Wood Bending with Ammonia

Discussion in 'Boatbuilding' started by dklavdianos, May 23, 2018.

  1. dklavdianos
    Joined: May 2016
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    Location: Greece

    dklavdianos Junior Member

    Hi everyone,
    I need to bend strips of sapele mahogany (L 1m x W 45mm x T 6mm) and the method of ammonia seems to be the most plausible one due to the small number of equipment need in contrary with steam bending. The configuration I'm thinking of , consists of a PVC tube capped in both ends, filled with ammonia (or ammonia mixture) with the mahogany strips in.

    I've read that you can soak the wood in ammonia and let it do its work, however I'm not familiar with the time needed or if the ammonia needs to be mixed with water or something...

    Is anyone familiar with the method? Are there any tips and tricks which might be handy?

    Thank you in advance.
     
  2. dklavdianos
    Joined: May 2016
    Posts: 2
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    Location: Greece

    dklavdianos Junior Member

    Actually the more I read the more I hesitate... it seems to be kinda dangerous...
     
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Sapele doesn't like to bend much, so expect some breakage, likely in the 50% range if you have many to do.

    Alcohol and ammonia will help with the bending process, except for the explosive hazard, which is quite daunting. I wouldn't recommend anyone that has limited experence bending with these chemicals remotely try it. Both alcohol and ammonia are best used as a soak, rather then heated.

    In the end, it all depends on how much Sapele you need to bend and the radius's you need to conform to. Tight turns will break Sapele readily, though can be done with well selected stock and backers to support the material during the bend. Grain run out, how "green" the stock is and grain orientation, will be things you'll constantly have to manage. Some of the pieces you bend, you'll look at it and just know it's not going to make it, but you'll try anyway and sure enough it'll break, usually about where you figured it might.
     
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