Steaming Wood - How long?

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fanglyfish
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Steaming Wood - How long?

Post by fanglyfish »

Hi Guys,

I am bending the wood for the stems on my first canoe this weekend. How long should i have to steam the wood before it will be plyable enough to bend?

Also, what kind of glue should i use to laminate the strips together?

Thanks,
Matt
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mtpocket
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Post by mtpocket »

I steam 15 minutes for every 1/4" of thickness. If your laminations are 1/4" thick each, 15 minutes should do just fine.

I use thickened epoxy for glueing laminations together. Wood glue probably works just as well. Make sure the wood is dry before applying epoxy.
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Erik, Belgium
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Post by Erik, Belgium »

The size of the steambox or pipe is an important factor.

some more info about steambending on the web:
http://www.danenbergboatworks.com/steam_bending.htm
http://www.faqs.org/faqs/woodworking/wood-bend/

Erik, Belgium
stovetop
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Post by stovetop »

I just did mine not too long ago and I used a 4.5' piece of Sch. 80 PVC pipe with a cap at one end and rags stuffed around the teapot at the other end.
I steamed 7 strips (6 ash, 1 cedar (to protect the ash from clamp marks)) and found that 15 minutes once she was up to full steam (pardon the pun) to be plenty of time. The strips were 1/4" x 7x8" x 4'.
I also found that I had plenty of time to do the bends in the 45 seconds stated in "Canoecfaft" I went with clamps every 3rd clamping hole (my forms have 17 holes) and everything came out great. Just make sure they are good and dry before glueing them up.
Mark
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Michel vd Hoven
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Post by Michel vd Hoven »

I would recommend to soak the wood in water for a night before steam bending.
My cherry stems were steamed for 20 minutes. Without the overnight soak in water it cracked - with one night soak it went just fine.

Michel, The Netherlands
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ealger
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Soaking Stem Material

Post by ealger »

Soaking wood before steaming presents a problem. If the pieces are not quarter sawn, soaking can cause the material to swell more on one edge than the other. If this is the case, the pieces can be turned end for end to try and compensate.

This is one of the reasons I like to cut my stem pieces to .150" ( 5 x .150 = 3/4") and bend them without steaming. This can be done for the Prospector. For some other designs with large recurves is another matter.
Ed...
Ed Alger
fanglyfish
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One more Question

Post by fanglyfish »

How long do I have to get the wood from the steam box and bend it to form on the stem mold? I am hearing anywhere between 45 seconds to 15 minutes...
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Glen Smith
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Post by Glen Smith »

You have to be fast. I find that it takes a few seconds of applying hand pressure to the strips before they actually start to give and take the bend. Then I go quickly to complete the bend and get a few clamps on to determine the final shape. This takes me from 45 to 60 seconds. Then I add the rest of the clamps. I always prepare all of my clamps beforehand by adjusting them to the gap I need so they are ready to go to work. It is also a good idea to have one extra lamination on the outside of the stack to take the bending tension and absorb the clamp pressure. This also helps reduce the risk of splitting laminations. Usually after 1 or 2 minutes the strips have cooled to the point that they won't take any more bend without breaking or cracking.

Since I always work alone, one of my procedures is to steam and bend the inner stems only. Then I will allow them to dry overnight and glue them together the following day. I allow these to set overnight and the following day I steam and bend the outer stems over top of the inner stems. Again, I allow to dry overnight and glue them together the following day making sure I don't glue the outers to the inners.
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