Lining with closed-cell foam for floatation, insulation, and safety

  • 03 Dec 2019 16:06
    Reply # 8166591 on 8148577
    Anonymous member (Administrator)

    I meant a stove dedicated for heating. However, I have seen postings here showing a makeshift heater with a flue, occupying one of the two burners of a cooking stove. I fear that at least half of its energy escapes up that flue.

    My needs are modest. I only make day-sails, these days, and then choose the fine days. During winter I often visit the boat and then light a little gas heater, which makes use of all the heat, and quickly brings up the temperature.  However, without a flue, this has no de-humidifying effect.


  • 03 Dec 2019 15:04
    Reply # 8166168 on 8165821
    Arne Kverneland  wrote:

    A stove with a flue does wonders in drying out a boat, but is difficult to find space for ...

    Just to be clear, do you mean a cooking stove or a heating stove (or both)?

    Here's a picture of Bill Churchouse's stove on Belgean, a Westerly Nomad (22') and Jester Challenge boat.  If he can do it, perhaps so can I.

  • 03 Dec 2019 14:14
    Reply # 8165821 on 8148577
    Anonymous member (Administrator)

    About keeping the boat dry and warm inside.

    When I bought my IF, Ingeborg in 2014, she had recently gone through a big refurbishment inside. All the hull and deck  -  and I mean all  -  had been covered with about 5mm thick insulating (foam-like) lining. In addition, the windows had been given new frames (one can buy spare-parts for the IF). There were two small leaks. One came through, or rather beside a through-hull, up close to the gunwale (don’t ask me what it was meant for), and this leaked behind the foam lining, when I sailed the boat a bit hard. The other was a few drips coming through a deck vent.

    The through-hull was easily fixed, once identified, but it took a while before I noticed the few drips from the deck vent. Still, even those few drips, was enough to make the climate rather damp inside. When I replaced that ventilator, things got better, and the boat now has dust-dry bilges. That makes the whole difference. Now, with good ventilation and no drips anywhere, the climate is fine. I don’t have the specs for the foam material, but it would not surprise me if it insulates as well as 10-12mm wood  -  that is, a lot better than naked grp. Unless you plan for 80°N, Roger Taylor style, I see no reason for adding more insulation than that.

    Sooo, hunt for leaks first! A dry bilge is the goal. Niceties, like avoiding un-covered cold metal (cold-bridges) here and there could be next step. A stove with a flue does wonders in drying out a boat, but is difficult to find space for ...

    Good luck!


  • 03 Dec 2019 12:02
    Reply # 8164818 on 8164523
    Arne Kverneland  wrote:

    Safety against sinking (in an ‘ordinary’ boat) is all about improving odds without making the boat useless in the process.

    We are in agreement. This is an odds-improving exercise.

    Thanks for your list of safety priorities. These are all things I have on my list too, but it is very helpful to get an idea of where other people see the main dangers.

    I don't want to give you all the impression that unsinkability is my biggest obsession or I see sinking as my main danger.  Far from it!  It just happens to be my project for this winter.

    The reason it's my project for this winter isn't actually because I'm setting off across oceans imminently or that I expect to sink soon. It's actually because Tammy Norie could really do with the insulation, and this is a three-birds-one-stone project.  And if I'm going to get all three birds, I want to get the stone right.

    PS: Would it be an idea to approach Roger Taylor about how to best ‘offshorising’ Tammy Norie?

    That's on my list. Roger's description of the sinking of the replica Endeavor in Voyages of a Simple Sailor is somewhat of an inspiration!

    Last modified: 03 Dec 2019 12:03 | Anonymous member
  • 03 Dec 2019 11:21
    Reply # 8164523 on 8148577
    Anonymous member (Administrator)

    in my view, there is no such thing as a perfectly safe boat - or a perfectly safe life, for that matter. The matter of  modifying a boat to make it unsinkable (and floating in an upright position), is not easy. If that were a must, I would rather look for a boat which has already been built for it from the start.
    Safety against sinking (in an ‘ordinary’ boat) is all about improving odds without making the boat useless in the process.

    First priority for me would be to make sure that all the hatches, washboards and windows stay put and keep big green water out in case of a knock-down. Even better (for comfort) would be to make the hatches ‘submarine tight’, but these may be awkward in everyday use.

    Collision with logs or containers.
    The odds are that such damages will be in the bow section. Instead of using foam. I would divide the volume below the forward berths up in 8 – 10 compartments, using a set of small bulkheads, glassed to the hull. All the cavities would have top plate firmly glued on and all of these would have some sort of watertight hatch in them. This lets you store light stuff there.

    Another big safety hazard is fire.
    Since we tend to use liquid fuels, these must be stored securely. The choice of fuel for cooking, and the practice when refilling the stove, must be as safe as possible.

    Good navigation and keeping a decent lookout to avoid hitting rocks and ships, is also a noticeable safety factor.

    Then, by ensuring you don’t fall over board, or get injured by being tossed about, you should stand a good chance. Standing a good chance is what it is about. As said, total safety doesn’t exist.

    Frankly, to me, simply sinking due to a hole in the bottom, seems to be one of the least risks.


    PS: Would it be an idea to approach Roger Taylor about how to best ‘offshorising’ Tammy Norie?


  • 03 Dec 2019 11:01
    Reply # 8164390 on 8148577

    Yachting Monthly trying to sink an unsinkable Etap 21 . Worth reading to see how slow and undramatic it is in calm conditions. Also confirms that all the buoyancy is below berth level.


