DIY Stainless frame for solar panel

[walt]

I want to add a semi permanent about 40 watt single solar panel up fairly high above my aft railing. Sort of like what is in this picture http://members.tripod.com/~lbucko/index-2.html

To do this, I'm going to have to build the tubing structure to mount to my current ss rail (which is a fair amount lower than where I want to put the panel). It seems that to do this, you cant just "order" what you need, everything must be fabricated - i.e., all the tubes, fittings to connect tubes, etc. I may have to go this way but am wondering if anyone knows where you can can get any of the hardware? Some of the bimini hardware might work. I know some very crafty people build there own fittings to interface the tubes but they have better machine shops (and more skill) than I do.

Any source leads or ideas appreciated..

 

[flhunterowner]

How about Mcmaster Carr @ www.mcmaster.com

you can get all sorts of tubing either raw or with connectors in either alumn. of ss.

 

[Ron20324]

Sailrite.com has a bunch of fittings, and can send you the bow kits to your measurement. Yes, some assembly required. Defender is cheaper than West for the fittings.

 

[Alan Johnson]

I have made two set of frames for different boats I have owned. The last frame was bent of 1" ss tubing and I used a plumbers pipe bender. Fill the pipe with sand and it will be less likely to kink. I used standard 1" bimini hardware, did some crossbracing, works great.

 

[sailingdog]

Harbor Freight sells a pipe bender that will work with most 1" or 7/8" stainless steel tubing. Draw the plans up and then do a full-size mockup using EMT conduit before making the commitment to use the stainless steel.

 

[sand sailor]

mac 26s

this means you have a pop top correct just mount it there.
unless you live on it I dont think you need a panel that big on my boat i have an 8watt from harbor freight and it does fine keeping the batteries charged

 

[SamLust]

www.outdoortextiles.com Better pricing than McMaster, probably broader selection of tubing and fittings. They can be a pain in the neck and still can't figure out how to pack tubing for shipment. One order of tubing arrived without the tubing. They're still worth a look.

 

[walt]

All very useful info to me, thanks!!!

I put a battery monitor in the boat this spring and have learned a lot of things about my electrical system because of it. I already have a 20 watt panel mounted on the deck in front of the mast and will probably keep it there along with the 40 watt panel. One thing which has been very interesting is seeing what a little bit of shading does (once again, Ill give credit to Sailing dog for pointing this out to me). The other day, I had a 5/16 diameter rope going across the panel in direct sunlight and this reduced the output by 25 to 30%. A little bit of shade on the corner of the panel does the same. In my opinion, putting the panel in a good location is the single most important thing you can do in a solar install. For example, you can spend a lot of money on a MPPT controller vs just a PWM controller but end up gaining more actual battery charging by simply better placement of the panel.

I also found out that in general, my 20 watt panel hardly keeps my system charged even when the boat is "turned off". I had a bunch of small loads which were on 24 hours a day like my stereo memory voltage, I left a hand held VHF charging pluged in and my AC converter is the type which draws a little current even when its off. I’ve added switches to all these so that I can turn them completely off but before this and with not worrying about partial shading, the limited day charging of the 20 watt panel was barely keeping up with the 24 hour per day leakage.

Anyhow, how much solar panel size you need very much depends on personal use and I think a 40 watt panel mounted in as good of location as possible for a trailer sailor will work well for me (my kids use most of the power..). The location way to the rear and up high seems a good place (on the pop top will have huge shading from the boom). My rail mount barbeque will need to safely fit under the panel so that will partly determine the height and also, I keep my mast crutch permanently mounted in the back and I want to minimize the shading from the mast crutch.

 

[sailingdog]

Walt—

One thing to consider is the normal position of the boat, if it is at a slip, or the direction of the prevailing winds, if it is on a mooring. Place the panel based on what location will be unshaded for the majority of the time. If your slip opens to the south and you back into it, then the stern location for the panel may be less than optimal. Likewise, if your slip faces north and you back, having the panel on the stern is a good idea.

