adding more reflex

[Renacs]

  I've been working on a Osage sinew backed recurve. Its more of a fun bow, where im just trying to push the limit. It is 54” long and about 1” wide tapered down to 3/8”.with one heavy layer of sinew. Right now its drawing 40# @28”. My questions are. 1 can I add more reflex with my second lay of sinew? Or will that cancel out some of the strenght of the first lay? Since it wasnt relexed as much. My second question is. Could I heat treat it more. And one more thing is that the working part of the limbs are very skinny, maybe 3/8” max. Im open to ideals. Its just a fun bow.

[M-P]

Howdy,  Ok here's my thoughts, based on a fairly limited number of sinewed wood and sinewd horn bows.  Yes additional sinew can add more reflex and will provide a little gain in draw weight.   To assure gain in reflex, it helps to 1)  Add a little additional reflex to the bow before sinewing.  2)  Add a little more reflex as soon as the glue gels.  3)  Gently put in a little more reflex over the first few days of drying.   Wait  ~ 6 months for the sinew and glue to fully cure/ dry.  All of this assumes you're using collagen glue (hide glue,etc.) 
Ron

[steve b.]

I mean this is one of those projects where no one is really gonna know what more sinew, or more heat treating is going to accomplish, for sure.  Since its a fun bow you might just go ahead and see.  From a practical standpoint I would say, don't touch it, you can't improve it.  What you might gain in poundage you might lose because of the mass. 
I personally stop thickness tillering at about .4" thick and go to side tillering, on a full sized bow. 

[M-P]

Hello again.   I've got to second Steve B's opinion.   Yes you can do these things, but should you?   That said, I occasionally find myself "fixing it until it's broke".   I did successfully heat treat the belly of a sinewed osage bow.   It took care and luck to adequately heat the belly and not over-heat the sinew, but I did it once and I'm glad I did.   I have yet to markedly reflex a wood bow with sinew, but I am currently working on two horn bellied bows and one yew paddle-bow were I am doing exactly as described in my first post to achieve something close to tip touching reflex.  Such marked reflex puts a large strain on the belly and takes a long time to achieve.  So...is it worth doing if it risks breaking your bow?
Keep us posted!   Ron

[mikekeswick]

There is no point really because you have had it to full darw.
No you can't heat treat it because you have sinew glued on and the heat will kill the glue.

[Renacs]

Thanks guys.  I think my next step will be .adding a heavy lay of sinew on the working part of the limbs and flip the tips.(its more reflex than recurve). What bout putting more  reflex in the handle portion? Stripn that part of the sinew off. Maybe even add a piece of bone or antler there, then more sinew. And i did use hide glue. So i can always recycle the sinew if things go bad.

[Pappy]

What Mike said. no offence meant here ,but it is really funny at the different perspectives on this site,some will go to all out extremes to repair a bow and others will go all out to ruin one and some are just happy with a bow that will
shoot an arrow and try and move on and make another one better. To each their on I always say. :)Good luck with your project.
 Pappy

[SLIMBOB]

Well said Pappy.  I've embraced all those positions at given times.  I'm sure all on the same bow a time or two.

[NeolithicMan]

heat treating with sinew already on? will that gel the glue or crisp up the sides of the sinew? If not then I have a bow to re work!

[Renacs]

No offence taken. I value your opions. Im not really trying to repair the bow as much as im just trying to see what i can get away with. This is just my little side project thats not being made for anyone, i kind of exspect it to fail. But if not great then. Im lucky to have enough wood to play with
 

[steve b.]

I think there is a lot of value in experimenting.  For one, you find out for yourself what works and what doesn't instead of relying on the experience of others.  Sometimes you end up surprised that what didn't work for them works for you.

I just removed the sinew from an osage bow and I had to practically set the sinew on fire with a heat gun to get it to come loose.  I would try the treatment and keep an eye on the sinew to see if its softening.  I think it was Badger who treats without toasting and keeps the gun moving, paying attention to the odor.  That's what I would do in this case.
You could lay the back of the limbs on some foil.  Then push up from underneath, the foil, such that its pinched agains the sides of the bow so that heat cannot access the sinew.

If in the end the bow gets ruined, send it to me and I'll throw it away for you. 

[PEARL DRUMS]

If we all did the same thing on every bow, this place would be boring as heck.

 I would think adding more sinew would shift the neutral plane closer to the back and in effect lessen the belly's job, hopefully negating most of the compressing you've done to the belly already. Cant hurt a thing trying. I do all kinds of stuff Im not supposed to, always have.

[Buckeye Guy]

Careful what you are admitting to there Pearly !!
 Renacs , play all you want it is yours !
 And yes Pearly I have done a few things I maybe should not have also !!!
Guy

[wood_bandit 99]

I say go ahead. Sounds like experimenting to me and nobody ever learns without it! I made a bow and tillered it with a heavily violated osage back. Worked and I would say it is nearly my best bow ever made! Worked for me not for others. Try it!