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Critter
03-17-2009, 08:48 AM
A little bird tells me that protective covers will be required for windows larger than 2 square feet. Can anyone suggest a clean and effective approach to building and attaching these?

I'm visualizing epoxy-coated plywood panels cut slightly larger than the windows, and blind female-threaded inserts epoxied into holes drilled through
the fiberglass around the window. The panels would be bolted to the inserts, maybe with thumbscrews.

What I can't picture is dragging this panel out onto deck when it's already blowing pretty hard, and fumbling with screws to hold it down. Besides which, my boat partner always grumbles when I talk about drilling more holes in the boat.

Any better ideas?
Max

BobJ
03-17-2009, 09:04 AM
Past SHTP rules required "Storm Coverings for all windows more than two square feet in area, unless the windows are constructed of material at least as strong as the surrounding superstructure."

If the Long Pac rules get worded the same way (and they should IMHO), are you sure you'll need coverings?

Critter
03-17-2009, 10:42 AM
The wording is the same. I think my windows are 1/4" acrylic - maybe 3/8" - so I guess I'll start by measuring the surrounding fiberglass and crunch some numbers to compare the strengths.

tiger beetle
03-17-2009, 01:20 PM
I'm visualizing epoxy-coated plywood panels cut slightly larger than the windows, and blind female-threaded inserts epoxied into holes drilled through
the fiberglass around the window. The panels would be bolted to the inserts, maybe with thumbscrews.

A simple way to meet a rule requiring a storm covering is to carry plywood pre-cut to cover the window(s), stored below.

You do not need to screw the plywood to the boat to cover the hole left by a missing or destroyed window. Instead, use a pair of wooden cross-members on the inside of the plywood that are used to clamp the ply to the cabin. The cross-members might 1"x2" wood with a bolt run through from the outside of the boat, thru the plywood, through the cross member, with a wing-nut on the inside end of the bolt (epoxy or clamp the outside bolt head to the plywood).

If the window fails you can usually push the plywood through the (now missing) window and into place from inside the boat, pull the plywood in against the cabin side, rotate the cross-members to contact the interior of the cabin, then tighten up on the wing nuts - clamping the plywood in place.

It won't stop all the leaks, but will prevent a wave from washing in through the window. When conditions improve, if you're keen on reducing leaks, you can go topside with a drill and run holes through the ply and cabinside and screw the ply to the cabinside with machine screws. This will damage the fiberglass, but that may be a minor issue at that point.

I would not pre-drill holes in the boat to accept storm coverings, unless you had 1/8" automotive glass windows...

And as Bob says, the rule should require storm coverings only in the event that large windows are made of material NOT as strong as the surrounding fiberglass. I'm using 3/8" lexan windows thru-bolted to the cabin - and the material meets the rule. The problem windows are those made of glass set in weak aluminum frames, and thin acrylic windows.

- rob/beetle

Critter
03-17-2009, 01:41 PM
Thanks Rob! The penny has dropped. See, I was picturing a preventive measure: "Bad weather coming Martha, we'd better get the storm windows on!" You're saying that this is something to block the big hole after my windows are smashed. Makes much more sense.

Alchera
03-17-2009, 07:11 PM
Two square feet is pretty large - do you really have port windows that are larger than that?

- Mark

Critter
03-17-2009, 08:51 PM
Two square feet is pretty large - do you really have port windows that are larger than that?

Hi Mark. Yup, there's just one long window each side. They're only about 8-9" tall if I recall correctly, but 5 or 6 feet long.

It's a long time since I got my mechanical engineering degree, but I think the short span of the window is a more critical factor for failure than its area. Any chance of revisiting this rule, Rob? Ruben?

Max

tiger beetle
03-17-2009, 10:32 PM
It's a long time since I got my mechanical engineering degree, but I think the short span of the window is a more critical factor for failure than its area. Any chance of revisiting this rule, Rob? Ruben?

Nope, no chance. A window 5-6 feet long, even if only 8-9" tall, represents an enormous hole into the boat's interior - if that window fails then a particularly bad wave can fill the boat in short order. The value of a plywood/crossmember/wingnut design storm cover is the skipper is protected from the elements while installing the cover (you stay inside the boat) and no tools are required other than your fingers to operate the wing nuts.

If you think the existing window material isn't as strong as the surrounding structure then I'd strongly recommend skipping plywood storm covers and instead upgrade the windows by installing a storm window. In effect this is what I've done by removing the original 1/4" acrylic material and replaced it with significantly stronger 3/8" lexan (polycarbonate), thru-bolted, purchased from Cadillac Plastics in San Francisco (I think TAP also carries lexan these days). I'm already sailing around with the storm covers installed, no need to tell Martha to get out the preventive measure storm covers as they're in place from the get-go.

- rob/beetle