Mounting panels

[Klupduck]

I have a P-30 I'm looking to mount a Renogy 400 watt kit on. My question is, what is the best way to mount the panels on top? Is there a preferred rugged bracket or way that folks have found works best to mount panels on a large, flat topped vehicle, safely and securely? Thanks for any advice.

 

[Matlock]

On my bare aluminum roof I fasten my 100watt panels down with VHB 3M double sided tape.
No mechanical fasteners required or used. I don't like water leaks and living in the NE we get temperature swings from 95* to -15* through the year and always a couple feet of snow, so no holes drilled for any type of fastener = no leaks. Still secure after 6 years.

Notice I said "Bare Aluminum Roof". I wouldn't try my application on any other roof surface, plastic nor rubber nor a painted roof of any material. And do follow the manufacturers recommended preparation before installation.

just my 2¢

 

[Klupduck]

@Matlock Thank you, I honestly would not have landed on that, I was thinking braces on the side, unistrut, and the panels mounted to the unistrut. I appreciate the advice, i'll look into getting my roof buffed out and taping down. I just looked up the tape, that's some serious stuff! I was thinking butyl, but that seems even more heavy duty.

 

[highdesertranger]

VHB tape is very strong. However If the prep work is not done exactly the bond will fail. People have lost their panels on the highway using it. Also there is dozens of different types for different applications, you need to get the right one. Highdesertranger

 

[bullfrog]

I think you will find most panels work better with an air gap for cooling of several inches so standoff brackets need to be considered as well as if you intend to tilt the panels or just use more panels.

 

[Thomas]

I'm also looking at several panel mounting methods for my box truck.  I have an aluminum roof supported by aluminum joists.  I was thinking of putting in light wooden ceiling joists along side the aluminum joists - so I could mount my panels using lag bolts through the aluminum skin and into wood, and later hang my ceiling on those same light wood joists.  The problem with that scheme is that my aluminum joists are 16" on center, but they're about 2 1/4" wide, with only 13 1/4" between them - meaning that I have to cut the edge off a couple of them to make 14" openings for my vent fans.  Cutting into the aluminum joists requires me to support them with wood - so I guess my light wood ceiling joists will be under each aluminum joist, contoured to their curve using a cardboard template (curved roof, flat ceiling).     With all that said, I'm now debating whether to mount panels by drilling through the aluminum joists into the wood joists (pumping the mounting holes through the aluminum joists with Dicor), OR simply putting a strip of 3/4" ply up against the under side of the aluminum roof skin and bolting on panel brackets through that.  I'm leaning towards option B.  So it would be mounting bracket on aluminum skin, on plywood - fill the drill hole with goop and bolt through that sandwich.

 

[highdesertranger]

Lag bolts into wood is a poor option. Much better would be bolts. Highdesertranger

 

[Thomas]

HDR, I was hoping you would weigh in.  Thanks, and I agree.  Bolts through the whole "sandwich" would give me better control over how tight I'm squeezing it, and provides the ability to snug it up without wondering if I'm just stripping the wood.

 

[PlethoraOfGuns]

Step van? Step van! Post some photos! I'm assuming you have an aluminum roof, not a fiberglass. But regardless, be careful with wood. And avoid using steel unistrut due to the bimetal corrosion that will on. Going unistrut? Maybe stainless steel unistrut will do, but you will pay dearly for that. I would stick to either adhesives or carefully chosen mechanical fasteners. Also air gaps are nice. This is what I did:

Got some aluminum self-sealing rivnuts and anchored them through roof into aluminum cross supports underneath roof sheet. These rivnut installer tools can be had for under $100 and can make so many projects possible where you can't get to the other side to get a nut onto. Or for convenience of not having to deal with a nut.

Makes a nice attachment point. Use stainless hardware and sealant on the threads and all around that area. Can never have too much sealant.

Mounted aluminum angle bars to the roof via roof rivnuts. Then used more rivnuts on the panels to secure to the angle bars. Left abut 1" of air gap under panels. Overkill? Maybe, but these panels aren't going anywhere. And I left pace between panels in case I got bore one day and wanted to hinge them.

