Use Strong Magnets to Mount Flexible Solar to Bimini??

[canman]

I have experience using rare earth magnets to temporary hold flexible panels until we could use a more permanent method -. They worked very well until we hit 45-knot gusts! so we quickly installed Stay Puts through the canvas with great results - both the shock cord version and lockable ones through eyelets in our panels. Used a 1/4 inch awl they sell to create the holes in canvas. https://www.sailrite.com/Shock-Cord-Cover-Clip-Black
https://www.sailrite.com/Stayput-Can...astener-Black-

[Pete7]

Originally Posted by ikanode

My experience with magnet hold-downs in similar situations suggests that they're not very good at preventing slip-sliding sideways creeping movement over time. A combination of velcro and the magnets would prevent that.

I'm not recommending magnets for your use just suggesting other factor to consider.

Agreed. The tank bag on my motorbike is held in place with magnets and doesn't move. However, for flexible panels I have always used velcro for the past 10 years.

Not sure I would use Reflectix because it requires an air gap to work. Instead how about something like this to provide an air gap and some ventilation?

https://www.wickes.co.uk/Wickes-10mm...500mm/p/246000

[roberthowell]

so how would create a space to mount a flexible panel on a hard top without it becoming flappy

[valhalla360]

How does the strength of the magnets change with spacing.

They may have a 100lb strength when magnet to magnet with nothing between them.

But how much will remain if you coat each with a thick layer of epoxy, plus canvas plus the solar panels. I'm just guessing but that could be 1/2" of spacing which could significantly reduce the force the magnets can generate.

Otherwise with a few details addressed, sounds viable.

[canman]

We used double stick foam tape so only one layer of fabric separating the magnets

[Pete7]

Originally Posted by valhalla360

How does the strength of the magnets change with spacing.

They may have a 100lb strength when magnet to magnet with nothing between them.

The bar magnets on my tank bag are about 1"x3" in length and there are six. I can easily straight pull them off the tank individually.

A 1.5" circle of pre-glued velcro is a sod of a job to peel off needing patience to work from the edge bit by bit.

Pete

[Salty Possum]

I installed a flexible panel on my Bimini as follows. I sewed and glued a 2.5 inch disc sunbrella patch on top of the Bimini under each of the solar panel grommets. I then sewed 1.5 inch nylon washers using No 4 Robeline to the underside predrilling 1/16 holes. The panel was the attached using 316 ss 1/2 inch No 10 machine screws and washers with cap nuts on the underside. It seems secure but I haven’t seen more than 29 knots since it was attached. I considered sewing the edge of the flexible panel to the canvas with a rolling stitch but haven’t seen wind trying to get under it yet the way it did when it was just tied on. I made sure that I can remove the Bimini without taking the panel off of it because I do stay in the Florida Panhandle for hurricane season. This summer it was off-on-off-off-on. I am not recommending this but okay so far. Ask me in five years how it worked out. I am afraid of strong magnets on my boat.

[mawtty]

Flexible solar panels can be mounted on rigid curved surfaces.
Not good to have them flex on a canvas bimini.
They wont last long that way.
I put mine over stiff curved hardtop with 25 mm ss tube supports.
Also left 25mm space for air cooling.
I hope they will last for a year or two.
I also used sikoflex to bond round rubber spacing between the panels and the rigid hardtop,
putting the spacers under the gaps in the solar cells.

[Siberian Sea]

Is there a chance the magnets will rust and then leave big rust stains on your canvas? Maybe you could use something like “Tool Dip” to encase the magnets I’m not sure.

[Popcorn]

If using Magnets in an array, the field you may create may affect your navigation equipment, compass and other items. A magnetic field may be slight even from 2 meters away but could cause major miscalculations in your navigating calculations, especially influencing a fluxgate compass. Consider ties, clamps or something else and be safer.

[Sunsetrider]

Originally Posted by mawtty

Flexible solar panels can be mounted on rigid curved surfaces.
I put mine over stiff curved hardtop with 25 mm ss tube supports.
Also left 25mm space for air cooling.
...
I also used sikoflex to bond round rubber spacing between the panels and the rigid hardtop,
putting the spacers under the gaps in the solar cells.

I am planning similar on the cabin top of my Riviera. Plenty of other more comfortable places to lounge on! But I don't understand what you mean by the 25mm ss tube supports - can you be more specific? Or pictorial?

[mawtty]

OK Sunsetrider. I use the ss tube to keep the curve in the hard top, which is purposefully built to shade the aft cockpit seat.
Sorry, I don't know how to insert an image (URL?)

[Sofa King Fishy]

You’ll likely need to adjust your compass, The deviation might be impacted?

[kirklkjb]

Magnets may be good for a temporary good weather application. I would use magnets when the boat is on the hook and only in good weather. Dynamic and wind loads can be quite large. I would not use tie wraps either as they degrade in the sun and fail with no warning. Velcro can work given enough wraps. We use a velcro strap to secure the clew on our J80 main and the loads are quite large. Our velcro strap is 1" webbing with fuzzy velcro stitched on one side and the hooks stitched on the other that can be looped multiple times. Talk to a sailmaker they use velcro loops all the time for clew hold downs.

[David Mathis]

Three issues:

1. You want to attach to a Bimini frame with magnets. The Bimini frame is stainless. Depending on the type of stainless, the magnetic attraction may be slightly diminished, significantly diminished, or just about nonexistent. A strong breeze, or maybe even a not so strong one, may take your device into the depths.

2. Supermagnets have a super strong field. This equates to having the ability to reach out and touch your compass at considerable distance as well as being able to have an adverse affect on electronic circuits within your devices. Also for consideration, when you decide to remove it, will it be stored in a place to minimize the effect of the magnetic field on your devices?

3. The metals in a supermagnet are reactive to acids, bases, and salts. The tiniest void within the paint or other coating will result in flaking and severe corrosion. When you can see even a tiny bubble in the paint, the metal is already being corroded.

Velcro sounds like a better attachment method.