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Main Boards => The Bowyer's Bench => Topic started by: tim roberts on February 27, 2009, 09:34:00 PM
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What kind of heat is needed out of a heat gun for bending limbs? I looked at one today that had a 300-500 degree range, is this enough or does it need to throw more heat?
Thanks,
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I have a 1000 and it is barely enough.
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You are going to need more than that. Mine is a $30 Milwaukee heat gun that has lasted me 10 years so far. It's high temp is 1000.
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At that high of tempurature, how does one keep from scorching or burning the stave? Does the stave get that hot?
Thanks again,
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My heat gun is an old B&D I bought for $5 at a garage sale years ago. It is rated at 1200watts and has a 2 position switch. I use it on #2(high) mostly.
When I am bending wood with heat I use oil on the area to be bent, straightened or recurved. When the wood is too hot to touch usually it will bend, osage especially. By using oil the wood doesn't scorch. Keep the heat gun moving too.
When tempering belly wood I don't use oil but scorch the wood to a chocolate brown.
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I gave my heat gun away.
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Can you please explain "tempering belly wood", how and why?
Thanks again,
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Tempering a bows belly is done to increase the compression strength, mostly with whitewoods but it also works on osage, locust and other heartwood bows. Marc St Louis popularized it's use and wrote a chapter in TBBIV and an article is a past Primitive Archer magazine about heat treating (tempering) belly wood.
The way I do it is put the bow in a form, belly up and begin to heat the wood at the fades. I use a heat gun for this. When the wood begins to scorch I slowly move out the limb a bit at a time until I get near the tips. I want the scorched wood to be chocolate brown.
After scorching I leave the bow in the form for probably 4 or 5 days to rehydrate. If the R/H is low, you will want to wait longer. The tempering makes the wood very dry and brittle and if you stress it too soon, it will blow!
I have removed slight set and increased weight 5# to 6# with tempering. You want to temper only dry wood or you can cause checking.
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Heat treating a belly - that would be after tillering? Thanks
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Generally but not necessarily after tillering.
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Tim, don't bother dinking around with tempering the belly of your bow until you get a few bows under your belt. Also, the humidity where you live, like where I live, may not allow the wood to rehydrate enough to prevent blowing up. Unlike those in the mid west and east, our problem with bow wood is to little wood moisture not too much.
Quit worrying about making the perfect bow your first attempt and start making some shavings. Next time you post, I want to see some pictures of the stave (in a reduced state) you are working on.
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Excellent advise, Walt. I live in the South East US and "TOO DRY" is rarely a consideration. In your neck of the woods hickory is superior to most other bow woods because of the dryness and 6% hickory will stand it's ground with any other bow wood.
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Ok Walt, should have my work bench done, or to a point I can start using it by next Monday, with that said, I will have some pictures to post next week.
Thanks for all your help guys!!! :D