Primitive Archer
Main Discussion Area => Bows => Topic started by: TurtleCreek on October 20, 2011, 08:14:28 am
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I am in the process of making a short sinew backed hickory D bow that I am going to back with sinew. The stave is floor tillered and about 5 inches longer than what the final bow will be. My plan is to make temporary nocks in the bow at the longer length so I can use a string to reverse brace it so it has reflex in it as I apply the sinew and as it dries. I then want to apply the sinew up to the base of where the actual nocks will be and then wrap it there to secure the ends. When the sinew is dry and cured, I then plan on taking off the excess wood above the actual nocks and then finish out the bow. Is this a reasonable plan or is there a better way of doing this?
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Also, would it be a waste of time to heat treat the belly prior to applying the sinew if the sinew is already going to be adding reflex to the bow and helping to reduce set or string follow?
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Sounds good to me,except Hickory is not all that strong in compression, wit a short D bow and sinew backed your tiller will have to be dead on all the way through the process or you will fret the belly.Good luck. :)
Pappy
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Thats solid advice from Pappy if you're doing severe reflex you might want to consider horn instead of wood. James Parker"Robustus" would be the man in the know on this subject. Shoot James a P.M. He'll probably help you out.Ronnie
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Yes that the way to do it.
When you heat treat it you should use a form and then you will be able to bend the stave into exactly the reflex you want and also remove any twists,bumps etc. This has the advantages over just reverse bracing it in that the reflex is permanent (until tillering!)rather than just pulled in.
If you can get the stave as close to final tiller as possible then the heat treating will have the most benefit - more resistance to compression,less set and you will get more reflex as the sinew dries.
If you do all these things just right then you will end up with a properly reflexed bow after tillering and shooting.
Remember that it will feel really heavy after the sinew dries so be careful not to reduce it too much. Again getting the tiller as good as possible before sinewing means you know it's ok to just brace it when dry which means you are a lot less likely to reduce the draw weight too much.
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Plenty of short reflexed Plains bows were sinew backed hickory and I don't think they had problems with fretting. Sinew takes a lot of the load off the belly in this design.
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I wouldn't be looking at adding any severe reflex to it, maybe only 2 or 3 inches.
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I would :D :D
4-6 inches :o then it will still be reflexed after tillering/shooting in.
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Sounds good guys. Thanks for all of the advice, this will be my first sinew job.
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I would also recommend reading Laubin's book online for more tips on this style of bow.
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I made a sinew backed hickory bow(Massey Medicine Bow) a few years ago. It is a great little bow...but...depending on the humidity or lack of it that bow can go from 45#@26" to 65#@26". If you live in an area of high humidity you may consider a wood that is less susceptable to moisture.
Also, check out the thread on my 53" sinew backed osage. I held the handle down with a sinew loop attached to a cup hook and lifted the tips up on blocks. Just another option.
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I have looked at that post several times Pat B and I think I may give that a try instead of reverse bracing
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I do it the same way Pat does with a string at the handle. Reverse bracing just gives me the chills! I cant help it.
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That's what I will do then. How much reflex should I pull it into before I apply the sinew? I don't want anything too radical, just something subtle- it will be my first time doing it.
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I thought about using string but decided if I used sinew it would become part of the backing and all I have to do when the sinew backing has cured is clip the sinew loop short and sand it smooth.
On the Medicine bow I did string it backwards when adding the sinew and braced a stick under the string to pull it into about 5" of backset. Now when unstrung she is flat. IMO if you live in the Eastern part of the US hickory isn't a good candidate for sinew...actually sinew backing isn't practical in a humid climate.
I'm building a sinew backed bow now. My first real shorty and will probably build a few more just to do it.
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What about Wisconsin in the midwest Pat B?
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I have two sinew backed bows I have kept around for myself. One is hickory and the other is osage. Both are 64" long, wide flat bows, and both are 50-55#'s. This is by NO MEANS a discredit to Pats observations, just my own add on's. I have never noticed either bow act or shoot differently in any weather I have had up here. If it was, it was so subtle I didnt notice it. I used TBIII glue on both, Im sure that plays a part.
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I also plan on using TBIII. Will the sinew backing still pull the bow into reflex slightly if I use TBIII?
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Probaly not pull it into reflex but you can add reflex. All of my sinew backed bows are made with hide glue. TBIII would make a big difference how moisture affects sinew but I don't think you get the same performance with TBIII as with sinew/hide glue. I've never used TBIII for sinew so this is only a guess on my part.
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My sinew backed osage bow has nothing more than 8-9 coats of Tru Oil over it. No skins or rawhide. The TBIII and finish seems to work perfectly together. My bows were sinewed with 3" of reflex pulled into them. I dont believe the sinew retracted enough to matter. Im guessing TBIII wont let the stuff move anywhere. Both bows are about dead straight now, thats after thousands of arrows.