Building a solar panel support structure with wood/fiberglass /epoxy

[socalspearit]

Well, since you asked! As for using wood/fiber composites instead of aluminum bar, for Jezebel, I went with a composite structure and executed it to its most absurd conclusion.

For her rear radar/antenna tower which I wanted to be nicely curved, crazy light, strong and durable beyond my own lifetime (also functioning as a luggage rack), very low profile, and hollow for multiple cable runs, I did composite wood and carbon fiber. Her vertical sections are mostly 0.9" carbon fiber tubes (for cable runs) sandwiched inside white oak, with a woven CF sleeve vacuum processed around them. The primary horizontal members were made similarly, and her trusses are solid western red cedar or mahogany with a CF sleeve vacuum processed around them. The vertical tower pieces were notched with a router to accept the horizontal members, and then joints were mildly reinforced with thin glass. No screws were used to assemble the structure, just lapjoints, epoxy, glass and dowels. The radar mount on top is western red cedar and fiberglass, and hollow with an access hatch on the starboard side. There's also a few small flush access hatches at points where the thick radar cable has to make a 90 degree turn in the internal channel so it can be installed without needing to be cut.

I didn't weigh it but I'd estimate the total weight of the structure to be maybe 15lbs and thickest portions are 1"x1.5". I can do chin-ups off it with zero deflection but under G forces I wouldn't put my weight on it. Pushing sideways against the top corners it will deflect and spring back a little but in actual use it shouldn't regularly be subject to that kind of force vector. If it turns out I'm wrong on that and it bounces and wobbles I'll add diagonal braces. The tower is not bolted on but actually goes through the rear decking to the depth of the outwales and is permanently bonded to the hull with epoxy and through hull dowels.

The attached files are not final but to get the tower perfectly smooth, faired, etc--in addition to the build time--was countless hours.

 

[groper]

I’ve decided to go a different way and build a large solar hardtop from carbon fiber beams and glass solar panels.
The beams will be 150mm x 50mm rectangle sections , with PVC foam core .
Laminate will be 450gr dbias and 450gr unidirectional for most , however additional uni will be used on the vertical posts and main load bearing horizontal beams which support the longitudinal beams.
Aluminium framed glass solar panels will be edge bolted between longitudinal beams so the top surface is flush. Solid glass inserts will be provided inside the beams so the bolts can be tapped into the beam walls.

the beams will be laid up in these 2 half molds which are under construction. The foam core will be glued in, along with any inserts and cable conduits , then the 2 halves brought together with the 50mm edges overlapping as the bonding flanges .

If you’re gonna do something , do it once and do it right !

 

[BlueDogOz]

I’ve decided to go a different way and build a large solar hardtop from carbon fiber beams and glass solar panels.

If you’re gonna do something , do it once and do it right !

I agree and I am intensely interested in this , and your previous post on page 3 ... more when convenient please

 

[groper]

I agree and I am intensely interested in this , and your previous post on page 3 ... more when convenient please

Hi mate - I’ll be updating about all this on my build thread here ;

60ft eX race yacht to cruiser conversion. https://www.boatdesign.net/threads/60ft-ex-race-yacht-to-cruiser-conversion.68399/

 

[Michael11]

Hey guys I know most people use stainless steel or aluminum to build solar panel support structures but is there any reason you can't build it out of dimensional lumber like 2x4s or 4x4s sealed with biaxial fiberglass and epoxy resin? You would have to round out the corners to properly fiberglass it but are there any reasons why this would be a bad idea?

I figure as long as you properly seal it and use enough of the biaxial glass it would be strong enough and would last a long time but please correct me if I'm wrong!

Thanks for all the help and advice guys I really appreciate it!!!

Using dimensional lumber sealed with fiberglass and epoxy for solar panel supports could work, but it may not be as durable or strong as stainless steel or aluminum. Wood can degrade over time despite sealing, and it may require more maintenance. It could also be heavier and less stable in extreme weather. Metal is usually a more reliable choice for long-term durability and strength.

 

[groper]

Using dimensional lumber sealed with fiberglass and epoxy for solar panel supports could work, but it may not be as durable or strong as stainless steel or aluminum. Wood can degrade over time despite sealing, and it may require more maintenance. It could also be heavier and less stable in extreme weather. Metal is usually a more reliable choice for long-term durability and strength.

