Steaming Mahogany

Discussion in 'Wooden Boat Building and Restoration' started by lewisboats, Apr 1, 2010.

  1. lewisboats
    Joined: Oct 2002
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    lewisboats Obsessed Member

    How well does Mahogany steam bend...and don't ask what kind...I don't know. It is Menard's mahogany trim...1 1/4" x 1/4" thick. The stuff has too much tension in it and is distorting the shape of my shear so I need to steam it or soak in hot water or something to get it to bend easier so I can get a preset bend in it. I'll post a pic of it manana as I am just about to go out the door.

    Steve
     
  2. alan white
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    alan white Senior Member

    That thickness should be easy to steam bend, and in only a few minutes in the box. You probably have got a bit of edge-set causing the distortion. The trick is to soak the wood through and through (in water for a few hours) prior to steaming, due to the wood probably being kiln-dried.
    Good luck.
     
  3. lewisboats
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    lewisboats Obsessed Member

    Good to hear...but I have too curvy a shear and the ply is only 3mm so the stiffness of the Mahog is actually straightening it out (in plan view) from what I want. I'll pick up a PVC pipe and a couple of caps tomorrow so I can soak and steam them. Would boiling water in the pipe work after soaking?
     
  4. alan white
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    alan white Senior Member

    I'd say it would be a similar result. I've boiled and steamed with good results.
    Otherwise, it may be necessary to rip the piece in half, like 9/16" wide each and join them during assembly.
     
  5. lewisboats
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    lewisboats Obsessed Member

    OK...here is the pictorial skinny.

    This is the wood I want to bend.

    [​IMG]

    [​IMG]

    [​IMG]

    And this is what it needs to bend to...without distorting the shape that you see here. Dry it wants to flatten out the curves. The sides are only 3 mm ply so the solid wood is twice the thickness of the base ply

    [​IMG]

    [​IMG]

    So far I am leaning towards getting a long piece of PVC pipe, some caps and then fill with wood and water to let soak then fill with boiling water for a while before trying to bend it. I will make a form to bend it to that has a bit more curve to it than the boat sides so as to allow for some spring back. It doesn't have to be exact...just so it doesn't have so much tension in it that it straightens the curves out. I will hopefully be using the darker ones (left and closeup) for the outside and two of the lighter ones on the inside. My last resort would be to thickness plane it down to 1/8" and laminate...but I can't get all the same color so it would be funky (er) looking.

    Steve
     
  6. gonzo
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    gonzo Senior Member

    That is not mahogany. It is lauan or whatever commercial name they gave it. That species steams bend characteristic is mediocre.
     
  7. alan white
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    alan white Senior Member

    Yeah, looks like luan, which is technically a cedar (may be spanish cedar too). Those cedars have a lot of variation within the species, light/dark, hard/soft. Anyway, your plan sounds good.
     
  8. lewisboats
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    lewisboats Obsessed Member

    Test Successful! I soaked for about 36 hrs but it didn't do a whole lot. Soaked in hot water for an hour or so and voila...much more limber. I'll let it dry and see how much of a set it will take. Even if it springs back 50%...that should be just about right for what I need.

    [​IMG]

    [​IMG]
     
  9. alan white
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    alan white Senior Member

    Steve, why can't you simply clamp the outwale to the boat until dry? That's what I do. You know it will take the bend later even if you get some spring-back.
    What I meant before was if you soak the wood for a day or two it makes steaming or boiling much more effective. It does get a bit more limber from soaking alone, but not enough to take a big bend.
     
  10. dskira

    dskira Previous Member

    I always wounder about lauan. Used primaraly for plywood, and I find that in wood finder:

    DESCRIPTION: The lauan genus (Shorea) contains about 70 species and their woods are extremely variable. Some are as soft as basswood while others are harder than white oak. Color may also vary from ash gray to dark reddish brown. The lumber industry markets these woods by their appearance and density characteristics rather than by species. The denser, dark red merantis have better decay resistance and are relatively stable. Most of the lauans are coarse textured and have poor decay resistance. Some have high silica content and may dull cutters, while others are exceptionally gummy. Lauan is widely sold around the world as "Philippine mahogany", including its use for plywood face veneers. It is one of the world's most popular timbers.

    Daniel
     
  11. lewisboats
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    lewisboats Obsessed Member

    Oh...this worked FANTASTIC...it was actually a bit more curved than needed but straightened out to exactly what I needed with just a little finger pressure...and stayed that way. There should be no adverse tension on the ply at all but gluing them all together should cement in the shape and make it stiff.
     

  12. lewisboats
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    lewisboats Obsessed Member

    Got the real thing soaking now...hopefully I don't do something to screw it up. The two nicest and darkest pieces are the ones I want to use for the outwales. For any further updates...see the " While the snow flies" thread...

    This one has served it's purpose so time for the archives.

    Steve
     
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