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

[Will Gilmore]

I would first need to know what it is you are trying to do.
Simply mounting solar panels doesn't cut it.
I can tell you I would consider flexible panels instead, mounted directly to an existing deck surface.
Although, finding an area with unobstructed exposure to the suns rays would be a priority
as even a rope across a panel can result in significant voltage drops and inefficiencies.

Doesn't your response sort of support the arch just for solar panels idea?

This example is bulky and overkill for a high wind structure to secure solar panels. But an arch offers the best unobstructed exposure to Sunlight. The problem with sailboats and solar panels is that sailboats have great massive big wedges of sunblocking cloth sticking up in the air.

As far as hurricane force winds on an arch, the biggest problem will be the panels themselves. I suggest installing them with an easy snap-on snap-off bracket and plug to remove quickly when a big storm approaches. Hurricane force winds can sneak up on you with a sudden, but short bust, but you're much more likely to see it coming from miles away and the Sun will probably be hiding before then, so stow your panels below. Your panels will thank you and so will your helm.

 

[fallguy]

Probably on the order of 12",8",4" tabbing all around, so 6",4",2" on each side...should add

Also, straight vertical supports generally need some 45 degree or so cross supports or you'll get into some rough seas and the thing will move a bunch on top and something might break.

Curious about the roof of the cabin unless you are going all in on lotsa solar..

 

[BlueBell]

Doesn't your response sort of support the arch just for solar panels idea?

It does indeed but no graphics are shown of what is proposed.

 

[mariobrothers88]

Thanks for the help guys good thing I didn't build the rest of the posts yet ill change it single 2x4s for the posts with 45 degree cross supports.

 

[solhagoli]

I'm thinking of using 1 layer of 17 oz biaxial fiberglass, but wanted to get your expert opinion as well
hellodear.in

teatv.ltd

 

[groper]

i recently built this solar panel support and dingy davit for our yacht which previously had nothing on the transom. I used foam and glass, nevermind the wood!
Sorry i dont have close up photos at this time, this pic was taking before we fit the solar panel on top.
The 10mm solid fiberglass base plates were drilled and thru bolted thru the transom to attach it and later joined into the stainless pushpits to provide lateral stiffening. Another way of doing it would be to use long fiberglass or carbon tubes which go right thru the transom and glassed into the hull bottom thus offering a cantilever support between the hull bottom and transom thus negating any further support visible externally.
It was rather time consuming compared to making it from metal tube in the usual manner, however it just wasnt the look we were going for. The whole thing weighs about 20kg + the solar panel and we hang our 3m RIB off it aswell

 

[starcmr]

Doesn't your response sort of support the arch just for solar panels idea?

This example is bulky and overkill for a high wind structure to secure solar panels. But an arch offers the best unobstructed exposure to Sunlight. The problem with sailboats and solar panels is that sailboats have great massive big wedges of sunblocking cloth sticking up in the air.

As far as hurricane force winds on an arch, the biggest problem will be the panels themselves. I suggest installing them with an easy snap-on snap-off bracket and plug to remove quickly when a big storm approaches. Hurricane force winds can sneak up on you with a sudden, but short bust of residential solar panels, but you're much more likely to see it coming from miles away and the Sun will probably be hiding before then, so stow your panels below. Your panels will thank you and so will your helm.

The dinghy I'm building needs a removable centre thwart, generally this would be made from a plank of wood. I don't have a decent bit of wood, so perhaps against my better judgement, I'm toying with making this out of a foam/glass/epoxy composite. My thinking is that I can make it much chunkier, yet lower weight, and it can add a bit of reserve buoyancy in case of swamping. If it turns out to be a disaster I can just build a wooden one as per the plans. I also have some ideas about making a solid bimini top and this seems like a good way to get my eye in with the materials and techniques. Approximate dimensions would be 1.3x0.3m and as deep as I care to make it- maybe 75-100mm. It sits on top of a bulkhead so would need a slot moulded in to accommodate this. Seeing as it's supported from underneath, it doesn't really have to be all that strong. Would I be along the right lines if I used a single layer of 300g/m2 cloth? Laid up using a sheet of smooth plastic to give a good surface, then paint finish. It's not a critical item so I kind of hoped that I could use more or less any type of closed cell foam as the core. Epoxy, seeing as that's what I've got. I'm a total newbie with this so happy to accept any and all advice.

 

[fallguy]

Not polystyrene. Marine foam; perhaps.

