Solar arch - thinking out of the box

[maine-cruiser]

Originally Posted by sailormed

There are marine solar arch manufacturers out there. I found several, this is one of them:

https://www.atlantictowers.com/products_sail_arch.php

no personal interest.

edit: same posting time, see now du bist in Deutschland.
You have Nautinox in Italy closer by.

I have an Atlantic Towers tower installed on my Catalina 355. We installed it ourselves. It is the Schedule 80 version that was $2400 in 2019 and is now $3300. I use it for solar but you can also use it as davits with some accessories added. Shipping would be a killer I'm sure to Germany.

[Muaddib1116]

https://www.youtube.com/watch?v=RkofrhRjVqY

This doesn't look all that bad. I would probably rivet everything once it was set up. I don't know if this would be adequate as dinghy davits, but it's possible with enough tubing, deck fittings, and end connectors, possibly throwing in some stainless u-bolts, that you could make it robust enough.

[Madehn]

Had my arch and dinghy setup made to my specs by a fabricator whose primary job was making SS industrial kitchens. Made from 2 inch SS tubing. Super secure and super sturdy. It holds solar radar horns vhf antennas and wind generator. Sides are made in ladder shape to strengthen and to facilitate climbing up so service anything. Lower part of legs are 40 inches apart and serve as structure to hold grill and fx85 fortress stern anchor. Assembly is held to deck by 8 3/4 inch thru bolts to large under deck plates. Each leg with 2 bolts. It is large but so is the boat. Fabricator had never done anything like it and enjoyed the challenge. Was hard to move on to deck but looks good. Suggest you make bottom fairly square rather than try to match deck angle then mount on to teak blocks which can be sanded to match deck angles precisely. I would stay away from flexible panels imho too fragile and seem to have short life spans but your boat your choice. Taking a drawing to fabricator is a must. Don’t expect them to come to boat to measure etc if you want to keep costs down. Best of luck.

[JC Reefer]

Tower In A Box has some nice products. A bit pricey but worth considering. A bit ironic to offer an in the box solution for an out of the box post. [emoji51]

[hpeer]

So I made a solar arch our of Schedule 40 1-1/2” galvanized steel conduit. Electrical conduit. Buy it at some electrical contracting distributor. For the 90° bends I used stick elbows. I cut the conduit and treaded it to accept standard couplings. Made up some deck sockets, took it to the boat and assembled it there. Once on the boat I adjusted the couplings for correct fit and the welded the thing up in place. It needed some stiffeners which I made out if 1” thinwall conduit, I just beat the ends flat and mounted them with a conduit hanger. Complete price, 10 years ago, was well under $500 US.

It actually looks pretty good. I have made some changes but the basic form is OK. Heavy as hell.

From this, it may be possible to do something similar in aluminum. or even possibly using SS conduit.

I suspect the structure is waaay over design for load capacity.

At very worst you could do something similar, using cheaper materials (thinwall) to come up with the basic design. Then take it to a fabricator and have him build it.

I am now out for an estimate to duplicate this arch in SS or aluminum. I am very happy with the fundamental design. I want something lighter that I don’t have to maintain.

Not so much a recommendation as a tale, sharing my experience.

Re: Atlantic Towers
I knew someone who installed one on a 48’ish Jennau with a swim platform. It looked sorta OK, but when I put my hand on it, it moved all over the place. The attachment points were very loose. I could not tell how much flex there was in the structure because the whole thing was not really sufficiently fixed to the boat. I know the fellow who installed it and his work is generally above average. Good reputation. But I would not have trusted this arch. I don’t know which version, schedule, it was. Just the attachments were very poor.

I don’t generally go around grabbing other peoples arches so I don’t know if this was normal or not. It was vastly different than what I have on my boat.

Just an observation.

[Celestialsailor]

Originally Posted by CarlF

Is this just a solar arch or do you plan to also hang a dinghy? If the former, it's much easier. You don't need much strength and the solar panels are aluminium framed so corrosion is no problem. Hanging a 400lb dinghy is not really an amateur project.

Make it from aluminium 6061 tubing. Cheap and easy to cut. Take your cut pieces and a drawing to a metal fabricator far from the ocean. Even better, cut thin plywood with the wood the same width as the tubing that he can use as a form for bending. He'll bend the tubing and weld. Paint it yourself - being meticulous about prep and primer. Will last as long as the paint on your aluminium mast. The welder will be able to put bases on - although best to build a mockup on the boat to get the base angles right.

Here's an example of a welder near me. "ABC Welding". The "ABC" strikes me as a good sign that the pricing will be reasonable

https://abcweldingservice.com

6061 has temper to it making it difficult to bend. A more suitable aluminum would be a 3000 or 5000 series aluminum.

[Celestialsailor]

Originally Posted by synonym

Hi all!
So firstly thanks for the many answers in such a short time!

