Mounting Panels on Flexible Hard Top

[thinwater]

I have a fairly strong hardtop (FRP/foam over 1" thick) that I intend to mount 2 panels on; however, it does still flex measurably when folks walk on it.

Has anyone considered mounting the panels at only 3 points to insure they cannot be twisted or stressed by the distortion of the deck? Alternatively, I could build a stiff subframe. I suspect all of this is unnecessary since the flexing is perhaps 1/8" over 4', but I thought I would ask.

[S/V Alchemy]

If it can take the weight of people, two circa 27 lb. panels (the weight of a Kyocera 135 W) are not going to do much.

Given the number of secured objects I've seen go off the boat due to chafe, wear, corrosion and "loose nuts", I think three points might be optimistic.

[thinwater]

Originally Posted by S/V Alchemy

If it can take the weight of people, two circa 27 lb. panels (the weight of a Kyocera 135 W) are not going to do much.

Given the number of secured objects I've seen go off the boat due to chafe, wear, corrosion and "loose nuts", I think three points might be optimistic.

It's not the weight, it's the flex. I wonder what the effect of flexing might be on the cells, long term.

Well, only one forestay holds the mast! But I haven't seen the frame on the panel and can't guess how it would feel about point loads.

[Cotemar]

thinwater,

A little flex will not be a problem. The aluminum frame on the panel will spread it over the whole panel. Most installations of solar panels are on a bimini with 1’ ss tubing which flexes also and sailors have been doing that for years now.

No worries doing a four point contact

[boatman61]

Depending on where you mount them you may find they act as a stiffener... those frames are pretty strong on quality panels...

[SailFastTri]

What size panels? There are semi-rigid panels that don't have glass surfaces (poly) and are thinner and lighter. Check out the Ganz 30w units, for example.

[Mark Johnson]

Where ever I mount solar panels I usually use side rails made out of Starboard. (They can be on the ends or sides). It allows them to be mounted to surfaces of a variety of shapes, the beveled rail ends keep the panel from snagging lines, and mounting them with good air circulation underneath keeps the panels cooler. This produces more V and better charging.

These have survived 150 MPH winds as well!

Best of luck with it, Mark