Solar rail/aluminum angle help

[neuronmisfires]

Hi all!

We have a ton of 1 1/2” aluminum angle and we’d like to use it as solar rail.

Two major questions:
1) How should we bolt/nut aluminum angle to aluminum angle without any nasty chemical reactions? Stainless steel bolts?

2) What kind of bolts should we use to attach aluminum directly to the roof? We were thinking quarter twenty bolts through the the roof and studs w nylock nuts below.

We’re thinking of doing something like this photo. Cue look at this photograph song.

Thanks!

Sam & Jasmine
Www.instagram.com/bedbusandbeyond

 

[Doktari]

Hi. I love aluminum. Got any extra. I’ll be over in 5 minutes lol. You will get a different opinion from just about everyone lol? Personally I would use larger than 1/4” SS (stainless steel) bolts to the roof. I’ve been told several times not to overtighten SS as it can twist right off. So biggerbolts makes sense to me. It depends how many there are. Fewer but bigger bolts is less drilling and sealing.
It’s a consideration to have air flow under the panels as the output voltage drops as they get hotter. So I put my panels up on the expedition rack on my van. But now they occupy half my expedition rack and can get caught on branches, etc.
We use ordinary stainless bolts for mounting the panels to aluminum or galvalume unistrut but I’m not sure what grade of stainless they are. Perhaps someone more knowledgeable about metallurgy can answer that.

 

[o1marc]

Hi. I love aluminum. Got any extra. I’ll be over in 5 minutes lol. You will get a different opinion from just about everyone lol? Personally I would use larger than 1/4” SS (stainless steel) bolts to the roof. I’ve been told several times not to overtighten SS as it can twist right off. So biggerbolts makes sense to me. It depends how many there are. Fewer but bigger bolts is less drilling and sealing.
It’s a consideration to have air flow under the panels as the output voltage drops as they get hotter. So I put my panels up on the expedition rack on my van. But now they occupy half my expedition rack and can get caught on branches, etc.
We use ordinary stainless bolts for mounting the panels to aluminum or galvalume unistrut but I’m not sure what grade of stainless they are. Perhaps someone more knowledgeable about metallurgy can answer that.

Stainless can be brittle and break under heavy load. Use a grade "8" bolt. 1/4" x 20, grade "8' has a clamp load of over 3k lbs and 5500lbs of shear strength. I doubt you'll ever see loads on the panels near those numbers. I'm using a rivnut/threaded insert in the roof into the center of a rib. Sikiflex on the threads will seal them.
One problem with bolting the frame together is bolt head or nut causes clearance issues with the panel sitting correctly in the channel. A couple of thin head rivets in each corner should work, ultimately you would want to weld those corners for strength.

 

[neuronmisfires]

Ahh thanks for the info! We were leaning toward stainless but grade 8 sounds pretty solid. I suppose we’ll see how much pricier those are than stainless! I certainly don’t want these things flying off at highway speeds ��

Here’s the proposed angle configuration on our roof! I wanna put two frames on both of the curved sides of the bus (we have the curved z bracket renogy feet) but that leaves our panels at a less than optimal angle, which seems bad. I guess I could use some blocking or something to raise the lower sides of the rail? Maybe I’ll take a better picture and put up a new thread up in a bit about that.

 

[neuronmisfires]

http://imgur.com/gallery/htjTc5H

 

[o1marc]

Ahh thanks for the info! We were leaning toward stainless but grade 8 sounds pretty solid. I suppose we’ll see how much pricier those are than stainless! I certainly don’t want these things flying off at highway speeds ��

Here’s the proposed angle configuration on our roof! I wanna put two frames on both of the curved sides of the bus (we have the curved z bracket renogy feet) but that leaves our panels at a less than optimal angle, which seems bad. I guess I could use some blocking or something to raise the lower sides of the rail? Maybe I’ll take a better picture and put up a new thread up in a bit about that.

Find a different way to post pics, those little blue squares don't show anything.
Is there a universal optimal angle when at rest? Optimal would be able to adjust the angle dependent on location and time of year.

 

[neuronmisfires]

Ah crap good to know!