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PostPosted: Mon May 01, 2017 2:36 pm 
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Location: Albuquerque, NM USA
A friend was making a rim for a serving tray and gluing up a bunch of thin laminates in a form. When it came out of the form there
was a small bit of spring back but in the next several days it "went the other way" by a lot. Does any one know why and how to
either anticipate or prevent it. ????
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Thanks.
...lew...


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PostPosted: Tue May 02, 2017 6:17 pm 
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I've done lots of bent laminations and this has *never* happened to me. The piece has a lot of machining on the inside of the bend, which I assume was done after it was bent and glued. I wonder if that might have something to do with it, not that it would make much sense, either.


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PostPosted: Tue May 02, 2017 6:26 pm 
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Yeah, I'm with DR ... I've never had any glue-up bent lams behave that way. For more clues, what species of wood, what glue and were the lams bent dry or steamed?

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PostPosted: Tue May 02, 2017 7:45 pm 
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Hey Guys,

I quite certain that the milling/shaping post lamination is what caused the walk back. If you think about it, the lams on the inside of the curve are under compression and the outside under tension, just like if they were steam bent. Once you remove wood from the inside, there is less to resist the compression and the piece walks into the curve.

My 2ยข,
Tom

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PostPosted: Wed May 03, 2017 7:09 am 
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Tom, I'll have to check with him (today if I can remember) on if the machining had been done before or after the "spring back".
But that does sound like a likely suspect. I do know the glue was Titebond III not too sure of the wood.
Thanks.
...lew...


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