Broken Panel Brackets

mspenc45

New Member
Joined
Sep 24, 2019
Messages
29
Has anyone witnessed cracked or broken aluminum panel mounting brackets on roof top mobile applications? I read of this in another forum, and just had a friend tell me that he had some friends visiting him in there Sprinter van when they noticed that every bracket on their solar panels was broken at the 90 degree bend. It was a miracle that the panels stayed on the roof. I am concerned as I am about to mount four 210W New Powa panels on our Super-C using VHV tape using these brackets. Perhaps using a bracket on the short ends of the panels as well would help reduce the swaying sort of movement I could imagine occurring if brackets are only used along the long edge of the panels? I don't have room for the plastic type brackets that also include corner brackets.
 

Boondock Saint

Solar Addict
Joined
Apr 8, 2021
Messages
652
I don't always use aluminum brackets, but when I do - I use twice as many.
 

Attachments

  • index.jpg
    index.jpg
    8.4 KB · Views: 1

mspenc45

New Member
Joined
Sep 24, 2019
Messages
29
I don't always use aluminum brackets, but when I do - I use twice as many.
I love it! I thought about SS, but didn't look for any since I've already purchased all aluminum. I know from my aviation experience that aluminum fatigues much faster than steel products. I am planning on using 4 each along the long edges and possibly add 1 more each along the short edge to prevent side to side oscillation.
 

Boondock Saint

Solar Addict
Joined
Apr 8, 2021
Messages
652
If you were to need to buy any more for that extra support, might be a grand idea to still get the SS versions?
 

jwelter99

Solar Addict
Joined
Dec 6, 2020
Messages
561
Go stainless. Good aluminum brackets I'd have no concern with but brackets that you get 16 for $20 from China you need to question the material quality.

And consider using screws or rivnuts to fasten them versus VHB. VHB works great until it doesn't, and it typically fails suddenly.

If a panel comes off on the highway and causes an accident, injury, or death you can be held liable. Do not expect insurance to cover a DIY installed solar panel not properly fastened.
 

Diysolar123

Photon Sorcerer
Joined
Feb 28, 2021
Messages
677
welcome to "china metals"...well, I am guessing but I suspect thats it.

Aircraft aluminum angle brackets are almost as strong as steel; the panel would fail long before the brackets give out or failed from fatigue (unless your RV routinely travels at over 200mph).

another of my favorites which I read about on this forum is that in the some areas (cough cough china) some vendors sell items by using "innovative" measurements such as copper cable, and it is actual copper...but for sizing they INCLUDE the diameter of the insulation when they mark the cables. SO an 8AWG cable does not have 8awg diameter of copper cable..but 8awg diameter of the insulation+a bit of copper wire hehe

It is imaginative you have to admit; clearly they all have advance degrees in "marketing".

so aluminum is probably "mostly" (as in 51%) cast aluminum with enough impurities to make a laptop hehe
 

jwelter99

Solar Addict
Joined
Dec 6, 2020
Messages
561
In many cases it's not even aluminum alloy but what we used to call "pot metal" which was low grade crap. They then bead blast it so it looks "nice" and uniform.

Look at the bends under a magnifying glass and if your can see little stress cracks you know it is a poor grade alloy not meant to be bent with a tight radius. They don't care. You solar panel coming off is not their concern.

Chinese stainless is not much better, but at least when bent with a tight radius it is typically not at prone to cracking as their cheap aluminum. So you might get some better life out of them.

It is too bad Temco who makes a very nice tall Z bracket doesn't make a short version.....
 
D

Deleted member 23531

Guest
Please share a picture of your mounting frame. I recently used a ton of 80/20 for a non-mobile install and it was super clean and convenient. Perhaps you could just drill holes in your mounting frame as needed instead of using brackets. In my opinion using brackets is a sign of a "generic" install using off-the-shelf parts, which you could improve upon if you do more labor for a custom install, justing using a drill and some thinking. Obviously this depends on the specifics of your installation.
 

mspenc45

New Member
Joined
Sep 24, 2019
Messages
29
Please share a picture of your mounting frame. I recently used a ton of 80/20 for a non-mobile install and it was super clean and convenient. Perhaps you could just drill holes in your mounting frame as needed instead of using brackets. In my opinion using brackets is a sign of a "generic" install using off-the-shelf parts, which you could improve upon if you do more labor for a custom install, justing using a drill and some thinking. Obviously this depends on the specifics of your installation.
I had thought about direct attaching my panels to the roof using VHB tape, but two issues restrict such, the first is that my RV roof is slightly ever so slightly arched. There's no arching that panel to fit it. The second and probably just as important is that there would be no air flow under the panel if it was not a directly. I am using the Newpowa 210 watt panels for my build.
 

