Mounting Safely

[Jolly Roger bus 223]

not to complain.
if you have access to both sides and the tools then red loctite will keep it together until you need it apart.
have put that on many header bolts and regretted it later.

 

[Kentucky Dreaming]

I have a van with raised fiberglass roof. 3 - 100w flexible solar panels. Vhb tape on all 4 edges of each. All 4 edges sealed with eternabond. Parked outside year round in KY. After 18 months one came loose at 70mph on I-65 in Nashville. Did NOT come off but folded up and made a terrifying noise banging on the roof. Was able to immediately pull over and pull it off by hand. Pulled the other 2 off when we got home. No more VHB for me. Our bus build has Iron Ridge rails on each side thru bolted at every hat channel with 3/8 grade 8 bolts with flat washers nylock nuts. See Chuck Cassidy. Each slapped individually and blessed with "that ain't goin' nowhere".
You mileage may differ but VHB, rigid panels and a round roof are scary.

It's Cassady, but I agree with you as far as no tape or glue.

 

[Kentucky Dreaming]

I read what hubbard bus said about the VHB and eternabond. I am in 100% agreement. Ruth and I have tens of thousands of miles with 12 Panels on the roof of our 40' International. I can confirm that there will be times that the stress applied to your panels is going to be such that you don't want to find out if your mounts will hold.

You say that you have hat channel for the front mount, but not the rear mount of the panels. Consider something like 1"x1/8" square tube to build a rack that attaches to both sides of the bus and goes over it. As it has been mentioned, this subject has been thoroughly discussed on this forum, and a deep dive into the various threads will likely inspire more than one good solution to apply to your project.

When it comes to securing things to the outside of your bus, that could become deadly projectiles, therefore ruining all the fun, it is good sense to over engineer by a New Mexico mile. That's a :that ain't goin nowhere," times ten.

We are currently doing a build on an Eagle Coach. Not only have we secured our 14 panels with a rack and mount system, we ran a security cable down both sides, securing each panel to it's neighbors. Our racks are bolted to the roof with 1/2" rivnuts, but to be real sure we also used SikaFlex P2G between the racks and the roof, and the mount brackets and the panels.

If we ever have to replace a panel it will take an act of congress to get it removed.

Congress has quit acting.

 

[Kentucky Dreaming]

trust me red loctite will not back off without torch heat but blue you can get loose with with a breaker bar or heat gun heat.
i am sure one of the geniuses here can find a lock tite video.
mine is real experience.
i have been told that lock tite green is better but have never seen or used it

I have used Loctite Green. It is not a thread locker. It is for bonding dowel pins and other press or slip fit joints.

 

[Crlefley]

Not to thread jack, But I am in the process of deciding how to mount my panels as well. Im thinking of L brackets. Ive also considered some unistrut channel. Im conflicted whether I build a whole rack to go down the sides and bolt to the vertical portion of the hat channel. Makes it easier to build a square deck so to speak. I am thinking 6-8 panels. Ive also got another tricky trick up my sleeve.
But.. Whatever. Itll for sure be nuts and bolts.

 

[Mr P]

FWIW, I'm in the (slow motion) roof raise mode now. I chose to put 3/8" bolts up through the hat channels on preset intervals (using a jig). This way I have studs on the roof that can be used to anchor whatever bracket I want to use in the future. One less thing to have to think about right now....

 

[Crlefley]

FWIW, I'm in the (slow motion) roof raise mode now. I chose to put 3/8" bolts up through the hat channels on preset intervals (using a jig). This way I have studs on the roof that can be used to anchor whatever bracket I want to use in the future. One less thing to have to think about right now....

I was thinking of something similar. Especially the fact of pushing the stud up through the roof as opposed to the bolt head being on the outside. regardless of what I do it will be studs. Ill likely weld the bolt head to the channel on the inside. Its the only logical way to visually inspect the fastener loosening up on its own (the nut).
Seems to be the smarter way.

 

[Mr P]

I used a nut on mine, but since it's only pinching a couple layers of sheet metal, there's enough stud left for adequate bracketry and an additional nut. I thought about drilling though the end to use a cotter pin or safety wire later....but I wimped out.

 

[Rucker]

So you think that as long as there’s are two brackets screwed into the rib that tape for the other 2-4 brackets will be safe

Coming back to this thread because unfortunately I missed your question earlier.

My panels are about 36x50 inches. They have six panel brackets, three per side. The panels are bolted to the panel brackets with (I think) nylon locknuts and (for sure) loctite.

