Overbuilt bows

[PatM]

  That may come down to whether the natural "laminations"  slip a bit when lignin plasticises  with heat.

 It seems like dried in reflex is more like the shrinkage of sinew where the elastic nature of the material  causes it to shorten with drying.

 Certainly if you bend a stave  the proper way a few inches the stave bounces right back so it's hard to imagine a compressed back holding like set  after only being bent to such a small degree also.

[George Tsoukalas]

Comstock in The Bent Stick seemed to feel over built bows performed better than those that were not.
Jawge

[Badger]

Comstock in The Bent Stick seemed to feel over built bows performed better than those that were not.
Jawge

  Pat, that is not what I said, I said if a compressed back pulls back out to some degree is doesn't act like set where the belly is getting crushed. The belly crushing creates more hysteresis and when a back pulls out you just loose some reflex.

[PatM]

  I wasn't comparing it to the effects of belly set.  I was arguing that it likely can't be any sort of compressive "set" in the back at all but rather temporary shortening that gets stretched back out to a degree.

[Badger]

  I think that is the same thing that I was saying. When the temporary shortening comes out it looks like set

[PatM]

I would agree with that.   A  straight grown tree usually attains reflex when split and dried but it may be better to keep in mind that the shape it was in before splitting  and drying is more representative of its true shape.

[bradsmith2010]

I was watching video of horn bow, the guy cut horizontal slots in the core wood,, from this discussion,, I am assuming it was to prevent the wood from being compressed on the back, so the sinew could pull it into reflex without as much resistance,,?

[PatM]

I was watching video of horn bow, the guy cut horizontal slots in the core wood,, from this discussion,, I am assuming it was to prevent the wood from being compressed on the back, so the sinew could pull it into reflex without as much resistance,,?

 Which video?

[bradsmith2010]

I think it was the same one Marc posted

XIAOSHAO BOW | ZWE   its on utube,, nearly has 3 million views

[PatM]

I think that was more to establish the curve there.  You will note that he bends the bow in that spot and glues on a piece that acts like a form.  Then after the belly is glued on to set that curve he removes the form chunk and the notched areas completely before sinewing.

[bradsmith2010]

ok cool,,I love that video

[willie]

  That may come down to whether the natural "laminations"  slip a bit when lignin plasticises  with heat.

 It seems like dried in reflex is more like the shrinkage of sinew where the elastic nature of the material  causes it to shorten with drying.

 Certainly if you bend a stave  the proper way a few inches the stave bounces right back so it's hard to imagine a compressed back holding like set  after only being bent to such a small degree also.

couldn't the cause of dried in reflex be that the recently living and wetter sapwood hasn't undergone as much shrinkage as the older wood towards the heart?



Steve,
I think there is more to be understood about the different kinds of set. On thing I have noticed is that conifer wood seems to recover differently than hardwood. probably something to do with microfibril angles. Just guessing, but there is probably even a variety of ways  a specific hardwood can differ from one tree to the next, or even from one part of the tree to another. Primitive accounts often show bowyers putting much value on just what part of a tree to get the stave from. I like to harvest my own staves for this reason, but still have a lot to learn about just what makes for a better bow.

[PatM]

  That may come down to whether the natural "laminations"  slip a bit when lignin plasticises  with heat.

 It seems like dried in reflex is more like the shrinkage of sinew where the elastic nature of the material  causes it to shorten with drying.

 Certainly if you bend a stave  the proper way a few inches the stave bounces right back so it's hard to imagine a compressed back holding like set  after only being bent to such a small degree also.

couldn't the cause of dried in reflex be that the recently living and wetter sapwood hasn't undergone as much shrinkage as the older wood towards the heart?



Steve,
I think there is more to be understood about the different kinds of set. On thing I have noticed is that conifer wood seems to recover differently than hardwood. probably something to do with microfibril angles. Just guessing, but there is probably even a variety of ways  a specific hardwood can differ from one tree to the next, or even from one part of the tree to another. Primitive accounts often show bowyers putting much value on just what part of a tree to get the stave from. I like to harvest my own staves for this reason, but still have a lot to learn about just what makes for a better bow.

   I doubt the inner wood has shrunk much  if it's still wet.  Likely a function of more total surface area able to shrink in both length and width that wins that battle.  Even with the bark on.

[Selfbowman]

Yes this is good info once more. Thanks. I am not sure I am ready to give my two cents just yet . I don't understand all the terms being used but maybe the theory.  Arvin

[rps3]

I definitely lean toward overbuilt, hopefully overall, and not just in one spot. I see it as the less overbuilt, the closer I am to the bow breaking, and how close to that line do you want to dance. I make bows to hunt with and give away, so I mostly want durability. But who doesn't want performance?...maybe Ill get a little closer to that line.

When I first started out, I thought my lack of set was due to my skill in tillering, but soon realized it was that I was overbuilding the bows a good bit.