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Main Boards => The Bowyer's Bench => Topic started by: ranger 3 on March 22, 2009, 08:49:00 AM
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A friend of mine just finished a bow and left some sap wood on it. Well after shooting it in there is a crack in the sap running straight across about 10" above the handle (it is a bendy handle)is is fire wood?
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I've never none this but I know someone that did.And this happen to them also.It's a stress crack.Osage sap wood has no tention,not a backing.You can srape it off and it will be ok.
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I have done this quite a few times with no problems. I have made osage bows that are all sapwood, bows that are 50/50 sap/heart wood(60" static recurve) and heartwood osage bows with a ring or 2 left on as the back.
If you know the sapwood is sound, it can be used on a bow. If you receive or buy a stave from someone else you can't be sure how the wood was handled after harvest. Most folks don't consider the sapwood of osage to be a viable bow wood so they don't treat it in a way to allow it to be, but in my experience it can be. On some of the bows I've built with sapwood left on them I added a rawhide backing for insurance.
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I've left sapwood on black locust and on an osage sucker but I don't do it unless there is not enough heartwood. The closer the sapwood is to the heartwood the denser it is. If I can I take it off for those woods. Jawge
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I know Dean Torges mentioned that you can use sapwood on the back IF the bow is forced dried in a hotbox, but I don't like sapwood on the back of an osage bow.
Sapwood is just too hit and miss. It dries at different rates that the heartwood and the it winds up splitting the back of a bow.
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If a stave is totally dried with the bark and sapwood on and you know the sapwood is sound; without bugs, fungi, etc, the sapwood of osage is as strong or stronger than many whitewoods.
In the last few years, conventional wisdom regarding bow woods and construction methods has changed and in some cases dramatically. On the osage bows I have built that I used sapwood either as the entire bow or a portion of the bow I never had a problem with the sapwood. I was sure it was in good condition but I never had a problem.
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Think of osage sapwood as a whitewood. Your treatment needs to be different than with osage heartwood. If you immediately debark after cutting and then get a stave down to near bow dimensions, and coat liberally with shellac, it will do just fine. Like all wood, some is good, some is bad but it's still wood. Design for the wood.
Sapwood rots quickly when exposed to the elements. Much like even the best of whitewoods if left on the ground.
Sapwood checks mercilessly if you allow it to loose its moisture too fast.
I have a half-sapwood bow I am woring on right now. Maybe I'll take some pics as I work on it.
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Back to your crack it developed because of stress.When you tillered it a little to much at this spot and after shooting it.After a while a your bow showed where thr stress in your limb is.
Sap wood dose rot quicky.So unless your the one that took off the bark and you know it's not roten I would'nt try it.
Other than protecting your back ring.It really worth it.I've never done it.