Cheap/odd way to mount panels on cargo trailer

[jamiko]

I'm looking for a simple, cheap way to mount solar panels to the roof of a 6x12 cargo trailer. I am trying to avoid putting holes in the one piece roof. I ran across an older video where someone used a post brace bracket and 2x6's to mount the panels. I was also thinking about running the two wires through the top side vent. Thoughts? Good idea? Bad idea?

 

[12VoltInstalls]

Having worked at a utility trailer dealer for almost a year once and many dozens of fabrication projects and installations over the years from boats to RVs I feel like I can speak with some credibility on this.

Contractor roof racks on box trailers are installed often with ‘feet’ on the edges of the top surface and the verticals bolted through the sides. Depending on the manufacturer or fabricator these are often through-bolted from the top through dicor or polyurethane sealant. This keeps any weight off the more flexible portions of the roof and minimizes perforations in the roof.

A similar arrangement would be beneficial to attach rails to for solar panels. Not cheap but not expensive, either.
Attachments depict a design that’s not too bad- there’s plenty of bad designs. [I’ve had to install a few ]
Amazon has ‘adjustable’ pairs in a much poorer design for $200 - or on up to over a grand- that could be the quickest procurement and low buck for what it is

 

[jamiko]

I have looked into roof racks. They were my first thought and I am still considering them. Many would have the panels a foot or more higher then the roof. I'd prefer just a couple of inches to keep the height clearance lower. Many have longer vertical shafts extending up which I think my shade the panels too often. Shade will cause power loss. One thing I had not considered is simply cutting them to fit more to my liking.

 

[Short_Shot]

I have looked into roof racks. They were my first thought and I am still considering them. Many would have the panels a foot or more higher then the roof. I'd prefer just a couple of inches to keep the height clearance lower. Many have longer vertical shafts extending up which I think my shade the panels too often. Shade will cause power loss. One thing I had not considered is simply cutting them to fit more to my liking.

Look at how the roof rack is mounted and replicate that attachment method.

 

[12VoltInstalls]

how the roof rack is mounted and replicate that attachment method.

Exactly. Thank you- What I was trying to convey. I should have been more clear.

Many would have the panels a foot or more higher then the roof. I'd prefer just a couple of inches to keep the height clearance lower. Many have longer vertical shafts extending up which I think my shade the panels too often. Shade will cause power loss. One thing I had not considered is simply cutting them to fit more to my liking.

…and was what I meant by poorly designed.
A small local TiG shop may be able to make something precisely what you need for the same or even less than the manufactured items. The manufactured ‘part numbers’ products aren’t exactly things of beauty either, so you could actually wind up with something attractive

 

[McCarthy]

I'm looking for a simple, cheap way to mount solar panels to the roof of a 6x12 cargo trailer. I am trying to avoid putting holes in the one piece roof. I ran across an older video where someone used a post brace bracket and 2x6's to mount the panels. I was also thinking about running the two wires through the top side vent. Thoughts? Good idea? Bad idea?

Why do people try to cheap out on racks? Wood on a roof? Walking on your trucks hood and roof because they can't find a ladder?

Get some strut channel and do it right.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[Micky]

Depends on how constrained your budget is and what tools you have access to but if you're limited in funds and you don't want to drill holes anyway, there are various manufacturer's adhesives that will work. I'm most familiar with the Sikaflex range used in the marine industry but Bostik make a number of adhesives for structural applications as well. Sikaflex 291, (or 250-x though I think that's only sold directly to OEM's) should allow you to bond Al angle or even wood, directly to the roof. Set the upright inside the frame of the panel and you'll have a very neat and unobtrusive mounting system. For a 4"x6" Al flat on a properly prepped surface, 291 will give you a very strong bond. Look it up, but if I remember correctly 291 has something like 250 lbs/sq inch of tensile strength. You do the math for the surface area and the number of brackets used, but with six brackets I suspect you'd tear the roof off the trailer along with the panels if you or someone else got medieval on them. It's also flexible and resistant to vibration.

(Understand that this is neither instruction nor a recommendation for what you should do. It is a description of a method, that after proper testing, may be determined to be suitable for your particular application. If you decide to try this, you will of course do a number of test panels following the adhesive manufacturers recommendations. After proper surface prep, installation and complete cure, test them to failure using a calibrated and certified strain gauge. Post the results here along with full methodological and statistical analysis to get group approval. Which you won't get anyway since it's 'only' glue. Then decide how you choose to proceed).

Modern adhesives seem to get negative responses on this site from a number of people, so perhaps it's better that they don't seem to know that commercial jets and other vehicles, including many parts of the newer cars we drive, are glued together these days. Not afraid to fly or drive? Maybe you should be...

 

[Short_Shot]

Why do people try to cheap out on racks? Wood on a roof? Walking on your trucks hood and roof because they can't find a ladder?

Get some strut channel and do it right.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Idk if I'd call strut channel "right".

Adjustability and easy connectors are great, but...

Personally I'd get a couple pieces of 8020 to use as the crossmembers. Bolting aluminum aluminum = much good.

Bolting aluminum to steel = much less good and rust streaks everywhere later.

Bolting aluminum to stainless steel = much bad.

Regarding adhesives:

I love em. But I also love being able to remove things without needing to cut it free.

 

[12VoltInstalls]

Modern adhesives seem to get negative responses on this site from a number of people, so perhaps it's better that they don't seem to know that commercial jets and other vehicles, including many parts of the newer cars we drive, are glued together

I read the rest of your post, too. Certain amount of myopia and assumptions

I love “modern” adhesives (which basically were developed in the 50s-70s and merely developed on- so not so modern imho) and I’ve used polyurethane adhesives for years including below the waterline- so don’t assume that people “don’t seem to know”

Idk if I'd call strut channel "right".

Me either. People work in their subsets of knowledge or visible items and don’t always realize the scope of other options.

“Know enough to know what you don’t know”

 

[jamiko]

Depends on how constrained your budget is and what tools you have access to but if you're limited in funds and you don't want to drill holes anyway, there are various manufacturer's adhesives that will work.

I think adhesives are out due to the thin 0.030 aluminum panels on the cargo trailer. I don't think the thin aluminum panels will handle the weight of solar panels, but I could be wrong.

 

[jamiko]

Personally I'd get a couple pieces of 8020 to use as the crossmembers. Bolting aluminum aluminum = much good.

Bolting aluminum to steel = much less good and rust streaks everywhere later.

Bolting aluminum to stainless steel = much bad.

I was also thinking about some type of corner brace bolted to the side/top if the trailer. Then aluminum angle bolted to the corner braces and the panels bolted to the aluminum angle. The trailer is an all aluminum trailer.

 

[Short_Shot]

I was also thinking about some type of corner brace bolted to the side/top if the trailer. Then aluminum angle bolted to the corner braces and the panels bolted to the aluminum angle. The trailer is an all aluminum trailer.

I wouldn't really suggest that.

There are products for this application.

 

[McCarthy]

Idk if I'd call strut channel "right".

Adjustability and easy connectors are great, but...

Personally I'd get a couple pieces of 8020 to use as the crossmembers. Bolting aluminum aluminum = much good.

Bolting aluminum to steel = much less good and rust streaks everywhere later.

Bolting aluminum to stainless steel = much bad.

Regarding adhesives:

I love em. But I also love being able to remove things without needing to cut it free.

I only use aluminum strut channels, and they are MUCH cheaper than 80/20. Strut channels are also easier to attach to Rivnuts.