first go at steam bending (on a tiny scale)

Discussion in 'Wooden Boat Building and Restoration' started by Tiny Turnip, Dec 15, 2017.

  1. Tiny Turnip
    Joined: Mar 2008
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    Tiny Turnip Senior Member

    I've wanted to have a go at steam bending for a while and the need arose with a model project. I'm putting mahogany gunnels on a 13 inch fibre glass clinker row boat hull. the section is 3mm x 3mm. i saw a YouTube recommending using a baking dish full of boiling water as an easy way for small scale stuff, rather than making a steaming oven, so I tried it. I boiled the sections for 40 minutes and then clamped them round the gunnels and left them to cool and dry. they took the curve when hot (and I'm pretty sure they would have snapped prior to heating ) but when cool I removed the clamps and the timber sprang back straight. I was expecting them to have set in the curve they were bent to. any pointers as to what's gone wrong? thanks. 20171215_183813.jpg 20171215_183800.jpg
     
    Last edited: Dec 15, 2017
  2. jorgepease
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    jorgepease Senior Member

    some spring back is going to happen, the longer it stays bent, the more it wants to stay that way but if you want it to hold, say the shape of the gunnels, then you have to over bend it.
     
  3. Tiny Turnip
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    Tiny Turnip Senior Member

    thanks - yes it seems to be getting better. I'm probably being a bit impatient!
     
  4. waikikin
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    waikikin Senior Member

    Hi TT,
    never done it myself but have spoken to a couple people that in model making use an ammonia solution, apparently on small stuff you can "tie knots in it...
    Jeff.
     
  5. messabout
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    messabout Senior Member

    Ammonia is unpleasant to work with but it does do the job of making wood bendable. Do it out doors. Maybe not tying in knots but plenty flexible for curves such as the model sheer clamp. Some woods are more easily bent than others. I have never tried mahogany or teak. The pictures suggest that may be one of the types being persuaded.
     
  6. PAR
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    PAR Yacht Designer/Builder

    There's a huge difference in bending small, thin stock and bigger stuff. Small stuff can be bent with just a heat gun and a squirt bottle of water or alcohol, but bending larger stuff, say, real boat size, well this is quite different. You may learn a little from this model bending thing, but the real lessons will be had with full size stock, usually after it snaps in mid-bend.
     

  7. Tiny Turnip
    Joined: Mar 2008
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    Tiny Turnip Senior Member

    Thanks all for the helpful comments. The gunnels have settled to a point where I can work with them. I suspect the mahogany was kiln dried.
     
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