Dry-Bent Laminated Stem Springback?

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garypete
Posts: 34
Joined: Tue Feb 22, 2005 7:32 am
Location: Rice Lake, WI

Dry-Bent Laminated Stem Springback?

Post by garypete »

I just glued up a dry-bent laminated stem for a Prospector using Titebond III. I'm wondering how much springback I'll see when it comes off the form. The three 1/4" laminations (1 white ash and 2 white cedar) were dry bent using a heat gun sparingly at the tightest part of the curve. It went so easily that I may switch away from steam bending stems in the future, even though I love the smell of steaming white cedar in my shop.

Any experienced dry benders out there? Or do we all use steam?

Gary
When people figure out what's really important in Life, there's gonna be a big shortage of canoes.
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Glen Smith
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Joined: Sat May 08, 2004 9:08 am
Location: Baie-St-Paul, Quebec, Canada

Post by Glen Smith »

There have been varying reports of springback on dry-bent and steam-bent stems. The important thing is to tie the ends together like a bow when you remove them from the mold otherwise they might open up even more before you get to use them. If you have to use force to get them back on the stem mold, they have sprung-back too much. I have had some dry-bent stems spring back about 2" but it was very easy to push them back into shape with just finger pressure. My normal spring-back is about 1/4" to 1/2".
Snowman
Posts: 233
Joined: Tue Jan 25, 2005 6:21 pm
Location: Gatineau, QC

Dry-Bent Laminated Stem Springback

Post by Snowman »

I have only used the dry heat gun method. It worked extremely well, with only a minor hint of a problem in the tightest radius on the inner stem (at the stern on an Endeavour), using 1/4" cedar. Some of the outer fibers showed slight signs of failure, but not significant enough to abort the lamination (none of the areas were coincidental and were so small that you had to be told about them to see them. I might consider a pre-bend moisurizing step, or go with a five layer laminate (as opposed to 4 layer, 1/4").

The outer stems (1/4" ash) gave no probllems at all. I got very minimal springback without tying the ends. Similar to Glen, I got 1/4" to 1/2" springback that only required slight finger pressure to properly place.
Snowman back East
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