Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1
    Join Date
    Mar 2019
    Posts
    28

    Default Foamed-in buoyancy

    Thinking of doing this to replace the odd lumps of foam which count as buoyancy in a Mk1 Shrimper. Anyone done this recently? Any advice as to which foam?

  2. #2
    Join Date
    May 2018
    Posts
    9

    Default Re: Foamed-in buoyancy

    If you mean pouring 2-part expanding foam into the tanks I wouldn't recommend it unless you can isolate the foam from the structure of the boat.
    On one boat I saw treated this way the foam bonded incredibly well to the inside of the hull, and then over time (a couple of years) it started to shrink, distorting the hull. It was a hell of a job to cut it out.

  3. #3
    Join Date
    Jan 2007
    Location
    River Trent
    Posts
    2,415

    Default Re: Foamed-in buoyancy

    Definitely NOT expanding foam, as it's not closed cell.

  4. #4
    Join Date
    May 2007
    Location
    Cambridge, UK
    Posts
    6,156

    Default Re: Foamed-in buoyancy

    Quote Originally Posted by Trundlebug View Post
    Definitely NOT expanding foam, as it's not closed cell.
    Some is, for example https://www.ecfibreglasssupplies.co....ne-foam-liquid, which I used in a dinghy.

  5. #5
    Join Date
    Jun 2007
    Location
    Benfleet Essex
    Posts
    1,123

    Default Re: Foamed-in buoyancy

    It may say closed cell but ask any boatbuilder worth his salt, it isnt. All of it soaks water up eventually. Horrible stuff.

  6. #6
    Join Date
    Oct 2012
    Location
    Devon, England
    Posts
    2,557

    Default Re: Foamed-in buoyancy

    I wanted a flat floor to two small lockers in a dry part of my boat, up forward, so I used 2-part expanding foam and fibreglassed in a ply panel on top.
    Reasonable results.
    Though it was quite hard to make the top surface flat, needing several applications to fill in the gaps.
    (I didn’t dare to use it in a closed compartment for fear of it bursting it! Though I suppose I could have measured the volume.)

  7. #7
    Join Date
    Apr 2005
    Location
    Shoreham - up the river without a paddle.
    Posts
    1,225

    Default Re: Foamed-in buoyancy

    Empty plastic water bottles are clean and easy to remove if time takes it's toll. Likewise wine bags and they tesselate better.

    As suggested above, I have had many an unpleasant day cutting out o.e. waterlogged foam.

  8. #8
    Join Date
    Nov 2011
    Location
    Nelson New Zealand
    Posts
    586

    Default Re: Foamed-in buoyancy

    If i was a potential buyer of your boat and i saw poured in foam I would walk away. I too have seen what can result with waterlogging and distortion.
    Aiming to live forever or die in the attempt!

  9. #9
    Join Date
    May 2001
    Location
    North Wales, sailing Aegean Sea or Menai Strait
    Posts
    21,966

    Default Re: Foamed-in buoyancy

    Years ago I made a lot of grp canoes and filled the ends with two-pack polyurethane foam, supposedly closed-cell. The canoes were used by youth groups, so suffered considerable exposure to water. After a couple of years the foam was utterly saturated and it took me a great deal of effort to dig it all out. Professionally built canoes use polystyrene buoyancy for good reason.
    Answers to some technical queries at new website http://coxeng.co.uk

  10. #10
    Join Date
    Nov 2016
    Location
    Lincoln
    Posts
    886

    Default Re: Foamed-in buoyancy

    Have you looked at dinghy buoyancy air bags, loads of differing shapes and sizes and not too costly

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Latest YBW News

Find Boats For Sale

to
to