Shading is a huge problem, and one that is often overlooked.

 

[Heaven Net]

70cmx45cm timber 2 lengths 214 cm 2 lengths 81cm mitred grip fixed and screwed to form the frame to house your solar panel.

2 lengths of 3x5cm to support galvanised corrugated sheet sides

I standard corrugated tin roof sheet (recycle centre £5.00) overcharged me IMO J

Black foam backed reflective foil faced thermal lagging (lucky find in recycle centre £2.00) This is used on the underside of the corrugated steel sheet to prevent heat escaping from the back of the panel. (pictures to follow)

Perspex cover sheet. A used aluminium window and frame can do the same job. This is to provide a heat retaining shield to let the energy in from the sun and prevent the heat escaping from the mat black painted corrugated sheet an copper tubing carrying the domestic hot water.

2x 3meter lengths of 22 mil copper tube
6x 3 meter lengths of 15 mm copper tube
16 x 22mm reducing Tees to 15 mm middle outlet fittings
4x 22 mm elbows
2 15mm sockets to join offcuts to save on copper tubing requirements.


Make wooden frame mitre the ends, grip fix or wood glue and screw ends together

This should be made so that the corrugated sheet fits inside with ease, the bottom and top edges of the sheet are cut with tin snips and bent to a right angle. Screws can be hammered through the thin sheet to secure the top and bottom.

The 2 lengths of 3x5cm are nailed flush with the edge of the frame on both sides. The corrugated sheet is inserted and secured by hammering screws through the sheet, best done with a screw driver and hammer, then wizzed up with the powered screw driver after you have lagged the back of the sheet with the reflective foam backed lagging. This way the tin sheet secures the lagging and the sheet in one go. Allow sufficient lagging to hang over the sides of the frame so that the Perspex/ glass lid can be secured to form a nice weather proof gasket.

Once the frame is lagged and secured with screws along the sides and the snipped corrugated ends of the sheet are folded over these can be secured again by driving the screws through the thin sheet into the wooden frame with a hammer.

Now for the soldering bits n bobs.

The 22 mm tube is for the outer edge fitting inside the timber frame sides, top and bottom, with an outlet via a Tee converter at the bottom and on the top at the opposite side giving maximum distribution of the inflowing cold water (bottom) and out-flowing hot water (top opposite side)

Each corrugation on the tin sheet will have a 15 mm copper pipe joined at the top and bottom by a reducing Tee fitting. Repeat until all corrugations have a 15 mm pipe. When all the soldering is checked for leaks under pressure by linking to the mains via a jubilee clip and hose pipe or whatever method you choose and you are certain there are no leaks.


Spray paint the sheet surface and pipes with mat black heat resistant stove paint or exhaust paint. This is going to get hot quickly.

The idea is using aerosol paint we can have a very thin mat black surface to maximise heat transfer to the water inside the tubes.

Secure the Perspex / glass lid in place and couple it to either an indirect heating system or a direct heating system making sure there is an expansion tank on the system to take care of increased pressure building up as the water expands when heated and does not compress. I used plastic lugs shown in picture to secure the perspex sheets as they are prone to crack if drilled and screwed

Adequate lagging and an outside isolating stop cock and drain plug for those freezing winter nights might be a worthy consideration.

My system hopefully will run solar heated water back to my combi boiler, which fingers crossed should not have to fire up and if it does fire up will shut off once the heated water reaches the internal thermostat. Though on sunny days, we should have hot water with the boiler turned off.

Early days yet and more modifications may be required, but thought you might be interested in this project designed to supply our hot water needs.

This total build is costing under a hundred pounds!

My philosophy is if I put a hundred pounds in the bank, by the end of the year, given the pathetic interest rates and poor performance of the pound against the euro, I will probably have lost money.

Here my hundred pounds will earn me money every time we have some moderate sunlight.