Geokilroy

Solar Enthusiast
Joined
Aug 14, 2021
Messages
74
Location
Las Vegas, NV
I love it! I thought about SS, but didn't look for any since I've already purchased all aluminum. I know from my aviation experience that aluminum fatigues much faster than steel products. I am planning on using 4 each along the long edges and possibly add 1 more each along the short edge to prevent side to side oscillation.
Is there anyone selling SS brackets? I have to have mine custom because I want the mounting bolts to go thru the outside edge of the panel frame instead of up thru so I can check, tighten, or remove the panel without getting into the roof sealant. SS bolts w/lock inserts in the nuts. I am changing my mount set-up because one of my brackets pulled out of the roof. I am going with strut channel attached to roof and custom cross brackets to mount the panel. I'll start a new feed to show what I end up with. I have a construction background and am handy with tools and getting shops and people to custom what I want.
 

grizzzman

Some say "Why" and some say "Why not?"
Joined
Sep 21, 2019
Messages
1,258
I made mine out of T6 3/16" aluminum angle. The base piece 5" long with 4 staggered screws and polyurethane to seal and glue. then a 2" piece that attached to the panel. A single bolt ties the two parts together. This way the panel can be removed with out messing with the sealant. I would never suggest gluing down a panel. Two family members have lost panels using that method.
 

Browneye

Dr. WattSon
Joined
Nov 2, 2021
Messages
1,068
Location
Southern California
Let's see...here's how I did my calcs for panel mounting.
With 4 z-brackets 1.5" by 3" = 18 square inches for VHB tape at approx 18psi per 3M data sheet on their acrylic adhesive, so about 324lbs of strength. This is how they rate glazing for high-rise buildings with VHB.

I used strut channel, 1.5" x 60 x 2 for each panel = 180 square inches, or about 3,240lbs of strength.
Based on the wind loading engineering analysis elsewhere here in Wiki, a single 58x26: PV panel could achieve approximately 250lbs of lift on a roof with a 2 to 3" space underneath in 90mph winds. Or about 30mph headwind on a vehicle traveling 60mph.

I wanted about a ten-times margin of safety in holding strength for my panels - pretty sure I achieved that. I also added 3ea #14 self-tapping screws to each channel to ensure a good holding bond for the adhesive, even if they don't have much holding power in a thin fiberglass roof over luan plywood. And finally, all edges sealed with sikaflex urethane sealant to keep any moisture out of the tape bond.

We've done about a thousand miles now, with headwinds up to 40-50mph - they're not going anywhere.

IMG_4077.HEIC
 

toms

Photon Sorcerer
Joined
Jul 24, 2020
Messages
962
Where i come from, these plastic kits are the most popular way to mount panels.

Mostly just glued on.

If you fill in the gap between the front mounts with another sheet of plastic it stops wind (when travelling) getting under the panel.
 

Attachments

  • B3E02C64-AEBE-46FC-B1C6-FB419CEB8A1B.jpeg
    B3E02C64-AEBE-46FC-B1C6-FB419CEB8A1B.jpeg
    155.5 KB · Views: 3

HRTKD

Boondocker
Joined
Apr 24, 2020
Messages
7,467
Location
Somewhere South of Denver
Where i come from, these plastic kits are the most popular way to mount panels.

Mostly just glued on.

If you fill in the gap between the front mounts with another sheet of plastic it stops wind (when travelling) getting under the panel.

Those mounts should not be used on EPDM roofs, unless you also screw down the mounts.
 

Rocketman

Solar Addict
Joined
Sep 27, 2020
Messages
698
What roof material does the OP have on his class c? Probably not fiberglass… VHB works great on fiberglass roofs.

I made my own brackets too. Cut some 1-1/2 alum angle into 6” pieces. Bolted one piece to the bottom of the panels w/ 10-24 SS bolts and lock nuts. Attached other piece to fiberglass roof. VHB + Dicor + a screw. And bolted together w/locknuts (1/4”). I like my design because I can remove the panels from the roof, or tilt them (if I ever make tilt bars). Helps with maintaining the roof and stuff on the roof. I made mine in a C shape, when we did my father’s roof - he did his in a Z shape. On his TPO roof 2 or 3 screws per bracket covered completely with dicor.
 