 

[wet feet]

I would double that 300gsm otherwise the impact resistance will be terrible and things do get dropped in dinghies.A good foam might only need to be 12mm,but wouldn't provide much flotation.Poylstyrene isn't a particularly "good" foam in structural terms but it can work over such a large area-there are experimental aircraft wings that use hot wire cut polystyrene as a core.The greater volume of polystyrene will obviously provide more buoyancy which means that you need to be careful to secure the new part so that it can't float away if the boat is swamped.

 

[C. Dog]

After a fair bit of mucking around with wooden boats, a major point of failure in timber is holes, screw holes, staple holes, skin fitting holes and so on. Experts are saying to overbore, fill with epoxy, then rebore to fix this issue.

 

[wet feet]

After a fair bit of mucking around with wooden boats, a major point of failure in timber is holes, screw holes, staple holes, skin fitting holes and so on. Experts are saying to overbore, fill with epoxy, then rebore to fix this issue.

It's true that any hole can be the origin of trouble but over boring and then adding an epoxy layer won't prevent leaks through the hole in itself.The gap between a thread form and the hole can form a helical leak path and needs to be filled with a suitable mastic to block off the path for water.There are those who add a small countersink-say 1/16" wide to all holes to allow for a collar of mastic at the surface of the part.The technique can also be useful for preventing flakes of gelcoat popping up when using self tapping screws.

 

[fallguy]

I would double that 300gsm otherwise the impact resistance will be terrible and things do get dropped in dinghies.A good foam might only need to be 12mm,but wouldn't provide much flotation.Poylstyrene isn't a particularly "good" foam in structural terms but it can work over such a large area-there are experimental aircraft wings that use hot wire cut polystyrene as a core.The greater volume of polystyrene will obviously provide more buoyancy which means that you need to be careful to secure the new part so that it can't float away if the boat is swamped.

Always people overinterpret this type of comment.

What airplane wing used 25 pound shear rating xps?

Even the Rutan work used higher shear rated cores, if that is what you mean. And those aircraft were not made to withstand even a bird impact. Far different than a removable thwart that gets used for all sorts of stuff.

 

[wet feet]

Always people overinterpret this type of comment.

What airplane wing used 25 pound shear rating xps?

Even the Rutan work used higher shear rated cores, if that is what you mean. And those aircraft were not made to withstand even a bird impact. Far different than a removable thwart that gets used for all sorts of stuff.

Why not ask the EAA for details?This from their website:

Foam is usually the choice of material for the custom aircraft builder. Foams are easy to shape and reasonable in cost. Three types of foam are generally used within our industry. Polystyrene foam is the first. It is blue in color and is supplied in large billets. Polystyrene foam is often used to construct boat docks. This type of foam can be easily shaped using a "hot-wire" technique described later in this article. Polystyrene foam is the type used in several popular composite airplanes in the wings and control surfaces. It does have the disadvantage of being softened by exposure to gasoline and several other solvents. This type of foam cannot be used with polyester or vinyl ester resins both of which will be discussed later.

 

[C. Dog]

@wet feet in Gary Dierking's "Outrigger Canoes" book he discusses using epoxy to seal and retain both self tapping threads and metal threads in over bored epoxy holes in timber.

Surely though any amateur boat builder worth his salt knows about sealing things that go through or into boat timbers?

The point of failure I alluded to was wood rot rather than a few drips of water down an extremely narrow helical path.

 

[wet feet]

I would regard the wood rot as another manifestation of the same thing;a consequence of water getting into the structure.If our composite structure has a balsa core and moisture enters,that will definitely rot and from time to time people find this forum to ask for advice on curing the situation that results.In principle drilling oversize and then adding resin is much the same as applying a coat of un-thinned resin with a fine brush pushed into the hole in that it provides a seal to isolate the core,A few people are conscientious enough to dip woodscrews in varnish on wooden parts and this also locks them in place very effectively.I doubt that you would find anybody now who dips keelbolts in white lead paste to ease driving them through floors and keel.

An oversized hole,or removing some core by using a bent piece of wire in a drill and re-drilling is the usual way to provide crush resistance if a fitting needs to be located in a place where a hard insert wasn't moulded in.The hole that gets drilled will still have some gap around the thread form and will still need sealing.I would hope everybody understands the necessity of a mastic around the upper portion of a thread and not just around the perimeter of the hardware but I think it worth mentioning for those who have never considered the matter.