Author Topic: Bending and Skinning osage (Read 5943 times)

Knocker · « **on:** February 20, 2009, 01:12:25 am »

Hello all,

You may remember this bow I posted a couple of years ago. It was my first bow, and I have enjoyed shooting the heck out of it. It has developed a fair amount of set. Mostly due to our rainforest hunting weather in the NW and lack of a really good sealing finish I imagine. I felt like I could still learn alot from this bow, and hopefully enjoy shooting it some more, so I talked to a few members offline about bending osage with dry heat. You can see the results in the photos below. Not too radical of bends because it's my first try at dry heat, but I think a nice improvement. The right side JUST came out of the clamps & jig right before the photo, so the curves may yet relax a bit. For yet another first, I would like to back this bow with a sturgeon skin I have. I will search the archives for the good posts I remember seeing on that subject.

So, my questions to you:

Should I check the tiller to see how much bending the limbs has changed it?
Sturgeon skin is more like rawhide than snakeskin in strength. Should I back the bow with the skin before tillering?

Part of the reason I am thinking of backing this with sturgeon is because I am worried the bending may have weakened the wood somewhat. Seems like the backing would make it bulletproof and also reduce the chances of the set coming back. I also think the skins are awesome looking on the bows others have done.

What do you all think?

Thanks,
Keith

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Pat B · « **Reply #1 on:** February 20, 2009, 01:24:54 am »

Have you stressed the bow any since you made the changes? Adding the static curves will stress out the working portion of the limbs and can cause more problems. You may be able to temper the belly and get better results. I don't know if you will get enough benefit from the skins as you want. I would wait to be sure the bow comes out OK before skinning it.

Knocker · « **Reply #2 on:** February 20, 2009, 01:28:28 am »

No Pat. I haven't put a string on it or even floor tillered since bending. I thought I would let it stabilize for a couple of days before doing anything else. And quiz the forum about tillering or skinning first...

Keith

Pat B · « **Reply #3 on:** February 20, 2009, 01:32:59 am »

How skinny is it?
Letting it stabilize is a good idea! Let's see what others say before you stress it!

FlintWalker · « **Reply #4 on:** February 20, 2009, 01:58:23 am »

I'd give it a day or so, then brace it. You'll have gained some weight by recurving it, so that's something to consider. I think before I stressed it very much, I'd heat treat the belly. DON'T force it to bend into any reflex since this can cause cracks on the belly. Just heat it and if it naturally pulls into some reflex on it's own it shouldn't hurt it. By tempering the belly, it will somewhat harden the wood and help minimize any more set.
From the amount of string follow you already have, the finished profile will look like a reflexed/deflexed recurve.
I would do all I'm going to to it and shoot it alot before putting the skins on it. I've wasted good skins before from jumping the gun and putting them on bows that hadn't proven there worth.

Good Luck

Knocker · « **Reply #5 on:** February 20, 2009, 02:33:42 am »

Pat - the bow is 1-1/2" wide to 3/8" at knocks. I'll post another photo showing the width.

Saw Filer - A little more weight would be OK, because I think I would like to get the outer limbs bending a little bit more than the original tillering. This Sturgeon is tough stuff! I think that will raise the weight a bit too... Using a heat gun, I heated the (olive oiled) belly to too hot to touch as I was bending to the jig. Would this give me the tempering you are talking about?

Thanks!
Keith

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Pappy · « **Reply #6 on:** February 20, 2009, 07:11:18 am »

No thats not hot enough,you want to heat it till the wood starts to change to a light golden brown,not burnt but just change color a bit.Then I usually lay it up for a few day and let it rehydrate before re tillering. With the recurve and heat treating it should gain 6to 8 lbs.So you will have some room to tweak the tiller if need be.

Pappy

Timo · « **Reply #7 on:** February 20, 2009, 08:40:02 am »

All sound advice here Knocker.Whatever you decide to do be sure and retiller. Heat tempering does change the tiller. Be mindful.Works well on some bows. I ,like the others here would recommend getting the bow hunt ready and be happy with it, before adding any asthetics. I answered your other question on my thread. Good luck. It looks like a nice bow.

GregB · « **Reply #8 on:** February 20, 2009, 08:43:18 am »

Because it is a used bow, I don't think the heat treatment will have the full benefit it would on a new bow...although it should help and like Shannon and Pappy said, add some draw weight. I don't think the sturgeon skins will add any draw weight at all...only added weight on the limbs. It should add some protection against splintering just as rawhide would. If you want to take the time and trouble to sinew back the bow, it might help it retain more of the reflex after the bow is shot in.

Hillbilly · « **Reply #9 on:** February 20, 2009, 10:02:11 am »

Be sure to let it rehydrate for a few days. I didn't let this one rehydrate and it didn't do so good when I pulled it back:

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Knocker · « **Reply #10 on:** February 22, 2009, 03:11:13 pm »

Sorry about your bow Hillbilly. Did you use oil when you were heating? The belly of my bow turned a nice golden brown, and the olive oil I was using smelled like cooking popcorn! :-) This was my first time for using dry heat, so I was surprised at how easy the osage bent. I did 3-4" at a time, and it just turned to rubber when it was hot enough. I have bent vine maple with steam, and it was still pretty stiff when bending it around the form, but then I had to take the stave out of the steam and bend the whole curve in one shot.

Keith

Knocker · « **Reply #11 on:** February 23, 2009, 12:21:11 am »

I spent some time in the shop today. I was amazed at how much bending and tempering the wood up'd the poundage. I'd say Pappy was right on or even a bit conservative with his 6-8# predicted increase. I had to do a fair amount of scraping, and I am still not to my original 50# at 28". I might leave this one a bit heavier and use it to build up the strength in my left arm! :-)

I have done some more sanding and have also lightened the wood on the left tip since these photos. I have exercised her a lot on the tillering tree, and I continue to have a lot of faith in this beautiful piece of Osage. If it quits raining for an evening, I hope to put a few arras into a hay bale this week. If she holds together, I am going to get the sturgeon skins on her.

Keith

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Pat B · « **Reply #12 on:** February 23, 2009, 12:55:10 am »

She's a real beauty!!!

Pappy · « **Reply #13 on:** February 23, 2009, 07:56:53 am »

Very well done,that thing looks good.

Pappy

Pappy · « **Reply #14 on:** February 23, 2009, 08:01:09 am »

That turned out nice,very well done.

Pappy

Primitive Archer