HRTKD

Boondocker
Joined
Apr 24, 2020
Messages
7,467
Location
Somewhere South of Denver
What roof material does the OP have on his class c? Probably not fiberglass… VHB works great on fiberglass roofs.

I made my own brackets too. Cut some 1-1/2 alum angle into 6” pieces. Bolted one piece to the bottom of the panels w/ 10-24 SS bolts and lock nuts. Attached other piece to fiberglass roof. VHB + Dicor + a screw. And bolted together w/locknuts (1/4”). I like my design because I can remove the panels from the roof, or tilt them (if I ever make tilt bars). Helps with maintaining the roof and stuff on the roof. I made mine in a C shape, when we did my father’s roof - he did his in a Z shape. On his TPO roof 2 or 3 screws per bracket covered completely with dicor.

A custom bracket that allows the panel to be removed would be awesome. I wish I had thought of that before I installed the Z brackets. :(
 

Hedges

I See Electromagnetic Fields!
Joined
Mar 28, 2020
Messages
10,602
Aircraft aluminum angle brackets are almost as strong as steel; the panel would fail long before the brackets give out or failed from fatigue (unless your RV routinely travels at over 200mph).

Aircraft aluminum ain't what it used to be.

An associate has the job of testing aerospace systems in various vibration and shock conditions (think of a voice coil the size of a washing machine for vibration testing of an electronic assembly.) For shock, an X shaped block was machined from aluminum and stretched until it broke. He said in the old days, they broke with consistent force in a narrow band above spec. More recently, much wider range of breaking strength, and often below spec.

I don't always build aircraft with aluminum brackets, but when I do - I think I'll use twice as many.
 

Browneye

Dr. WattSon
Joined
Nov 2, 2021
Messages
1,068
Location
Southern California
The strut channel nuts allow my cross supports to be easily removed for servicing or replacement. Or even converted to a tilt-mount if desired. I thought about it for a time, then decided I'm too lazy to climb up there to futz with them, so they're flat. Tilting, especially during winter/low sun, can make a pretty big difference in solar gain - I saw 30% when messing with my portable ones.

I could have used aluminum angle for the cross pieces easily...for $20 and convenience I just got another 10' piece of strut channel.

Blocking the front might block a little bit of air from getting under, but keeping them low serves pretty much the same purpose. I thought the air dams in front were cumbersome at best. I saw someone use eternabond tape to make them, but then you would have all that sticky on the back. Didn't appeal to my senses for a lot of reasons.

The plastic corners are okay, but they are not all flat on the bottom - just a 1" or so area that contacts the roof surface. They didn't appeal so much to me either, I didn't like the way they look, and wasn't all that excited about the plastic material.

With the 13/16 tall channels, they are really pretty low profile.

IMG_4078.HEIC


IMG_4114.HEIC
 

Geokilroy

Solar Enthusiast
Joined
Aug 14, 2021
Messages
74
Location
Las Vegas, NV
The strut channel nuts allow my cross supports to be easily removed for servicing or replacement. Or even converted to a tilt-mount if desired. I thought about it for a time, then decided I'm too lazy to climb up there to futz with them, so they're flat. Tilting, especially during winter/low sun, can make a pretty big difference in solar gain - I saw 30% when messing with my portable ones.

I could have used aluminum angle for the cross pieces easily...for $20 and convenience I just got another 10' piece of strut channel.

Blocking the front might block a little bit of air from getting under, but keeping them low serves pretty much the same purpose. I thought the air dams in front were cumbersome at best. I saw someone use eternabond tape to make them, but then you would have all that sticky on the back. Didn't appeal to my senses for a lot of reasons.

The plastic corners are okay, but they are not all flat on the bottom - just a 1" or so area that contacts the roof surface. They didn't appeal so much to me either, I didn't like the way they look, and wasn't all that excited about the plastic material.

With the 13/16 tall channels, they are really pretty low profile.

IMG_4078.HEIC


IMG_4114.HEIC
Thats just what I planned. I would widen the space between the channel mounted to the roof to allow upgrade to wider panel. Mabe I will use an aluminum tube, either square or 1 x 2 1/2" rectangle for the cross pieces. If I think it needs more support-just add another cross piece. Will still be able to service it without messing with the roof sealer. And it will be easier to upgrade to a larger panel by only changing the cross pieces to fit wider panel.
 
Top