is large enough so that I can get plenty of adhesive bond - and I use 3M 5200 for that. I've pull tested this bond to 2000 pounds, without any sign of failure. Additionally, the plates have two 1/4-inch holes which are spaced to align with the flanges on the ribs.

To install these, I place the bracket over a rib (using the rivets for positioning, to show me where the rib flanges are). I mark the perimeter with a Sharpie, then I use an aggressive sanding disk to flatten any rivets which are in the way and to sand down through the paint and coatings to bare metal. I then mark and drill the two holes for the rivets, apply a good layer of 5200, put the bracket in place, and rivet it down with two 1/4-inch closed-end stainless rivets.

All of this is done from the top, so it would work fine for you.

Now THAT is the definitive mounting solution!

I believe the above mounting solution also enables the bus to carry a space shuttle back from California to Florida.

 

[BernHavoc]

Thanks, everyone. I picked up some additional L feet, 3m 5400. I think I will glue the L-feet and then use a carriage bolt as suggested. I would hate for the panels to fly off and hurt or kill someone.

It is a 1998 Thomas MVP S T Liner. Is there any wiring I should be worried about in the roof? My mind always goes to the worst-case scenario haha.

 

[Danjo-SKO]

I used neoprene-backed fender washers and Sikaflex 521. After the bolt is through the hole put a healthy bead of sealant and then the washer. Then a little more sealant and then the bracket. I used nylock flange nuts which might deteriorate in the sun. Later I found some flange nuts with an indent in the lip to make them lock. I think they are distributed by Hillman.

 

[HamSkoolie]

VHB is great but it's NOT a proper mounting material (alone) for ANY installation that's going to be going down the road with a great big flat sail just waiting for the right wind conditions to fly off and KILL someone behind the rig.


Use through bolts or multiple Rivnuts through hat channel (not just sheet metal). Through bolts with large "washers" to spread the load might be acceptable for through bolting through just the sheet metal but none of us are engineers so who knows. On a flat surface probably fine, on a curved roof? Hmmmmm


We will be mounting a steel tube rack from outer side wall to opposite side wall with uprights at hat channels and two supports inboard. Outside uprights will be through bolted and rise vertically in the plane of the sides. Inboard supports will also be through bolted. All bolts and nuts will be grade 5 or higher and we've checked the tensile and shear specifications to ensure that the hardware is sufficient.



NEVER use the cheap un graded hardware so common in hardware and big box stores. It's ungraded and that means unknown specifications.