Author Topic: First heat treated bow  (Read 1405 times)

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Black Moshannon

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First heat treated bow
« on: January 31, 2020, 11:23:24 am »
I finished my first heat treated bow. Its hickory, 67" long and 1 1/8" wide. It pulled 65 pounds at 27" when I first finished tillering, I expect it will have dropped a few pounds. I was going for a 60 pounder. I first dried it and removed some of the deflex with heat and lard, as the stave had about an inch of deflex to start.  I tillered it to 60 pounds at 24". At that time it had about a half inch of string follow. I then reverse braced it. I propped it over an old charcoal grill about 12" from a bed of charcoal and gave it an hours toasting which made the belly a medium brown. I waited a couple days and started tillering again. I finished tillering to 27" and the bow now has an inch of string follow. The bow has a flat belly and crowned back, it was made from a small diameter tree. I finished it with tung oil.

I made a linen string for it and shot it, it seems to shoot great. Only problem is, right in the back at the arrow pass, there's a small spot where a tiny lateral crack seemed to be. It appears there is a small knot there. The back was simply the wood directly under the bark so no ring chasing was done at all. The tiny crack appears to be the edge of a growth ring where it meets the knot. The crack followed up the growth ring in a splinter-like way. I did a small amount of scraping and sanding to the area which took the edges of the crack away, making it disappear. Again, it was very tiny to begin with. There is still a small dark spot on the edge of the knot where the edge of the crack was. I braced it back about 18" and applied some wood glue, then relaxed the bow, just in case there was any separation still there, so the glue could get in. Hopefully all will be well now.

Overall I was pretty happy with taking a stave with 1" of deflex to begin with, and ending up with a 65# bow with 1" of string follow. I am not used to seeing any back problems on my bows and wonder if this little cracked area was due to the stress on the back from the belly being toasted. The bow has an even tiller so that shouldn't be the issue. Anyways, I call it a success and my next bow, an elm stave, will be heat treated too.

Offline Hawkdancer

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Re: First heat treated bow
« Reply #1 on: January 31, 2020, 11:30:26 am »
Post some pics!  Hope it holds up well, hickory is pretty tough wood!
Hawkdancer
Life is far too serious to be taken that way!
Jerry

Offline artcher1

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Re: First heat treated bow
« Reply #2 on: January 31, 2020, 11:52:17 am »
Sounds like, where knots are hard and dense, and the growth rings less so, the wood around the knot shrunk and contracted from the heat causing that lateral crack. Pictures would really help..….Art

Offline scp

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Re: First heat treated bow
« Reply #3 on: January 31, 2020, 04:51:18 pm »
I would not be bending and tillering a bow just two days after toasting it for an hour, especially if it has crowned back and flat belly. I would be weighing it everyday to see if its weight is changing at all.

Black Moshannon

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Re: First heat treated bow
« Reply #4 on: January 31, 2020, 05:20:31 pm »
That's probably what I should have done. I guess it was more like three days when I actually started work, I strung it before that. I heard hickory was especially tough in this regard, and this piece really climbed in MC when out of the drying box for only a few hours. It seems I didn't leave enough of a raised protected area around the knot, even though I really didn't work the back other than a slight filing and sanding to get the inner bark off. I may have accidentally filed that spot. I'll try to get some photos on here.

Offline RyanY

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Re: First heat treated bow
« Reply #5 on: January 31, 2020, 05:27:34 pm »
1 1/8” wide seems very narrow for a hickory bow at that weight. Does it bend through the handle? Can we see some pics?

Black Moshannon

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Re: First heat treated bow
« Reply #6 on: February 01, 2020, 12:43:17 pm »
Here are some photos, of the crack, the bow at full draw, the strung bow, and the toasted belly. It is a bend through the handle.

Black Moshannon

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Re: First heat treated bow
« Reply #7 on: February 17, 2020, 10:34:14 am »
After around 300 shots and probably 100 pulls to full draw it’s still holding up. Still that spot makes me uncomfortable. The elm bow I’m working on should be a big improvement.

Offline aznboi3644

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Re: First heat treated bow
« Reply #8 on: February 17, 2020, 02:50:11 pm »
Looks good to me. I would wrap the crack with sinew and glue and just keep shooting.

Black Moshannon

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Re: First heat treated bow
« Reply #9 on: February 17, 2020, 06:16:56 pm »
That's a good idea..I'll put a leather handle over the sinewed spot. I hate putting handles on bows because I think they look ridiculous and serve no purpose but its better that the ugly wrapped spot. Oh well i'll take what I can get and try for better.