Each panel bracket is secured to the fiberglass roof with VHB and three stainless steel screws with the proper pilot hole drilled in the fiberglass (I took a section of fiberglass and experimented to get the right hole size for perfect screw bite). The brackets are covered with Eternabond where they lay flat on the roof (because VHB is not UV-resistant).

I check the panels every season, and perhaps once every other trip or two. After four or five years, they have not changed or loosened in any way. I'm quite confident they are going to last the life of the bus.

 

[Crlefley]

@Rucker I am fortunate that my roof is steel. But I think ill be going the route of @Mr P and poking studs through to check my nylock nuts on the top side. now to decide if I mount vertical posts off the sides and build off that, or do brackets on the top of the roof..... hmmmmm.

 

[Mr. Beefy]

My hard-drive recently took a dump, so I don't have any pics at the moment, but we did the 'studs up through the ceiling' thing, along with superstrut/unistrut. It's kind of hard to describe w/o pics, but I'll be up there finishing up the solar install in the next couple weeks, so I'll chime in here while doing so. The summary is this: While 1-5/8" superstrut works, it's bulk/strength ratiio leaves something to be desired... it's unnecessarily 'large' compared to suitable alternatives. The main advantage to me is that if you live in a dry-enough climate, the galvanized coating (silver or gold) seems to hold up really well, but of course that doesn't apply to any cuts you make, which are then kind of hard to color-match with paint to protect such cuts if you care about things like that. If you want to paint the whole thing, however, that benefit becomes a liability, as getting paint to adhere well to galvanized steel is a PITA process.

It is nice to have the option to use strut-nuts to attach various items, but I can't say I trust them 100%, so anything that could potentially fly off will be secured in at least a few places with bolt/nut combinations that don't just rely on clamping force like the strut nuts do.

Had I been able to weld at the time I would have gone a different route. Nothing wrong with strut - I'm very confident it's going to be overkill for the job I'm tasking it with - but had I the skills & equipment at the time, I would have gone with aluminum tubing first, or steel tubing with a well-adhered finish second.

 

[Crlefley]

My hard-drive recently took a dump, so I don't have any pics at the moment, but we did the 'studs up through the ceiling' thing, along with superstrut/unistrut. It's kind of hard to describe w/o pics, but I'll be up there finishing up the solar install in the next couple weeks, so I'll chime in here while doing so. The summary is this: While 1-5/8" superstrut works, it's bulk/strength ratiio leaves something to be desired... it's unnecessarily 'large' compared to suitable alternatives. The main advantage to me is that if you live in a dry-enough climate, the galvanized coating (silver or gold) seems to hold up really well, but of course that doesn't apply to any cuts you make, which are then kind of hard to color-match with paint to protect such cuts if you care about things like that. If you want to paint the whole thing, however, that benefit becomes a liability, as getting paint to adhere well to galvanized steel is a PITA process.

It is nice to have the option to use strut-nuts to attach various items, but I can't say I trust them 100%, so anything that could potentially fly off will be secured in at least a few places with bolt/nut combinations that don't just rely on clamping force like the strut nuts do.

Had I been able to weld at the time I would have gone a different route. Nothing wrong with strut - I'm very confident it's going to be overkill for the job I'm tasking it with - but had I the skills & equipment at the time, I would have gone with aluminum tubing first, or steel tubing with a well-adhered finish second.

This is great info. Ive toyed around with the strut option, but believe ill be better suited with some 1" or 1.5" square stock to weld/nut/bolt whatever I want however I want. I do also like the idea of unistrut track, but it leaves the points you made to be debated. The fasteners for them are very versatile, especially when it comes to mounting the panels. I think I may end up doing a combination of both. A solid square tube frame, with unistrut for my panel mounts, and the rest framed up for my accessory things.

 

[Mr P]

Oh, to clarify, I put a 3/8" grade 5, I think 1" thread length up through the hat channel and tightened it with a home made lock nut on top. To make a lock nut, take a normal nut and only thread it about 1 turn onto a bolt, when smash it with a hammer on the open end. Practice makes perfect.

 

[Crlefley]

Oh, to clarify, I put a 3/8" grade 5, I think 1" thread length up through the hat channel and tightened it with a home made lock nut on top. To make a lock nut, take a normal nut and only thread it about 1 turn onto a bolt, when smash it with a hammer on the open end. Practice makes perfect.

I have done the hammer method many times friend. Works like a charm.

 

[Conversion Noob]

Currently have a 200W on my RV and after visibly seeing the difference in charging compared to a smaller solar panel which the owner was able to move and aim in direction of the sun I've decide to not have my next solar panels laid down flat across the roof simply because they're not efficient when the sun is less prevalent during winter months.

