Stretchy skin on frame model

Discussion in 'Materials' started by alan craig, Nov 19, 2018.

  1. alan craig
    Joined: Jul 2012
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    Location: s.e. england

    alan craig Senior Member

    This experiment was inspired by a post on this forum which I cannot find now; it was a model made to test a stretchy covering and was vaguely speedboat shaped.
    I'm building a double ended model yacht hull with a stretch covering (an old tee shirt) just to see if it's a viable way of making a boat. If it seems successful I'll carry on and make it radio controlled. Size 34" long x 10" maximum beam and made of s**thousedoorwood as my old boss would have said. The wood quality cost far more in time spent compensating for warps, knots etc. than I saved in pounds by not buying anything. At least I have a pleasing shape.(not me, the model.)
     
  2. upchurchmr
    Joined: Feb 2011
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    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Neat looking test. That looks like a much better model than I would manage
    Your tee shirt material is 100 times as stretchy as a real desirable fabric. Polyester (un heat shrunk).
    I think I have some as scrap - send me an address and I'll ship it to you.
    For your next level test. :D:D

    How long is the model?

    OOps, I just saw you are in England.
    I'd probably send it anyway.
     
  3. alan craig
    Joined: Jul 2012
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    alan craig Senior Member

    Thanks upchurchmr. 34" x 10". I've still got enough polyester left over from a 14ft skin on frame boat Skin on teak boat https://www.boatdesign.net/threads/skin-on-teak-boat.61282/ to do a small canoe. Although tee shirt fabric is too stretchy to add any strength to the structure i'm hoping it will be stiff enough after painting to be viable. It's so easy to cover as it stretches on with only a single cut at the stern. I've just given it the first coat of paint and it's very slow drying (especially in a wet November) so it will be a few days before I report back.
    p.s. Very nice strip plank boat in your profile!
     
  4. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    I assume then you don't need more. Tell me if I'm wrong.
    I made the assumption that you had no experience with actual SOF skinning.
    Sorry.
     
  5. alan craig
    Joined: Jul 2012
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    alan craig Senior Member

    No I don't need any more fabric, and thanks very much for the kind offer. Don't be sorry; I feel like I've upset you!
     
  6. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    Not upset at all. I've tried pushing my scraps on others, mostly because I assumed a lack of experience. And I'm not planning SOF again, but I save everything.

    That really reflects on myself.

    Good luck.
     
  7. Barry
    Joined: Mar 2002
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    Barry Senior Member

    Older fabric airplanes used a material called Ceconite, this might be a trade name.
    A family friend used to fly spotter flights for water bombers with a supercub and this the fabric the plane was wrapped with.
    You can glue the edges and then iron the fabric and it tightens up like a drum. Then coat it with a paint and you have a waterproof membrane
    50 years ago, in the days of no money, my friends and I built 18 - 20 foot kayaks and they worked fine. We just put a thin coat of resin over the ceconite
    You can google something like " applying fabric to airframes" to find threads on the application.
     
  8. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    Ceconite is a trade name for Polyester fabric, in lighter weights than normally used for boats.
    But as Barry said, it can be used for lighter boats.
    Even aircraft don't use resin for a coating.
     
  9. alan craig
    Joined: Jul 2012
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    alan craig Senior Member

    I'ved used a tee shirt because that's what I wanted to try; I'm aware of the coverings for fabric airframes.
    Picture here of the hull with two coats of wood primer (I'm only using the old paints that are filling up my garage). I've now added two undercoats and the weave still isn't completely filled (Hammerite garage door paint!), next is gloss from a local DIY shop.
    I think I knew when I started that this wouldn't be viable for a full size boat, but if it doesn't leak in the bath test I will probably carry on and make it radio controlled.
     

  10. alan craig
    Joined: Jul 2012
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    Location: s.e. england

    alan craig Senior Member

    My last post here was a while ago. I couldn't decide wether to bin the model or carry on making it into a radio controlled model. Finally decided to continue so I will document it here.
    It floated fine in the bath without leaks and the sash weight I had lying around immersed it to a sensible waterline so I decided to carry on. No plans, just keep going. Slowly. So the boat now has a keel (awaiting paint and a sealing gasket), a cambered deck, rudder and cabins. and an aluminium mast. Next step is a few more spars, a gaff cutter rig and standing rigging.
    Model yacht on work/carry stand. Ballast just fits inside stand.
    Even a toy needs a cambered deck and a nice sheer line.
     
    Dejay and BlueBell like this.
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