steel boat insulation

Discussion in 'Materials' started by Ambergris, Jun 29, 2018.

  1. Ambergris
    Joined: Jun 2018
    Posts: 6
    Likes: 0, Points: 1
    Location: Maine

    Ambergris Junior Member

    Hi all,
    I'm insulating my steel sailboat and would appreciate any suggestions on the best type to use. I'm building the interior so that the inside of the hull is easy to inspect.
    I don't want to use a spray on foam since I want to be able to look at the steel. (I know all the pro's and cons of foam and for me, there are more cons.)
    I've looked at products such as amercell but I believe it needs to be stuck onto the steel, which would not let me periodically inspect the hull.
    I've also thought about some kind of hard closed cell boards held in place with foam around the frames that I could remove, but I'm afraid moisture would accumulate between the board and the hull.
    Lastly, I've thought about fiberglass batting. It seems that it would be easy to remove for inspection and to form around the frames. Having said that I know batting can get waterlogged.
    I'm leaning toward using batting since I would be making regular inspections but how long before moisture becomes a problem?
    Any suggestions? Price is also a factor so preferably a cheap solution!
    Thanks!
     

    Attached Files:

  2. rwatson
    Joined: Aug 2007
    Posts: 5,618
    Likes: 231, Points: 63, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    Fibreglass batting or any kind of open cell is a bad idea, for the reasons you have stated.

    Closed cell foam sheets would be far preferable if you don't like sprayed foam. Cut to a tight fit, and inserted in between the frames. The late Tom Colvin was a fan of that technique.

    One great idea that I have seen one NA use successfully, is to apply a bituminous compound to the top of the horizontal stringers to create a sloping surface to drain off moisture into the bilges.

    I used it in a similar situation with a steel trailer that sits out in the open, and it has worked great over many years.
     
  3. Ad Hoc
    Joined: Oct 2008
    Posts: 5,713
    Likes: 249, Points: 63, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    Your best bet is to use the same arrangement that is used for structural fire protection - air gaps!.

    This is where the insulation is not attached directly onto the structure, but to a simple framework or via studs/pins. It leaves a positive 50-100mm air gap.
    The air gap adds significantly to insulating effects and also allows for any moisture water to pass over/by the structure to below into the bilges, where you generally don't have protection - just a painted bilge and the pumps!.
     
  4. M&M Ovenden
    Joined: Jan 2006
    Posts: 294
    Likes: 52, Points: 38, Legacy Rep: 527
    Location: Ottawa

    M&M Ovenden Senior Member

    Hi Abergris,
    I think you should reconsider about the "inspection" strategy. It's really difficult to achieve once you add interior arrangements. Murielle wrote up a bit about our choices here: Insulation – Building PepeBerrou http://boatmutts.ca/insulation/

    Very interesting boat - anymore info or photos you could share ?

    Cheers,
    Mark
     
  5. Ambergris
    Joined: Jun 2018
    Posts: 6
    Likes: 0, Points: 1
    Location: Maine

    Ambergris Junior Member

    Thanks, everyone! This is the first time I've tried one of these forums and some great advice here.
    Mark- The Ambergris is kind of a cross between a pinky schooner and a Tancook Whaler. Unfortunately, I don't have another picture of her on my computer but you can check out my website for a line drawing. www.discoverourplanet.com. The interior I'm building is very simple and completely open, with the storage under two setees/ berths running along either side. It's a long story, but on my last boat I was doing trips with backpackers in Central America and hauling cargo. I plan on doing the same with this boat and neither needs much in the way of accommodation!
    Ad hoc- I've thought a lot about no insulation at all and just using air gaps. I actually know of a steel boat that has been around the world 4 times now with no insulation. (Nick Skeet's Wylo) I spent some time aboard her in the tropics and it wasn't too hot. Not sure how it would be in the cold though! Probably wet but I like the idea of channeling the water to the bilge.
    Rwatson- good idea about using the bituminous compound. My last boat actually had that done and it worked well. Any thoughts about a brand for closed cell foam sheets?
    It seems Amercell is the ideal choice but unfortunately, it's not in my budget. I'm sailing south in the fall and need to spend my money on a few other details. (masts, rigging, sails, etc.) I hate to do a job twice but I'm thinking to make do with a cheaper material and get the good stuff when I can afford it. (The boat will be open and I'm building the ceiling so it is easily removable.)
    Does anyone have experience with this product?
    Boat/Marine Insulation https://low-e.co.uk/boat-marine-insulation/
    It seems similar to Reflectix which is super cheap. Not sure how well it insulates but I can stand a bit of discomfort for the short term. The main thing is to get sailing before winter sets in!
    Thanks again for all of your advice,
    ~Patrick
     

  6. rwatson
    Joined: Aug 2007
    Posts: 5,618
    Likes: 231, Points: 63, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    AMBERGRIS - Rwatson- good idea about using the bituminous compound. My last boat actually had that done and it worked well. Any thoughts about a brand for closed cell foam sheets?

    It wouldn't really matter. Stick it on straight after the paint job, and it will be cured and inert by the time you get to insulation.

    Ad Hocs suggestion of air gaps is valid, but if you put foam panels between the ribs, you end up with an air gap to the hull, because they aren't glued to the inside of the hull, just pushed in tight between frames.

    When you get to actual frames, then you need to glue the foam to the steel to get around the corners of course.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.