Been living in my RV since Sept 2019 so I've had lots of opportunity to experiment with solar charging and having the ability to angle the panels is crucial during winter months if not then adding more panels is the only way to get the same charge. So in order to save money, time, effort and most likely headaches it makes more sense to have less panels and smaller panels which I can direct towards the sun.

The other big benefit is that sometimes the RV lot I was parked at for the weekend only provided sun in the morning and/or late afternoon for a few hours so again I'm left with batteries only partially charged however if I were able to angle the panels they would have easily fully charged the batteries in that limited time.

something to think about IMO

 

[Mr. Beefy]

Currently have a 200W on my RV and after visibly seeing the difference in charging compared to a smaller solar panel which the owner was able to move and aim in direction of the sun I've decide to not have my next solar panels laid down flat across the roof simply because they're not efficient when the sun is less prevalent during winter months.

Been living in my RV since Sept 2019 so I've had lots of opportunity to experiment with solar charging and having the ability to angle the panels is crucial during winter months if not then adding more panels is the only way to get the same charge. So in order to save money, time, effort and most likely headaches it makes more sense to have less panels and smaller panels which I can direct towards the sun.

The other big benefit is that sometimes the RV lot I was parked at for the weekend only provided sun in the morning and/or late afternoon for a few hours so again I'm left with batteries only partially charged however if I were able to angle the panels they would have easily fully charged the batteries in that limited time.

something to think about IMO

Very well put. I don't think most people realize how much power they're throwing away in the winter with flat-mounted panels on the roof. That said, that's exactly what we're doing in the next couple weeks, as there are just too many battles to be fought right now, but in the future I plan to improve along the lines you suggest. I also hope to supplement with a portable array, which would allow us to locate some panels in the sunshine (as well as angle them appropriately) while allowing the bus the option of remaining in the shade somewhere nearby, but I haven't figured out the logistics of where/how the panels would be stored, how they'd be deployed, etc.

 

[nikitis]

You can still do flat mounted panels and will likely get better charging "IF" both sides of the bus are in their own string of series. If they are all together, then one panel getting shade will take down all of them, the more you break them up in Parallel the better the charge rate in shady conditions (Or winter). You require slightly higher wiring AWG in some areas this way, as the amps increase, but your voltage drops lower. If you are like out in Arizona all the time where it's sunny, more in Series is gonna be better for it.

So it's not necessarily just about having them flat or angled, it's also how you wired the array.

If given the same configuration wired wise where they are more in parallel to isolate the banks more to fight shade, having them all at the same angle is gonna work out only slightly better. But looks worse, so it's kind of a preference thing.

If you are suffering from low charge rates, consider re-wiring to where more panels are in parallel and you'll get a better charge rate, but you also need to recalculate the MPPT controller to ensure it can handle it. Most of the times it can but not always.

 

[Conversion Noob]

It's the wiring that's the issue, it's the lack of "12 o'clock sun"/perfect angling. When you're able to move the panels as the sun moves or as I'd mention in a scenario where it only shines through at the end of the day for a few hours having the ability to have the panel face directly into the Sun is where panel mobility Rocks!

I've seen what my 200W solar panel was producing versus my friend's 75Watt panel and because he was able to have his panel always facing the sun he produced a lot more than my fixated set up.

 

[Iceni John]

I have 2kW of tiltable panels hinged to a central walkway, with four panels each side. The walkway runs between the two roof hatches, and is through-bolted to the roof ribs every 19" with 3/8" stainless bolts and nylok nuts, with cross-bracing to eliminate any potential sideways or longitudinal movement. Each panel sits inside a separate support frame to lessen the stress on the panel's own frame, and each support frame is hinged to the walkway with multiple 1/4" SS bolts and nylok nuts. The outer edge of each panel is located onto a continuous 25' length of 6061 angle that's through- bolted to each roof rib with 5/16" SS bolts and nylok nuts. I would consider this as the absolute minimum of security and attachment strength; I've joked when saying my bus could be lifted by its panels, but that's not far off the truth.

For everyone else's sake do NOT glue PV panels to the roof of a vehicle that can experience wind speeds as high as a hurricane's. How would you explain to a judge and jury why you thought that sticky tape was better than any other method? Please get real. If you can't be bothered to do it right, don't do it at all.

John

 

[jayb-SKO]

I have 4 300 watt solar panels mounted on my roof (bus) divided into two sets and connected to Victron charge controllers. The panels are mounted flat but I intend to change that. I have a third charge controller that is connected to a 48 volt charger, connected to shore power when available. I have 600 amps of battery storage as well as a switch to charge the bus batteries.