what to use for insulation

[Don Hayes]

I will be traveling in the colder parts of the world part of the time Canada and Alaska what works for insulation? Look forward to any help I can get on this.

Don Hayes

[Jeff Kittle]

I am sure there are better ideas and info out there, but....On our boat we used the plywood/corecell foam sandwich construction for the deck. We don't get condensation on the inside of this. On the walls and on the bow/stern areas where there is no sandwich construction we get condensation. I forget how to spell corecell. We got ours from Noah marine in Canada. If you don't need structural strength other foams would be less expensive. I would check to see what kind of foam the Clements used because I think they found less expensive foam.

[Jeff Kittle]

Also look at the 5th entry on the "Where do they rot" Thread for their foam.

[Ann and Neville Clement]

We have a friend who fell in love with Arctic sailing in the north of Norway. When he looked at our Tiki 46, he commented that if we ever wanted to sail in cold climates, we could easily make one hull into a heated living area for eating and sleeping and insulate the inside of the hull skins with cheap styrofoam 20 mm sheets cut to fit temporarily inside between the stringers. I must admit that our friend had glorious photographs of the Arctic, but it is not the kind of sailing everyone would want. Nev will not go where it gets that cold for very long although we often have a few days of freezing temps at night during our annual migrations and wait for warm enough temps to melt ice on deck before sailing off in the morning. Condensation is a problem inside the boat in extremely cold conditions without insullation on the sides of the boat. Our decks are insulated as per plans and do not have condensation problems.

I sailed my old uninsulated monohull in snow and ice and blizzards years ago from New York to Cape Hatterass and the major problems were condensation running inside the boat with resultant mold growth, slippery decks which were a danger, and frozen lines making sail adjustments difficult. I put old plastic box lids in the backs of lockers to keep clothing etc free of the running condensation and I used a lot of salt on my deck to keep the ice problem under control and shoveled snow without damaging the decks by using a plastic dust pan. Lacking any heat, I just kept adding thermals under normal sailing clothes and kept fairly warm with three pair at once sailing through a blizzard which was not predicted.

The real solution to all these problems in my opinion came when I gave up coastal sailing in those conditions and simply sailed offshore from Beaufort, NC crossing the Gulf Stream in hours, and arrived in Bahamas three days later wearing shorts and tee shirt 90 % of that leg of the trip.

My Arctic sailing friend had the type of heater that did not add to the condensation and other folks will know better about that topic. He wintered in the extreme north of Norway quite happily one year but admitted to wearing his Union Suit all winter long.

We have lovely photos of wintering in Bahamas.

[Kevin Redden]

I am doing some of the research on building a Pahi 63 myself and I live in Maine. IT gets cold and wet here alot. Here it is August 24th our summer It is cold outside and I am wearing a winter blanket. I put some of my research I got from some pros and what I know and put this together:

To stop condensation in a cold-molded epoxy plywood boat, I haven't quite got the ventilation down yet)

Why Condensation Happens

• Wood and epoxy hulls get very cold in the water or cold air.

• Warm air inside the boat hits the cold hull and turns into water drops.

• Trapped water can rot wood or break the epoxy bond over time.

Best Insulation Methods

• Closed-cell spray foam: Seals the hull completely and stops air from touching the cold wood. It also adds strength and floats.

• Closed-cell foam boards: Cut panels to fit tightly between frames. Glue them down with epoxy or polyurethane adhesive with no gaps.

• Avoid open-cell foam or fiberglass batt: They let moist air pass right through, trapping water against the wood and causing rot.

Stopping Moisture and Rot

• Leave an air gap: Put thin wooden strips (battens) over your insulation, then attach interior panels (ceiling liners) to them. Air must move through this gap.

• Seal all wood first: Coat every piece of plywood and framing with unthickened epoxy before you insulate.

• Add vapor barriers: If using rigid boards, tape all seams tightly so warm cabin air cannot reach the cold hull.

Ventilation and Airflow

• Install cowl vents or solar fans: Keep air moving through the boat day and night.

• Use passive vents: Put low-level intakes and high-level exhaust vents in every cabin.

• Run a dehumidifier: Use a small marine dehumidifier when living aboard or storing the boat in damp weather.

I hope it helps. I have been doing lots of research different boat manufacturers and I'm looking into spirit yachts cause threir build system is very similar. They have  a cold molded approach.I will let you know what else I find. i plan on running heat and Ac due to health issues.