Fiberglassed PVC as Solar Arch

[ttex]

Thoughts on the viability of making a solar arch out of 1" pvc pipe and then wrapping layers of fiberglass around it another half inch of thickness?

Or something along those lines?

I know I can do it I am just wondering how strong it might actually be...

I can't stop thinking about boat stuff.

[cj88]

You can buy fibreglass tube if that's what you want. Google for pultrusions or pultruded profiles.

[hpeer]

Here is a good start

https://championfiberglass.com/wp-co...ifications.pdf

[hpeer]

Steel tension strength is 53,700 psi
Aluminum is 45,000
Fiberglass 7,000

I built an arch out of 1-1/2” schedule 40 electrical conduit. That has a wall thickness of 0.138” vs 0.25 noted above for the extra heavy fiberglass. I’ve no clue if what you suggest could be made to work.

I think if I were to do it again I would look to aluminum. Aluminum conduit seems to dimensionally similar to schedule 40 galvanized steel conduit.

[model 10]

Resin doesn't stick to pvc. Use foam pipe insulation as the form.

[ttex]

I just mentioned it to my Dad and he thinks it is a terrible idea, he actually seemed angry....

[Emmalina]

Originally Posted by Ecos

Resin doesn't stick to pvc. Use foam pipe insulation as the form.

Yes it does just sand with 80grit first. repaired many a tank and kayaks with epoxy !

[motion30]

I agree fiberglass will adhere to pvc. Personally. I would go bigger, 1.5" seems about rite

[clockwork orange]

Originally Posted by Ecos

Resin doesn't stick to pvc. Use foam pipe insulation as the form.

Actually both VE and epoxy resin stick quite well to properly prepared pvc. This means you have to abrade it and wipe it clean just like any other material with a smooth surface. Epoxy in particular will bond many materials such as steel and aluminum with proper preparation. I quite often use pvc pipe wrapped with glass as well as lots of G10. You can bend pvc pipe easily with a heat gun to form shapes before glassing.

Steve.

[Suijin]

A lot of this depends on the weight of the solar panels and the geometry of the arch. Yes, you could probably do it, but the question is how long it will last. Sounds like you want to do it on the cheap. And on the back of a Baba 35 you are limited in terms of where the feet go, the geometry, etc. If you just want to fart around coastal then it will be fine. If you want to head offshore it will not be fine. Get/make a real arch with suitable rigidity.

FYI I've seen a large number of "ghetto arches" made as you have presented and they just don't last. You need a strong enough skeletal structure, and if you have that the fiberglass on top is necessary.

[Jim Cate]

So, OK, you can glass over PVC pipe, and you can bend it into weird shapes if you want. That's cool, but how are you going to do the engineering on t he structure? Solar arches take a lot of loading... static weight, windage, wave strikes and inertial loads when the boat is pounding. With a structure built up of homebrew materials like glassed PVC pipe, getting it strong enough to survive is questionable IMO. My guess is that you will end up either with some overbuilt monstrosity or one that fails at sea at an awkward moment... and that has a pretty good chance of being as ugly as a mud fence.

I think I side with your Dad!

Jim
Edit: I see that Suijin and I were typing similar posts at the same time... obviously two great minds!

[Chotu]

There is no point in it. As has been said before, there are pre-fabricated fiberglass tubes of all profiles as well as aluminum to work with. Aluminum is even easier.

You need to analyze what loads the arch will experience. Most arches I see aren't made out of tubing at all. They are flat panels. If made from aluminum tubing, the tubing is arranged into small multiple runs that approximate a flat panel.

I'd say you're over thinking it.

Look at using a foam core and glassing up an arch out of 3 flat panels. Dead simple to make compared to a messy and ugly paper mache type project wrapping wet out glass around PVC.

[Minggat]

If you watched how my SS arch moves under the weight of my panels, the idea of anything lesser strength might be less appealing. If I had seen it, I would have built it with more beef.

After watching it sway back and forth day after day on a long passage, I finally took 2 ratchet straps and made an X between the uprights. Instant rigidity.

[Cadence]

Originally Posted by ttex

I just mentioned it to my Dad and he thinks it is a terrible idea, he actually seemed angry....

Your Dad sounds like a smart fellow.

[DerekKelsall]

Originally Posted by ttex

Thoughts on the viability of making a solar arch out of 1" pvc pipe and then wrapping layers of fiberglass around it another half inch of thickness?

Or something along those lines?

I know I can do it I am just wondering how strong it might actually be...

I can't stop thinking about boat stuff.

We have used PVC tube in many different ways - to cap overhanging c'roof, supports for sunroof, as ladder and support . The edge of an open hull on small boat. Either wrap in fiberglass or just fixed by injecting filler in the case of capping. As X-beam for proa. Try making fiberglass tube on PVC. Cover with parcel tape. Lay on one layer, slit to remove, wrap the tube in thin string and replace on tube. Masking tape across the slit and then build up to thickness. 1/8 in will do most jobs. Pull out the string and the grp tube slides off. Mostly we would use 1.5 - 2 inch pipe. Sand the PVC pipe to get a fair bond.

Happy boating, Derek.