Author Topic: Short staves- draw length and draw weight trade off  (Read 453 times)

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Offline jameswoodmot

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Re: Short staves- draw length and draw weight trade off
« Reply #15 on: Today at 10:34:55 am »
Well, that didn’t last long! I’ve been trying to get this gas burner heat treating method sorted but it’s being a real pain. There are so many variable to getting it set up I’m finding it hard to work out how long to cook stuff. Also, with small diameter staves there is that gap where the back can get cooked.

I started with these western red cedar slats. Smelt like a sauna until it smelt like a burning sauna. They didn’t last long.

I had the burner on the ground and then realised at ground level there are all sorts of gusts and breezes blowing the glaze around.

Then I lifted the whole thing up and balanced it on various things. (Which is what I was trying to avoid) and then it worked better.

Then I cooked it all the way through!

Ive decrowned it as I wanted to see if it was the hot air getting to the back or if it was cooked through and it looks like a combination of both.

Just cooking the other limb to match now.

I’ll back it, options are; Ash, bamboo, sinew. What do you reckon?don’t think the bamboo will work without deflexing it in the middle.

The last photo is of the decrowned back
. The photo of the burner is just when I set it up, it was about 6” away in the end

I’ll get this thing sorted one day. I think I need a larger burner with more hole, there or four rows, and less flame per each hole.

Offline jameswoodmot

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Re: Short staves- draw length and draw weight trade off
« Reply #16 on: Today at 12:16:21 pm »
Couldn’t help myself, got a slat of black locust cut and planed. Any reason that’s a terrible idea?

I’ve also cut another piece of elm, a little shorter than the original, to continue with the plan. I’ll just not be heat treating it with gas 😂

Offline jameswoodmot

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Re: Short staves- draw length and draw weight trade off
« Reply #17 on: Today at 01:11:45 pm »
Too slow I did it anyway


One heat treated elm/ black locust stave.

I’m have zero investment in this, I might work but I’m not 100% about the backing strip, got a pin knot in it that I didn’t realise until I was flexing up was on the back side of the strip not the belly side as I had intended for it to be. Just got mixed up.
Glueing with cascamite and I scraped the mating surfaces with a hacksaw blade.

I use silicon spray on the bed of the thickness planer, I ran the glue surface over the belt sander and then scraped and then cleaned with isopropyl. Silicone spray is possible the worst thing for a glue joint so I hope I got it all!

The new elm stave is going to need some work to get it straight



Offline sleek

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Re: Short staves- draw length and draw weight trade off
« Reply #18 on: Today at 02:21:47 pm »
Elm makes some of the best bows. Its not a common wood only because of the Dutch elm disease.  Its has an interlocking grain so id wager it makes a fine backing. That silicone spray may be the death of this though, as once its on, nothing removes it. It coats sandpaper when you try to sand it off, only making you grind it deeper into the wood. Perhaps a scraper can scrape off the layer the silicone is one to remove it all the way. Im watching with interest.
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Offline jameswoodmot

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Re: Short staves- draw length and draw weight trade off
« Reply #19 on: Today at 04:01:46 pm »
Fingers crossed. Good job I have a lot of faith in cascamite. I used a 24 grit 2.5 meter long belt so it’s a lot of abrasive surface area and very aggressive. The bits that come off are more like saw dust than sanding dust, I think I got it off.

It’s got a stupid amount of reflex, I ended up with more than I expected in the elm stave, and I expected the bl backing to straighten it out when I glued it up but it didn’t much at all

If I can get 30lb at 20” I’ll be very happy with it. Then I’ll probably get too over confident and break it 😂

Offline superdav95

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Re: Short staves- draw length and draw weight trade off
« Reply #20 on: Today at 06:06:52 pm »
Yao could have saved you some trouble going down the rabbit hole of gas burners.  Too bad.  They didn’t work well for me either.  The only things that ended up working for me was a good heat gun which take a lot of time even if you build a holder, and a hot coal bed.  The coal bed is the best in my opinion to get a thorough cook.  You will benefit from protecting your back with a heat resistant material like insulation or insulating foil perhaps.  I used a roll of pink insulation layer out on sticky foil tape that worked.  I’ve since moved to roxul the green stuff held in a strip with foil tape and then weight that down as is cooks.  I find it doesn’t send glass fiber floaties around in the air like the pink stuff does.  Anyway some thing to consider for next time.  I also don’t heat treat woods like western or eastern cedars or junipers or yew really.  At least not the same as we would with white woods.  If doing corrections in twist or alignment fixes use steam. It will make the corrections more safe and drastically reduce your splinter lifts or breaks if done right.  Overheating can cause wood to become too brittle and snap.  White woods generally take more heat better the other woods even Osage.  So long as you take measures to avoid too much wrap around heat effect on the stave white woods can tolerate a lot.  I’ve got many hhb, hickory, elm and others in white wood category that have taken darker then normal heat cook over coals and been great shooters.  Even bamboo is a great candidate for heat treatment.  I know a lot of guys don’t do this but for me I’ve found some noticeable benefit from doing it.  If using bamboo for backing only heat treatment on the non rind side.  Especially for backing.  If using a bamboo backed and bellied bow then there is benefit to doing a treatment on the compression belly side boo only.  Some of my fastest bow have been these ones.  Anyway lots of info here on the forum.  Do some searches I’m sure you’ll see some good examples to give you a good reference.  Message me directly too if you like. superdav95@gmail.com
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