Mounted all the panels to the driver side to get them out of the gutter side of road where tree branches like to skim the passenger side of roof. And we have half the roof to up there with a few chairs and hangout on nice nights.

 

[Matlock]

I'm also looking at several panel mounting methods for my box truck.  meaning that I have to cut the edge off a couple of them to make 14" openings for my vent fans.   

I mounted my Fantastic fan in the rear wall of my Box Van next to the door.
Your saying "Fans", is the box that big that you want two?

Also someone mentioned space under panels, I agree, my panels are bolted to Z-brackets that come with the panels and those brackets are VHB'd to the aluminum roof. Gives me about an inch of air space under each panel. I only use a 1" x 3" strip of VHB on the four corners of each panel.
So, minimum square inches of cleaned roof to adhere all the panels.
1/16th inch thick VHB peal and stick tape. Has excellent shear and pull strength.

I once considered running a 10' long piece of aluminum angle bolted along both sides to connect all the panels together and through bolt them to the roof. Then I come to my census and go have a beer.

 

[bullfrog]

If you look closely at your panels most manufactures glue the aluminum angle you mount them with to the glass. I would think vibrating down the road I would consider some extra support other than just the supplied Z brackets and possibly some aluminum corner brackets. I didn't do any of that as mine are folded vertical on the back and bolted snuggly against rubber padding while traveling and have been okay in 40 mile an hour winds while parked.

 

[Sofisintown]

VHB tape is very strong.  However If the prep work is not done exactly the bond will fail.  People have lost their panels on the highway using it.  Also there is dozens of different types for different applications,  you need to get the right one.  Highdesertranger

HDR, I bought the VHB tape to mount my panels to the roof.
My roof is steel and painted, so I need to strip the places where the foot of the brackets will attach, down to bare metal , right?
I also bought Eternabond to cover the feet of brackets afterwards, so it will protect them from water and UV.
I wait for days of over 65F for 24 hours , that is the recommended temp/time to cure.
Am I doing it right? :s

 

[highdesertranger]

What type of panels? rigid or flex? Highdesertranger

 

[Bobhdus]

I used these plastic mounting brackets from Amazon. They worked fine. Solar Panel Brackets Black ABS Solar Panel Mounting Brackets 7 Drill-Free Corner Bracket Support Kit for Wood Frame RV Boat Campers Caravans Hood (Corner Bracket,Side Bracket,Cable Entry Gland) https://www.amazon.com/dp/B087CM4P97/ref=cm_sw_r_cp_api_glt_fabc_HTD497Z6MBCJ6RBWKXN3?psc=1


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[Sofisintown]

What type of panels?  rigid or flex?  Highdesertranger

Rigid.

 

[wayne49]

@PlethoraOfGuns

Which brand is that rivet nut tool?

Strange deal with rivet nut tools, any that are available "off the shelf" retail look to be Chinese.

There are US manufactured rivet nut tools, but with no prices listed, one has to request a quote from a distributor. Exception is McMaster-Carr, they have a tool @ $157.29.

 

[highdesertranger]

For rigid panels I would mount them on a rack. Are you planning on using the "Z" brackets? If you are they do not enough surface area to hold panel with tape only. Highdesertranger

 

[PlethoraOfGuns]

I have no idea what brand it is. Probably some Chinese variant of some sort unfortunately.

 

[Sofisintown]

For rigid panels I would mount them on a rack.  Are you planning on using the "Z" brackets?  If you are they do not enough surface area to hold panel with tape only.  Highdesertranger

Yeah, thank you, I was worried about that, and the roof is not even flat, so with modifications it will all get worse... I'll stick to the original plan to put them on the rack.

 

[Klupduck]

Thank you for all the options! @highdesertranger I have 4 Renogy rigid panels, I got similar mounts to the ones @Bobhdus linked. Do I use the YHB tape to secure the mounts and screw the panels in to the plastic, and will that be enough clearance? I do have an aluminum roof, to whomever asked, and the entire van is insulated and has a second layer of aluminum, a delicious sandwich. Walls and ceiling are around 2" thick. That rivnut tool is awesome, and even if I don't need it for this project, it is incredibly useful for other plans I have brewing. Thanks again!