    "Etap is the only builder of unsinkable yachts and is currently (2007) seeking a Lloyds certificate to that effect. Sadler Yachts used to have a claim to this title before it ceased production but, according to the only standard of unsinkability (that of the French Merchant Marine), unsinkability means that freeboard is reduced by less than 3% of LOA when flooded. Sadlers, though they wouldn’t actually sink, would flood close to deck level."

    The article also has much to say about disaster proofing, including bulkheads, airbags and pumping.

  • 03 Dec 2019 09:37
    Reply # 8163758 on 8163522
    Graeme Kenyon wrote:

    Sorry Richard, I missed one of the posts and had not realised you had an ocean passage in mind. I admire the level of detail in your thinking and your quest for information and ideas, wish you success in your project - and look forward to the video!

    Think nothing of it! I don't expect everyone to know all my plans. In fact, it goes to show how I ought to be a bit clearer about the overall campaign idea and write that up.  I've recently got well enough to start writing down many of the thoughts and ideas I've had over the past few years, so that's a useful point. I'm sure some of them are misguided and feverish!

    Any further thoughts you have are very welcome.

  • 03 Dec 2019 08:59
    Reply # 8163522 on 8148577

    Sorry Richard, I missed one of the posts and had not realised you had an ocean passage in mind. I admire the level of detail in your thinking and your quest for information and ideas, wish you success in your project - and look forward to the video!

    Last modified: 03 Dec 2019 09:13 | Anonymous member
  • 03 Dec 2019 08:27
    Reply # 8163314 on 8158884
    Richard wrote:

    On the subject of mono- vs multi-hull unsinkability, I met a couple in an Etap in the Netherlands who told me a story about a couple of lads who opened all the seacocks in their Etap then sailed it around (slowly).  Unfortunately, like many sailing stories, it's impossible to verify.  I had a good look at their Etap and a lot of the floatation seemed to be quite low down.  But this has reminded me to research both the Etap and Sadler designs.

    Etaps and Sadler 26 and 29 can be sailed in flooded condition, yachting magazine articles have been written about it, and I think this depends on them devoting much of the volume below berth level to foam between the hull and inner lining. Worth having a close look at both of them. I remember going aboard a Sadler 29 and being concerned about how tiny the stowage bins under the berths were, and how, though it was a lovely sailing machine, I couldn't contemplate long-term cruising in one. I also think that to get to this "sail her home" or "recover from total flooding" state will require buoyancy of at least twice the displacement.

    Twice in my sailing career I've been in a water over the cabin sole situation. The first was when I did a bad job of installing a paddlewheel log  - so 100% peace of mind, which is what you seem to be aiming at, means taking it and glassing over the hole. Who needs a log anyway? The second was when I didn't realise that water was coming in through a ventilator in the anchor locker when I was bashing hard into a head sea. That could have resulted in loss of the boat if I'd not stopped in time, hove to and started to bail out. The proverbial "frightened man with a bucket" can do a lot more than a bilge pump can, particularly if there's debris to block the pump, but there comes a point of no return where it's impossible to get the water out faster than it's coming in. I believe that you would need more than twice the displacement in floatation to be sure of not reaching that point of no return.

    I didn't put foam below the chine on Tystie because she's wooden, and visual inspection for deterioration is more important than it is for GRP. I wouldn't want sprayed on foam in a steel or alloy boat for the same reason, but maybe with GRP, getting someone to spray some foam on would be a lot quicker and easier than gluing on bits of sheet foam.

    "I explained some of this plan to my friend Richard over breakfast. He has some very useful comments:

    1. Once the boat is insulated the amount of condensation appearing on the remaining cold spots is likely to increase: the hatch, the windows, metal frames, etc. Perhaps this is another good reason (apart from plan.osmosis-prevention) not to insulate below the waterline: cold surfaces in the bilge will act as a dehumidifier."
    Yes. Tystie has double glazed windows with no metal frame, and the washboard is a ply/foam/ply sandwich, but that still left the alloy-framed perspex deck hatch as a major source of drips. It needed secondary double glazing in the winter. An alloy mast will need a nice knitted jacket, as Arne has on his. There was much more condensation right out in the ends of the boat, where there was little heat and ventilation. But I don't buy using the bilge as a dehumidifier. Good ventilation is important to keep condensation at bay, and I suggest one or two Air Only vents.

    Trying the Jester Challenge, eh? I thought about doing it in Weaverbird, and decided tha I couldn't carry enough water, though a stop in the Azores or a hand pumped watermaker would fix that. But in a smaller boat, half full of foam, austerity would be taken to a whole new level.

  • 03 Dec 2019 06:03
    Reply # 8162358 on 8148577

    On the subject of unsinkability a couple of examples come to mind. Back in the 1950's (?) there is of course the story of Tzu Hung which capsized en-route to Cape Horn and lost most of the above deck superstructure. Miles Smeeton, John Guzwell and the rest of the crew managed to keep the boat afloat and make landfall in South America. This story of real and great seamanship is recounted in the book Once is Enough. (I think I have got the title correct).

    The other not so good example is a very recent yacht sinking off our northern New Zealand coastline a couple of months ago with the loss of one life. A yacht was returning from Fiji to New Zealand and got caught up in some extreme weather such as we have in New Zealand during the spring. Based on media reports the yacht was overwhelmed by very large waves and lost some or all of the cabin windows. the crew were unable to keep up with water ingress and the yacht sank. I will be very interested to read the eventual reports and find out the full story. It is hard to imagine how any well built offshore yacht could suffer such a loss of watertight integrity so it will be interesting to find out the size of the windows and how they were attached.

    Last modified: 03 Dec 2019 06:04 | Anonymous member
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