A25 - solar on the coach roof

[WillieC]

I know $90 sounds expensive (said the guy who salvaged a 40 year old piece of marine plywood for my new swim platform that has already been repurposed two times and soaked in saltwater for most of its life) but anytime you hire a guy trying to make a living, its going to be at market rate. And good for him. I spent my good working years as a union electrician and could never have afforded to hire myself. Then again I had no use for six one megawatt diesel generators all synched together with automatic transfer switches in the event of utility power failure. But every now and then I needed to add a light fixture or an outlet. Point is, I have over the years learned to do just about everything there is to do on a boat and then I bought one when I retired. Boat ownership is expensive, I do my best to do it myself. And sometimes that can bite.
Nice looking brackets, as long as they do the job.

[DesertAlbin736]

Well, if you're going to through bolt anything through fiberglass, (for example as the grab rails are), I would say drill the holes a bit bigger diameter than the bolts you plan to use, then fill the holes with epoxy. Let the epoxy cure, then drill the holes through the epoxy for your bolts. And of course caulk the bolts appropiately. That way you seal the core, which on the A25 cabin top is about 1 inch (2.54CM) thick foam. The epoxy I'd recommend would be West System G-Flex, which is a two part ready to use gel that comes in two small tubes the size of a toothpaste tube, resin & hardener mixed 1:1 ratio for small batches. G-Flex is available through West Marine or most online chandleries.

gflex.jpg

Otherwise I'd start looking for flexible solar panels, a number of which are sold online.

[Sunsetrider]

DA - Well I won't be looking for another panel since my 260W single panel is sitting on my coach roof (unsecured) as we type. I have been reading Don Casey's deck hardware comments which correspond to yours, and that is the method I will use - although we have different product availability up here in the still-frozen north, so I will be satisfied with a LePage's 2-part epoxy that I already have. But what I am wondering is:

Instead of a thru-hull bolt (through a drilled hole filled with epoxy) why not simpy drill a pilot and screw a SS screw into the epoxy plug? Instead of a bolt? With appropriate caulking of course. Seems like the epoxy core will provide a satisfactory medium to hold the screws, hmmm? What do you think? I like to minimize the bolt heads lining the cabin celing.

[DesertAlbin736]

"Instead of a thru-hull bolt (through a drilled hole filled with epoxy) why not simpy drill a pilot and screw a SS screw into the epoxy plug? Instead of a bolt? With appropriate caulking of course. Seems like the epoxy core will provide a satisfactory medium to hold the screws, hmmm? What do you think?"

Yes, I suppose that sounds feasible, as long as the screws don't work loose from vibration & they're large enough not to pull out. If it didn't work out you could always go the next step to through bolts, nothing ventured, nothing gained.

[Beta Don]

If the deck is cored (especially if the coring material is end grain balsa) I would drill fairly large holes to fill with epoxy - The screws will try to break the epoxy and that could provide a path for water to wick into the coring material

IMO, thru bolting would be preferred for something as large, bulky and heavy as a 260 watt solar panel. That panel will put quite a load on it's mountings

Don

[Sunsetrider]

OK - some progress today. The pics speak for themselves I guess. Despite Beta Don always urging the more thorough approach, I have gone ahead on drilled 1/4" bit one inch deep (measured from the top of the flange), stopping short of piercing the cabin ceiling. I filled the 1/4 in. holes with 2-part epoxy and am leaving them overnight to cure. Tomorrow I will secure the clips with a one inch #10 SS screw, after spreading epoxy between the (composite) shim segments and Life-stuff as a bedding. I will chamfer the holes. After all is stable I will trim the shims.
FYI the decking is 2 cm thick below the outer skin.

If there is a failure to hold I will report back. But I think it will be OK.

PS - It was the PO who decided to strip and paint the grab rails. Bad idea.

20170702_121307Clip Pre-shim2.jpg

[DesertAlbin736]

Seeing the pictures, my only concern with a panel that big and installed that way might be what could happen in the case of a strong wind in a storm getting under that thing. Or likewise trailering down the road at highway speeds of 100 km/hr, like having the hood on a car not latched & being blown open like a big sail. That's a lot of square footage, (or square meter as it were) and a lot of force/stress generated on those screws if a big wind gets under it. Maybe I'm being paranoid, but it's something to consider. Guess we'll have stop by to check it out when we drive through Ontario & Quebec in the fall.

A good winter project would be to pull those painted hand rails, bring them indoors, strip them back to bare wood, sand, then start with 2 or 3 coats of clear epoxy resin followed by an additional 3 or 4 coats of spar varnish, then make a set of Sunbrella covers to protect them. That would look really Bristol & the covers would protect the finish.

[DesertAlbin736]

Don,

Deck coring on the coach roof is a dense foam material 1 inch thick, not balsa, having seen it when changing out a Nicro roof vent.

[Sunsetrider]

I don't have a trailer, sad to say, but I would strap around the panel if I did.b

I will keep a close eye on the security of the attachments as we go, and am prepared to replace the screws with bolts if need be. That will not be a major operation. As it is the panel has been sitting on brackets (holding it above the roof) unsecured on the deck of 2 weeks in windy conditions at the dock. It has not budged over that time. And of course the speed of the boat will not add greatly to the wind pressure.

I did give a brief try at removing the grab rails last year, but was unable to remove the fasteners from below with moderately strong force. I don't want to cause damage to the attachment system. I'll slowly sand away from time to time.