Storm Boards - Window Protection

[Diamond-Esp]

I will be taking my yacht across the bottom of the Pacific to Chile (when we are eventually allowed to get out there again). I am located in southwest Australia and would go via Tasmania and New Zealand. The yacht has all the systems onboard for such a trip, but the biggest concern is the size of my cabin windows. They are custom made with tempered glass, due to their size I would be looking at having storm boards made.

The yacht will be spending time in high latitudes over the coming years, so I am also considering using the storm boards to reduce internal condensation. At this time, I am considering having polycarbonate made up slightly larger than the current windows and fixing to the hull with aluminium Rivnuts into the hull or current window frame. I would place neoprene or similar material between the frame and polycarbonate to allow cushioning and make a waterproof air gap.

I would appreciate any feedback or ideas on the best method. I would prefer not to make the storm boards out of any material I can't see through as the all round view from inside the cabin is wonderful. I had considered solid aluminium with several slots but only as a last resort.

I have attached (hopefully) a picture of the yacht to show the window size.

[LouK]

Just a small consideration here- if you seal the polycarbonate all around, you will definitely have condensation trapped between the two pieces of glazing because one cannot evacuate the air in the gap. Similarly, thermally insulated windows have a vacuum pulled between the panes of glass & thus no condensation is possible . However, a basic storm window has openings at the bottom to let air and moisture evacuate- you’ll get condensation & then it will sublimate, but not be trapped. From a thermal perspective, a storm window is about 65-70% effective as an insulated glass window. You’ll want an air gap of no less than 1/2”.

[noelex 77]

If correctly specified, the windows should be capable of coping with all wave forces, but in the spirit of belt and braces we had the factory install backing plates with tapped bolt holes so aluminium storm covers can be attached in the event of breakage.

See the photo below with all the aluminium storm covers in place.

I doubt the storm covers will ever be needed, but the tapped holes also facilitate the easy attachment of external shade covers or an additional plexiglass insulation layer for extreme enviroments.

[Diamond Life]

LouK, thanks for the advice, I had considered holes on the bottom to allow trapped moisture out. Thanks.
Noelex- I have looked at photos of your great looking yacht before and considering solid aluminium. I would like to leave mine on for most of the trip so considering something I can also see through otherwise aluminium makes perfect sense.

[Manateeman]

Ports in our hull had 1/2” alu welded blocks inside. They were drilled and tapped to take exterior Lexan storm shutters. Our four forward pilot house fixed windows slant aft but are 30”high. We went with laminated glass and welded drilled and tapped blocks on the exterior. The shutters are 316 stainless sheet with top hat horizontal reinforcement bars. The air gap is about an inch. We use street bolts which have a big head. Keeps the sun out. They are not very heavy and we store them in the engine room. The pilot house side glass is 22” high. Three panels each side. Laminated glass. No storm panels yet. Maybe never. The companion way has a horizontal power slide laminated glass. It’s 1” thick. My paranoia again about ice bears.
Laminated glass has issues in the Florida sun. Some Frosting on the edges. Looks like winter snow. The French glass claims to have solved the issue. Time will tell.
Condensation. Thin self adhesive neoprene helps but the eight dorade pipes drip sometimes We have thought about thin plexiglass interior panels with epdm or neoprene gaskets and filling the gap with argon through a foam needle like a football valve. We might replace all the large Bomar Ocean hatches with our own design as their gaskets shrink and Bomar couldn’t care less. So much for extruded hatch frames. Expensive junk. Protect your largest openings.
When we were building, I talked a lot with fishermen in Alaska and Norway. It’s easy to overbuild and if you just take their advice based on a lot of experience, you will be OK. Buy a BIG self powered dewatering pump...Bring a plywood panel and 1/4” self drilling screws and some 2x4s. There is a great video of a ice bear trying to smash his way into a research boat and eat the crew who didn’t think he could climb on board. Wish someone could find and post it. See, that’s one problem you won’t have
You have a strong boat and are obviously a prudent Mariner so you will be fine.
Happy trails to you.
Mark and his spoiled manatee crew who think pizza will satisfy the ice bears.