I should have mentioned: it will have to function as davit as well. The tender is 90 kg including motor and fuel.

@double U: Thanks for the feedback on the pre-fab parts!

Yes, any metal worshop that has welded stainless can do it. I know. But you have no imagination how the situation is. I have been quoted 12k € (!!!) by workshops known to build arches. Workshops that don't specialize in it have quoted me 5.5k.
I got a quote from a stainless tubing supplier, the material is about 800€, ready to weld.

The issue really is, that none of the metal workshops reply. And trust me - I am my best charming self. I inquired with more than a dozen. Either they said right away they are booked or they took weeks to decide the same thing. This is starting to become a threat to our departure planning - hence my thinking about alternatives.

If we can't get this thing done, we'll have to make do with solar on the sea rail and perhaps the deck - I doubt that we can fit the wattage required, per my calculations and the dinghy would still be homeless...

I'll keep digging...

There's nothing like a good Global recession to bring humility back to manufacturing and lower prices to a point that is fair to all people...not just the rich and stupid!


Another option for the OP might be something that I do is to find one used. Where a boat has been decommissioned or wrecked or whatever. Here in US on the left coast, there are used boat part chandleries. Even if it takes a little modification you might be better ahead.

[Ballsnall]

Buy yourself a TIG welder and put it together yourself. TIG welding is extremely easy to learn and if you sell the gear afterwards it will be very economical.
You will still need to find a pipe bender but this would only be a couple of hrs work so should be a lot easier than finding a welder that will commit to a week or two.
To be honest, SS is the only game in town. Yes you can do alloy but it needs to be more substantial and the welders shill is critical.

[goboatingnow]

Originally Posted by Ballsnall

Buy yourself a TIG welder and put it together yourself. TIG welding is extremely easy to learn and if you sell the gear afterwards it will be very economical.
You will still need to find a pipe bender but this would only be a couple of hrs work so should be a lot easier than finding a welder that will commit to a week or two.
To be honest, SS is the only game in town. Yes you can do alloy but it needs to be more substantial and the welders shill is critical.

Rig is a useful skill I did a night course to learn it.

A good stainless pipe bender mandrel is very expensive

[bil56]

MPI is a good French manufacturer who has arches for many boat models

https://mpi-inox.com/en/40-stainless-steel-rollbar-mpi-

./.

[pcmm]

Another vote for Atlantic towers! We installed one 2 years ago and it was less than half the price of a locally fabricated one. That includes the shipping to Canada AND exchange rate and it was still less than half the cost of local builders!!!

[hpeer]

Originally Posted by goboatingnow

Rig is a useful skill I did a night course to learn it.

A good stainless pipe bender mandrel is very expensive

This is why I suggested SS electrical conduit, you can buy 316 pipe AND ELBOWS. Then you don’t need to bend, just weld.


FWIW I have a hard time with TIG. I run out of hands and feet and coordination. I find MIG far simpler; if not quite as pretty. If I were to do this again, with 316, I would likely do TIG, just force myself to learn.

If budget is tight then you could opt for 304 stainless. Save some money, serious money.

[bccoast]

Originally Posted by double u

I've seen "stainless-no-welding", made up from lifeline/stanchion parts (elbows, T's,...) - it looked godawfully ugly.

We were in the same boat as you. No one wanted to take on our project and if they did was insane amount of money. We have a 1.25" ss Bimini frame, I wanted to have davits and solar but decided to build one out of those "godawfully ugly" elbows and T's.

Unfortunately I had a really hard time finding 316 stainless tubing and needed to get the project done for a 8 week trip last summer. I could only get half the tubing 316 and the rest is 304. I did no polishing but after 6 months, the 304 had some surface rust starting to appear. A quick wipe with Filtz polishing creme and all came off, as well as all sorts of other rust bits on existing ss I applied it to.

The 316 ss is double the price here in Vancouver and all in spent about $600 pm the metal and brackets. I had to revise my design many times as I just couldn't find the ss brackets that I wanted. last spring was a real shortage in North America. Most of the brackets were from Florida. I also bought a great stainless tube cutter on Amazon for $20.

I have put 1200 miles on it and in rough conditions and has held up great. I would have preferred to have a bend in the solar frame so I wouldn't need the rear support brackets but there was too much flex over the 10'6" span.

Not sure if this will be a long term solution but for now has been pretty good. 2x 200w panels and a starlink post.

[jpendoley]

another vote for Atlantic Towers. I put their arch on my Pearson 365 and found it really attractive and strong.

[bluedotvoyages]

We did an aluminum structure for holding the panels with no welding. Complete info here. Aluminum parts all made before hand in a metal shop. Hope this sparks some ideas for you. Good luck. https://bluedotvoyages.com/lithium-b...ade-leopard48/