Primitive Archer
Main Discussion Area => Bows => Topic started by: DC on June 26, 2018, 12:03:58 pm
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This is a test bend on a piece of scrap Douglas Maple with the opposite of the usual cracking on the outside. The wood crushed on the inside. A first for me. I used steam and a strap. It's 1 3/4" radius. Is there something I could have done or not done to avoid this?
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Maybe a gentler radius.
It's fixable by rasping it down thinner and the bending a tin piece of maple and gluing it on.
In fact that possibly a good way to do very tight hooks, make 'em thin so the will take the band and then glue on a pre-bent thinner patch.
I've used this trick on the belly.
https://bowyersdiary.blogspot.com/2013/05/radical-recurve.html (https://bowyersdiary.blogspot.com/2013/05/radical-recurve.html)
Del
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I've had this happen with thick yew sapwood. I just scraped it down till it couldn't be seen. If your curve is thick enough afterwords, you're good to go. The other time I did it, I did what dell said, glue on a lam, if its too thin.
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I had it with yew and a tight radius too. Cut the radius of the form a little bigger and shortened the bow a bit. Bigger bend went fine, just tillered it to brace today actually
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It was just under 1/2" thick. I tried another, same thickness, but I loosened the strap a bit. It wrinkled the inside and lifted a splinter on the outside. I made one 3/8" thick. it's cooling now.
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That happens DC on many different types of wood over here too DC.Does'nt affect anything negatively really though after heat tempering.
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It could be partly due to the type of maple, and whether it was air dried or kiln dried.
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It's air dried.
I kerfed one that is a half inch thick and bent it over the same form. Look at how much difference there is in length. It's no wonder it splinters and crushes. If it was not kerfed it would have to stretch and/or compress 1/2" in six inches.
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Good demonstration DC.Now you can just glue that kerf together and then there's no need for tempering with a heat gun...but you have that glue yet though.
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I like the kerfing method for that reason. Once it's glued it's there forever. I like to put my recurves in early and I never seem to get the kerf centered.
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I use that same kerf method with laminate bows and recurves. Just slide in a matching curved piece and you can’t even tell it’s there.
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I wish my glue lines were that good. I have to use contrasting colour wood to hide them. :)
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@ DC
That photo showing the movement when done with kerf is great :)
Easily worth a thousand words.
Del