[fourlyons]

Originally Posted by LouK

Just a small consideration here- if you seal the polycarbonate all around, you will definitely have condensation trapped between the two pieces of glazing because one cannot evacuate the air in the gap. Similarly, thermally insulated windows have a vacuum pulled between the panes of glass & thus no condensation is possible . However, a basic storm window has openings at the bottom to let air and moisture evacuate- you’ll get condensation & then it will sublimate, but not be trapped. From a thermal perspective, a storm window is about 65-70% effective as an insulated glass window. You’ll want an air gap of no less than 1/2”.

Just a quick correction... If you actually seal the polycarbonate completely you will NOT have condensation. That is how thermal windows work, they do NOT have a vacuum pulled between the panes, they would collapse if so. Instead there is always either air or other gas mixes injected into the space.

[LouK]

My friend, you are mistaken regarding insulated glazing units. A slight vacuum /negative pressure is drawn just after the edge seals & spacers are applied. The better windows have an argon fill. Building a DIY insulated glazing unit is not the purview of most mortals and as an architect, if I had a dollar for every window I’ve designed, specified or replaced, I wouldn’t be sailing a 30 yr old boat).

LouK

[Katapult Mike]

OP, I don't have the answer to your question but I really like the look of your boat! Is it a one-off, production boat, or what? Can you share any info on the design, designer, yard where it was built? Love the windows and the hard dodger, like to know more.

[Diamond-Esp]

Mike, she is designed by Jean-Pierre Brouns from the Meta Chantier Naval yard in France. It is a Strongall design meaning she has few bulkheads below. 8mm Aluminium on the bottom and 6mm on the deck and cabintop. I believe that if you look up JPB 32 you will get additional information as she is very similar. Easy to sail with everything back to the cockpit, perfectly setup for single handing. There are no holes/fittings on the deck (except 5 hatches for ventilation) so she is completely dry below, no through hulls fittings, just a few standing pipes in the bathroom area for toilet inlet and seawater inlet for washing etc. She has a sail drive but that area has an enclosed structure, although the engine has the best access ever. The cabin seating is reasonably high so you can see all around whilst sitting below. She is my fifth yacht, I started with fibreglass and lots of timber, now I have a yacht with minimal maintenance, she is a work boat.... built to go sailing..

[nuku34]

To the OP,

off your topic, but the photo of your boat doesn't seem to show any obvious provision for a storm jib stay or staysail stay. Looks like the only headsail is th roller furling jib.

With respect, if I were going into the high latitudes, I'd have at least a staysail stay (could be removable). A solent stay with hanked-on "blade" is also a good idea in those latirudes.

On topic: 10mm polycabonate storm shutters would do the trick with rubber strips all around, but I'd leave some gaps in the rubber on the bottom. I guess alloy rivets are ok, but to get the shutters off you'll have to drill out the rivets. Maybe s.s. machine screws?
BTW I had a steel "Joshua" made by Meta in 1973. She went to the Antartic before I owned her. Lapstrake round-bilged hull, great method of construction.

[Don C L]

I sailed a boat long ago that had channels bolted around the large portlights, well, lights actually, (Downeast 38) and there were panels of Lexan that slid into them. Seemed pretty good to me. As you may know there is greater danger to lights when a boat falls off a wave, and lands on leeward side, than a wave coming over the windward side. Pretty rare occurrence, but still wise to be ready for it.

[Diamond Life]

Thank you for your responses. In regard to the inner stay, I have recently installed the mast and deck fittings and the inner will be 8mm dyneema SK75. I have a storm jib (GaleSail) and will also have an additional No 4 for the inner. I am still looking at all options for fixing the boards,so thanks for information. I have looked at channel’s around but decided against it due to window size.