Primitive Archer
Main Discussion Area => Bows => Topic started by: Razorback on September 05, 2013, 09:20:41 am
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Ok. I am working on a hickory pyramid bow. It is a belly split with a mix of late and early wood. I am going to back it with .200 hickory slat. Roughly how thick do you think the limbs should be for 55# bow before backing and at what stage should I temper the belly to improve its compression abilities. i have never tempered a bow for this before.
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Be careful when tempering hickory. The wood needs to be thoroughly dry, or it will warp when you temper it. You'll want to temper before you back it, I imagine.
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Yep I've tempered a bunch of hickory[it gets along well with it]and that should be done before your lamination is applied.Never did a belly split though.Imagine you have some heartwood on this.I think that stuff can get a little more brittle.
Limb thickness will depend a bit on your length and how wide your starting too.Maybe a picture and dimensions would help..200 thickness for a backing is plenty thick.That's over 1/8" thick.I think you could go thinner than that but don't know your core thickness at the moment.
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Yes there is heartwood, which I am hoping to keep for the contrast. The bow is 66" ntn and 2" wide at the fades tapering to 1/2" nocks. It is 68" ttt so I can go a little longer if needed. The stave is currently a little more than 1/2" thick at its thinnest so will be close to 3/4" thick, which should be plenty for 55#.
How hot should I get the belly for appropriate tempering.
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get the bow bending slightly more than floor tillered, heat treat it (take your time, there is a huge difference when you do it right) then glue it up. heart wood mixed in isnt a problem at all, ill post a pic of one i made for keenan.
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There's not allot on this one but I've made one with the limbs 50/50 heart/sappwood
(http://i1287.photobucket.com/albums/a631/jamesbowyer89/20130225_191725_zps5f88a718.jpg)
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Thanks Bowman.
When you say "take your time" can you give me a little more detail on time and temp. When I adjust with temp I usually get it to too hot to touch. Do I go hotter with tempering. I have read that you get it to the point of the wood starting to blacken. I would think that I would aim for consistent color the length of the bow.
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make a lil set up that will hold the heat gun 4" above the limb, turn it on high and let it stay there until the limb starts to darken to a dark golden brown. then move the heat gun 1" down the limb and repeat the process. there is going to be some trial and error as you go so pay attention to how long it takes to get the right shade of brown. you want to toast it not burn it. to finish one limb itll take around 45 minutes so take your time.
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make a lil set up that will hold the heat gun 4" above the limb, turn it on high and let it stay there until the limb starts to darken to a dark golden brown. then move the heat gun 1" down the limb and repeat the process. there is going to be some trial and error as you go so pay attention to how long it takes to get the right shade of brown. you want to toast it not burn it. to finish one limb itll take around 45 minutes so take your time.
Very good young Jedi!
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make a lil set up that will hold the heat gun 4" above the limb, turn it on high and let it stay there until the limb starts to darken to a dark golden brown. then move the heat gun 1" down the limb and repeat the process. there is going to be some trial and error as you go so pay attention to how long it takes to get the right shade of brown. you want to toast it not burn it. to finish one limb itll take around 45 minutes so take your time.
Very good young Jedi!
thank you sensei
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only took me 5 bows to realize how much i was rushing through it and how much i was not gaining in comparison to doing it the right way. that boa bow still hasnt taken any set
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Thanks for the description. I'll get it to floor tiller and then start cooking her. Will try to get photos up of the process.
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I think Dell said it best,
Something along the line of "if you are not bored to tears whilst heat treating a bow you are not doing it for long enough"
I make sure I have a drink, some smokes and some headphones to hand before I start. I also use a stop watch so I have a rough idea of how long I have done each section/limb. Some kind of holder for the heat gun too or after half hour your arm wants to drop off.
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Great advice given to you so far. Yeah, you can't rush it. You do need a jig to hold your heat gun. Here is my favorite. My caul is built on the edge of a 2 X 8 so there is room for the hammer.
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I gotta build me a jig for heat gun on my next one. I been doing about 30 mins a limb cause that is all I could stand!
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That one i posted is easy as pie and works great. I got a spring clamp and clamped the little wagner to the hammer handle at just the right height - done. I tried some other rigging, but this worked great for me.
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Howard,
That is awesome simplicity. I appreciate all the input from everyone. I think i will get it to floor tiller this afternoon and then set myself up to do the toasting while watching a game or the race.