Pretty vague reply there - MAY not be as durable or strong , COULD be heavier , CAN degrade over time etc . Same applies to anything .
You CAN make it strong , CAN make it reliable etc however it’s GENERALLY not as easily accomplished using these materials as it is using other materials with a higher modulus (stiffness ) . This is because the structure usually requires thin element beams which are more efficiently designed and constructed with high modulus material such as metal or carbon, rather than low modulus / soft material like wood and fiberglass. It can be done , same as you can build a wooden or fiberglass mast, however it will be heavier for the same deflection performance.

 

[Michael11]

Pretty vague reply there - MAY not be as durable or strong , COULD be heavier , CAN degrade over time etc . Same applies to anything .
You CAN make it strong , CAN make it reliable etc however it’s GENERALLY not as easily accomplished using these materials as it is using other materials with a higher modulus (stiffness ) . This is because the structure usually requires thin element beams which are more efficiently designed and constructed with high modulus material such as metal or carbon, rather than low modulus / soft material like wood and fiberglass. It can be done , same as you can build a wooden or fiberglass mast, however it will be heavier for the same deflection performance.

You’re absolutely right—wood and fiberglass can be strong, but it’s harder to achieve the stiffness and efficiency of materials like metal or carbon. For solar panel supports, metal is usually better because it’s lighter and performs better for the same strength. It’s all about choosing the right material for the job!

 

[TeddyDiver]

You’re absolutely right—wood and fiberglass can be strong, but it’s harder to achieve the stiffness and efficiency of materials like metal or carbon. For solar panel supports, metal is usually better because it’s lighter and performs better for the same strength. It’s all about choosing the right material for the job!

Depends of several factors, usually (as you say) which isn't exactly true https://cdn.prod.website-files.com/...bc6a057dc9e037f5_1*roMpPdHWeLp0huNd_r-K0Q.png

 

[Will Gilmore]

efficiency of materials

Efficiency is more subjective than most engineers understand. If cost, familiarity, access, and DIY friendly are to be factored in, efficient construction may also mean glass over wood is superior to ss. Esthetics is also a big consideration for most.

-Will

 

[Michael11]

Depends of several factors, usually (as you say) which isn't exactly true https://cdn.prod.website-files.com/...bc6a057dc9e037f5_1*roMpPdHWeLp0huNd_r-K0Q.png

It depends on several factors, and while what you’re saying might be partly true, it’s not entirely accurate. The link you shared seems to explain it well. Let me know if you’d like help breaking it down further!

 

[groper]

Here’s a link to our social media page whit shows the construction of a fiberglass solar arch / dingy davit . It’s a quick montage of 30 seconds or so .
We achieved what was required by using much thicker beam sections than what you would need using metal or carbon . The higher section modulus makes up for thr lower material modulus - that’s how you design the problem. And This was the look we were going for , we wanted it to look kind of like a spoiler on a car with aerofoil section posts to keep it looking sleek… supports a 2400 x 1300mm 550w solar panel and a 3.1m RIB.

Log into Facebook https://www.facebook.com/share/r/1Ct37EPb2z/?mibextid=wwXIfr

 

[TeddyDiver]

It depends on several factors, and while what you’re saying might be partly true, it’s not entirely accurate. The link you shared seems to explain it well. Let me know if you’d like help breaking it down further!

Talking about breaking it down Radar Arch Fail - Cautionary Tale - Cruisers & Sailing Forums https://www.cruisersforum.com/forums/f117/radar-arch-fail-cautionary-tale-150797.html Bad engineeering whatever material never works.

 

[wet feet]

Talking about breaking it down Radar Arch Fail - Cautionary Tale - Cruisers & Sailing Forums https://www.cruisersforum.com/forums/f117/radar-arch-fail-cautionary-tale-150797.html Bad engineeering whatever material never works.

Not a lot of triangulation visible, is there?

 

[TeddyDiver]

Not a lot of triangulation visible, is there?

Apparently it broke of the hull but you right and that might have made the difference with it..

 

[Michael11]

Talking about breaking it down Radar Arch Fail - Cautionary Tale - Cruisers & Sailing Forums https://www.cruisersforum.com/forums/f117/radar-arch-fail-cautionary-tale-150797.html Bad engineeering whatever material never works.

I see your point about bad engineering being a major factor. Materials matter, but poor design or execution can lead to failure regardless. The thread you linked is a good example—did you have a specific takeaway from it?