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RigBig · 15-11-2021, 05:00

Is there anybody here with direct experience with securing solar panels on top of a bimini with so called high strength rare earth magnets?

AndyEss · 15-11-2021, 17:54

I’ve had direct experience of flexible solar panels having very poor life. I do have experience with plastic cable tie mounting of solar panels - works fine for smaller panels.
What will all those hi-strength magnets do to your compass readings?

Junglebike · 15-11-2021, 20:17

I have four Renogy 175W panels on my Sunbrella Bimini (41' CHB trawler). They work great. They are very easy to remove - I take 2-3 of them off when I'm not cruising (most of the year) and leave the last one to keep the batteries topped off.

I used magnets with a threaded stud through the panel grommets with washer, lock washer, and nut. Six per panel. On the underside of the bimini I just have a magnet.

I wouldn't want them up during a gale, but I wouldn't want my Bimini up in a gale either. The alternative (hard top bimini, hard panels) would have been massively expensive and added a lot of weight way up high. The current setup cost very little, and with 1/2 the panels being stored under our master berth they should last a long time. If not I'll buy new better panels in a few years - still cheaper. I think it's a great solution for our use case. If I were living aboard I *might* put some hard panels on a frame over the davits instead. I like being able to quickly take them down with the bimini and store if a storm is coming.

Oh... and no problems with compass readings.

prvelero · 16-11-2021, 07:28

Who makes this magnets? ty

Junglebike · 16-11-2021, 08:13

Quote:

Originally Posted by prvelero

Who makes this magnets? ty

I got them from Amazon but there are other sources:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...e?ie=UTF8&th=1

tamicatana · 16-11-2021, 08:44

why? Just get, from McMaster-Carr, nice cheap light easy durable nylon bolts and nuts. Mine, holding my flex panels to my bimini, are in something like their 7th year and going

https://www.mcmaster.com/nylon-bolts/

Junglebike · 16-11-2021, 08:47

Quote:

Originally Posted by tamicatana

why? Just get, from McMaster-Carr, nice cheap light easy durable nylon bolts and nuts. Mine, holding my flex panels to my bimini, are in something like their 7th year and going

https://www.mcmaster.com/nylon-bolts/

Curious how you penetrate the bimini fabric & whether you need to do any sewing/reinforcing - what I like about the magnets is that they don't leave a hole in the fabric.

tamicatana · 16-11-2021, 09:07

fabric has sewn reinforcement vinyl patches at the perforations, which have grommets. The screw heads cover the holes. Have held up in blows. pas probleme

I would not be interested in the complexity, weight and possible compass interference of the magnets

Junglebike · 16-11-2021, 09:12

Quote:

Originally Posted by tamicatana

fabric has sewn reinforcement vinyl patches at the perforations, which have grommets. The screw heads cover the holes. pas probleme

Thanks - I might go that route sometime down the line; the magnets worked well for me to get the panels up there quickly so I could verify that the panels met my needs. I know a lot of people are on the fence about solar, so I often recommend them as a fully reversible, cheap, and easy way to get started.

Letterkenny · 16-11-2021, 09:21

Quote:

Originally Posted by Junglebike

I have four Renogy 175W panels on my Sunbrella Bimini (41' CHB trawler). They work great. They are very easy to remove - I take 2-3 of them off when I'm not cruising (most of the year) and leave the last one to keep the batteries topped off.

I used magnets with a threaded stud through the panel grommets with washer, lock washer, and nut. Six per panel. On the underside of the bimini I just have a magnet.

I wouldn't want them up during a gale, but I wouldn't want my Bimini up in a gale either. The alternative (hard top bimini, hard panels) would have been massively expensive and added a lot of weight way up high. The current setup cost very little, and with 1/2 the panels being stored under our master berth they should last a long time. If not I'll buy new better panels in a few years - still cheaper. I think it's a great solution for our use case. If I were living aboard I *might* put some hard panels on a frame over the davits instead. I like being able to quickly take them down with the bimini and store if a storm is coming.

Oh... and no problems with compass readings.

Any issues with rust or the heat affecting the canvas? My friend and I are both considering this as we do not need panels 24/7 and more just on occasion. Realistically, I probably don’t need them at all but it helps with the battery anxiety. My main concern is that it’s a brand new and expensive Bimini and dodger so I just want to make sure those are protected first and foremost.

Junglebike · 16-11-2021, 09:28

Quote:

Originally Posted by Letterkenny

Any issues with rust or the heat affecting the canvas? My friend and I are both considering this as we do not need panels 24/7 and more just on occasion. Realistically, I probably don’t need them at all but it helps with the battery anxiety. My main concern is that it’s a brand new and expensive Bimini and dodger so I just want to make sure those are protected first and foremost.

No issues with rust or heat. After 2.5yrs of full time exposure there are a few faint rust spots on the magnets, but nothing that would stain. I think there are rubber-coated magnets available as well if you prefer. Certainly if you pulled the panels off when not using the life of the magnets before corrosion set in would be extended.

Letterkenny · 16-11-2021, 10:58

Quote:

Originally Posted by Junglebike

No issues with rust or heat. After 2.5yrs of full time exposure there are a few faint rust spots on the magnets, but nothing that would stain. I think there are rubber-coated magnets available as well if you prefer. Certainly if you pulled the panels off when not using the life of the magnets before corrosion set in would be extended.

Can you link to the magnets that you used?