Renogy Z bracket question

[Tickled]

I should have been more specific in speaking about the use of alcohol & water and the Adhesion promoter when cleaning and preparing the surface.. I am only referring to the VHB tape when using these products NOT the sika sealant. My bad

[marter]

So I'm not sure what we're talking about here. Seems like two different things; clean and prep for 3m VHB tape, and then concern about using alcohol solvents on the Sikaflex?

First, cleaning and prepping the surface for the 3m VHB tape. It's clear that 3m recommends a 50/50 Isopropyl alcohol water mix. Mix your own or buy theirs. It dries in seconds.

Once the Isopropyl alcohol dries and the tape is applied, what's the concern about having used that solution in terms of the Sikaflex? The quote talked about tooling and the use of soapy water. Ok, but what does that have to do with what's used to clean the surface for the 3m tape?

Am I missing something here?

Thanks,
Mike

[thiel]

Originally Posted by marter

Well I guess this proves to each his own. The AMsolar brackets seemed expensive for what they are. Probably really well made but pricey.



Thiel, did you use 3m tape and Sikaflex? I am a little concerned about the curved brackets having enough surface area for the tape to adhere properly. Did you use carb cleaner or something else?



Thanks for the feedback.



Mike

Yup: VHB and sikaflex. Have about 3500 miles on them and they are rock solid.

I used isopropyl alcohol to prep the surface of the trailer.

[aswell]

Originally Posted by rmkrum

Philistine that I am, I plan to use the curved brackets. Since I am a ham radio operator, and need to have all the metal on the roof grounded and bonded, I’m going to drill holes and use rivnuts and SS screws to tie it all together. A bit of sealant under the mounts and screws will keep water out.

Has to be done to avoid RF burns and electronic damage from the transmitting antennas on the roof.
Deep apologies to Lewster, who will no doubt be appalled at this heresy...

Very good idea with the rivnuts, good to know. Preparing to apply Bus-Kote to the roof, was wondering how to mount solar brackets later...

[rmkrum]

I’d try spot removal of the Bus-Kote paint so the rivnut seats tight, then seal up. The foot should cover the removed paint areas.
I plan to use stainless steel 1/4-20 rivnuts and dome head screws that use a hex key to install. Plenty of sealant under the foot and on the screws as I run them in by hand.

[pteck]

Not a great shot, but here's how my panels are mounted. The brackets are only used as standoffs on one side where the roof skin slopes away. Using VHB to mount under brackets, and solar frame directly on other long end. Sealing edges with sikaflex.

This is the closet thing to curved panels in terms of being low profile. It's also likely the sturdiest way to mount them.

[SabaRocks]

Thank you all for the replies. After considering it all, I went with the curved brackets. I doubled up on them for good measure (i.e. overkill) and mounted with VHB tape and Sikaflex. Seems pretty darn sturdy... I would have had to bend the straight brackets to get them to work. Here are some pics for future reference.

[HaulinOats]

Can anyone see a downside to flush mounting your panels on one side like this?

Originally Posted by pteck

Not a great shot, but here's how my panels are mounted. The brackets are only used as standoffs on one side where the roof skin slopes away. Using VHB to mount under brackets, and solar frame directly on other long end. Sealing edges with sikaflex.

This is the closet thing to curved panels in terms of being low profile. It's also likely the sturdiest way to mount them.

Attachment 322850

[rowiebowie]

Originally Posted by HaulinOats

Can anyone see a downside to flush mounting your panels on one side like this?

You should contact pteck by PM. I'm sure he will give you an update on how his panel mount is working.

[GMFL]

Originally Posted by HaulinOats

Can anyone see a downside to flush mounting your panels on one side like this?

Yes,
#1 Heat build up. Panels become less efficient at higher temps. Allowing airflow helps keep panel a few degrees cooler. Also panels get hot( they are a dark color) and mounting that close to the roof will cause more radiant heat from the back of the panel to become “trapped” and heat up the roof skin under the panel.
#2 Debris build up. With panels mounted flush to the roof on one side leaves and other dirt and debris with build up and be very hard to clean out.
#3 Service. With panels mounted, frame to roof, you can’t easily remove on for service (i.e. diode check, wire connection maintenance, roof insection and service under panel, panel replacement.....)

Bracket make it easy to install and remove panels for repair, service, and any other reason you might have to remove them.

That’s just my thoughts. Pteck can give you the real world view.

[pteck]

My setup is still working and running great.

I would generally agree with most everything GMFL posted. As with everything, there's pros and cons. Given the trades, I would still mount my panels as I have, today.

Justification:
1) Low profile mounting to increase stability and decrease drag. I tend to drive faster than most and this is my trade to making sure the panels are secure, with least amount of impact to aero drag on the road. With the way the panels are right at the leading edge of the Airstream, air coming up and over the curved part will be channeled right into the panel. If it were mounted on standoffs, significant air buffeting and lift would be acting on the underside of the panels. Which gets translated to the 4 little brackets that are bonded to the thin aluminum sheet metal. As an aircraft engineer, I don't like later configuration.

2) Using standoffs only on the falling edge of the roofline helps mount the panel as flat as possible. This is an optimization to decrease the likelihood of very poor solar alignment when I'm parked with a panel sloping towards north. In RV solar, it's not so much about capturing as much production as possible during sunny days, in so much as it's about minimizing solar production loss on bad, gloomy, winter days. Because those are the challenging days that may actually require one to resort to a backup generator.

3) GMFL is right about heat but it would be very incremental. Again, if it's actually hot and sunny, there's plenty of solar production to go around and I'm never in a shortfall for power. It's about optimizing for off-nominal days, where my trade for flat mounting again has advantages to minimizing impacts.

4) Rigid solar panels are reliable these days and meant for 10-25 year lifecycle. I've had solar on my house for over 9 years now. No problems. I expect generally the same from RV solar installations. If I have to service it, sure, it doesn't just unscrew out. Just like many other maintenance items on the roofline that use adhesives rather than screws.

[rodsterinfl]

Greetings!

I know this is an older thread. I mounted my renogy panel, a monster 39x39, on the roof 8 years ago. One of my mounts failed. I need to redo. I have both the renogy z mount and the curved mounts spoken of in the thread. My question: Is the small contact point of the mount enough between taped point and trailer roof? The bracket is obviously designed for a screw mounting. I just wonder about the narrow contact point. That is where my one mount using the renogy Z mount failed.

[dznf0g]

Originally Posted by rodsterinfl

Greetings!



I know this is an older thread. I mounted my renogy panel, a monster 39x39, on the roof 8 years ago. One of my mounts failed. I need to redo. I have both the renogy z mount and the curved mounts spoken of in the thread. My question: Is the small contact point of the mount enough between taped point and trailer roof? The bracket is obviously designed for a screw mounting. I just wonder about the narrow contact point. That is where my one mount using the renogy Z mount failed.

I know there are those, including Lewster, who still maintain that the tape alone is enough. I've had my panels installed for over 5 years. Just a few weeks ago, I noted it was time for new sealer over the feet. Once the polyurethane was removed I noted the foam of the tape seemed crunchy and crackley, although the adhesive seemed in tact. I didn't like where this might be going, so I installed rivets in all the feet and re-sealed the feet.

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