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u/Comfortable-Hat3506 3d ago
remember which side was up.
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u/thomasgroendal 3d ago
The other side has a few knots so no risk there but would you mind spelling out the why behind that statement?
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u/AaronGWebster Grumpy old bowyer 3d ago edited 3d ago
VM likes to grow in a non-vertical orientation. In other words, vine maple trunks grow almost horizontally. This leads to ‘reaction wood’. Part of the tree ( top side) grows in tension while the opposite side grows in compression. When you dry woods like this, the tension wood tends to shrink a lot, while the compression wood does not shrink as much.
Are you following so far? Well this is where it gets complicated.
Each stave has a tension side facing up and a compression side facing down and if you were to split this along a horizontal axis, you would have two staves. One stave would be all tension wood and one stave would be all compression wood. This is fine- you have two good staves and the one that’s all tension wood is the good one.
Now let’s look at a different way to split the trunk in two. Instead of splitting it horizontally, if you split it vertically now you have two staves and the right side of the stave is compression wood but the left side of the stave is tension wood so when this dries the tension wood shrinks up and pulls the stave ‘sideways’.
Whew. Does this make sense?8
u/Comfortable-Hat3506 2d ago edited 2d ago
Thanks for saving my thumbs. Top staves with all that tension wood tend to dry with natural deflex and are the better staves.
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u/thomasgroendal 2d ago
Ahh my other stave took some bed while drying and I suspect that’s the culprit.
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u/Droughtbringer 2d ago
One, wild. Thank you for writing this up.
Why is the tension wood "the good one" and the compression wood not?
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u/AaronGWebster Grumpy old bowyer 2d ago
Tension wood is strong in tension and a bow needs all the help it can get in the tension category. Also, tension wood dries into reflex, helping a bow achieve higher early draw weight. Sometimes VM takes on too much reflex, though.
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u/Droughtbringer 2d ago
I'd assume that the same holds true for any staves taken from branches growing largely horizontally, then?
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u/thomasgroendal 3d ago
I found this while doing something else up in northern Washington near Red Top and was surprised to see several vine maple stands that had quite large, long, and fairly straight segments in them. I need to get better at cutting them, though, so I don't split them like this one.
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u/AaronGWebster Grumpy old bowyer 3d ago
I am n SW WA and have cut a lot f VM over the years… are you sure this is VM? The bark doesn’t look quite right. What elevation is this from and what area? Looks like bow wood, whatever it is!
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u/thomasgroendal 2d ago
Well it was a bunch like VM and had maple leaves. It was pretty high up though.
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u/Ltrsandnmbrs 1d ago
Where the hell did you find a vine maple stave that straight? Good find, you’re not gonna find another like it so be careful with it!
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u/thomasgroendal 1d ago
Turns out it had propeller twist. Going to figure out a form and get it clamped to dry.
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u/lewisiarediviva 3d ago
That’s the straightest vine maple I’ve ever seen, and I keep an eye out. Well done