New bow started(again, 1/4/2022){ and again 8/10/22}

[superdav95]

Ed, I haven't tested the weight lately and it really doesn't matter at this point. I can tell by floor tillering it will be lighter than a hunting weight bow. If I can get my finished sinew backed bow to come out at 40# to 45# I'll be happy. I will also be adding a thin rawhide backing over the sinew. My main concern is getting the overall bow tillered well and adding a good sinew layer to it. I can still go back and heat treat more before sinewing.

In your picture I seen you had this bow close to your full draw tillering.Personally I don't like to stress the wood hardly at all before sinewing.I try to not go past 20" drawing it.Then extrapulating a ball park estimate within 5#'s of what the draw weight will be at 28" or your full draw.Then with the knowledge of knowing what depth sinew will give the bow I can usually get within 5#'s of full draw weight while needing to remove very little wood from the belly while tillering.
I think it gives the bow prospect the best chance to be a very efficient bow broken in.
I've found reheat treating numerous times does'nt actually help much.Once it's stressed the stress goes deeper than just the surface on the belly along with the stretching on the back.Even though sinew goes over the back.

This is what I’ve been finding as well. +1 for what Ed said.  I usually get just past brace then sinew it.  Ed’s right on this from what I’ve noticed in my bows.  I stick with 50% wood/25%sinew/25%horn.  On wood and sinew only bows it depends on the width of the limbs but generally a standard flat bow 60%wood/40% sinew by thickness.    Stressing the wood prior to sinew puts more stress on the sinew then there needs to be.  Having a balance share of stress on the combination of sinew glued to the unstressed wood core makes for a better more efficient bow in the end.  Looking good so for pat.  Lookin forward to rest of this build. 

[BowEd]

That elm is some good bow wood Pat.Look forward to seeing what you get from this design.
When tillering there's a certain weight I want at 20" that will conform to a 45 to 50 pound bow after heat treatment.That's usually around 32 pounds + or -.
Most all good dry bow wood will not show stress at that draw length unless badly tapered or too narrow for design.
Every pound or two less than that will lose close to 5 pounds of full draw weight.
Knowing the thickness of sinew I need I then can put that amount onto the bow to get my preferred full draw weight.
Like Dave said percentage overall wise.
50/25/25 percentage core/horn/sinew is a good more stable percentage because of the thicker stabilising core.Going 33/33/33 percentage will be more unstable.More time consuming and having a wild child on your hands for a while because horn is a lot more elastic than wood,but it's still doable.Using a peg board helps settle them down.The added benefit of thicker percentage horn will help for less set also.
It's still a little bit of a guessing game but it'll put the bow very close to what is desired.Being slightly overweight is good though.It leaves room for fine tuning the tiller.
This works for me on bows from 58" long to 68" long.I'm sure going shorter might change some of the estimates.

[Pat B]

Ed, I took your advice and went back and re-tempered the bow on the reflex form darkening the color a good bit. Here is where she is right after removing her from the form...


I have not strained her yet since tempering. We have been in a wet period for a couple of days with a couple more rainy days to come. Once we dry out a bit I'll check the tiller out to 20" then prepare for sinewing. Her overall length is 65"t/t with about 18" to 20"of working limb on each side. In the end the t/t length will be shortened by maybe 2" after I shape the tips. I've been thinking about how I want to shape the tips to reduce as much weight as possible without weakening them or losing the lateral stability.

[PEARL DRUMS]

You are getting closer now, Pat. Don't screw it up

[Pat B]

You know me all too well, Chris. 

[PEARL DRUMS]

I'm working on a lumpy yew Hill style self bow that I'm waiting to knock me in the head!

[Pat B]

Don't forget the pics...the bow and your broken head. 

[bradsmith2010]

I dont think you need to check the tiller out to 20,, put the sinew on without straining it at all,, that being said,,if you are more comfortable checking it to 20,, I think the only difference would be in my head,,,

[superdav95]

Brad.  I am currently working on a relaxed Scythian style horn bow that I just placed my first sinew layer on.  I did not brace this one or draw it out to 20” like I have done before. Instead I carefully measured thickness with calipers on both limbs to be as close as I can get them.    I’ve done sinew backing on bows from fully shot in to just at brace height.  What I’ve seem is that the less strain you can place on the core prior to sinew the better.  That being said I do agree with Ed that it’s worthwhile doing some mild pre bending to sort out most if not all tillering issues prior to sinew.  Going to 20” on a good clean piece of wood that’s been heat treated (white woods) or knot free defect free Osage or yew for example will save a lot of tweaking and time later and won’t hurt the wood core really if bend looks good.  I’ve had good luck going to brace or just past it to end up with fast bows that recover well.  Stressing the wood core is like using substandard wood as your core.  Ok maybe not the same thing exactly but imagine you take a fully shot in bow that has settle in at it’s final draw weight and cast. It’s reached it equilibrium of stresses on both the belly and back.  By adding sinew as a backing to such a bow you will more then likely see increased poundage and cast if the sinew was placed on properly allowed to cure and dry  and not overly done with glue to weight it down.  What I’m suggesting and I think Ed as well is that if you were to take the same bow PRIOR to being shot in and settled in with all the accompanying stresses of a fully shot in bow and then add your sinew you would have a better performing bow in my opinion and experience.   

[BowEd]

Correcto Dave....It makes a difference in the testing and hitting the draw weight dead nuts.Most of the detailed work is done before sinewing.
It's hard to convey all the details to someone unless they've done it themselves.If they are willing they can learn.
With a lot of reflex making sure tip alignment is correct is critical.
Removing lots of material from an over weight bow loses all the heat treatment.
That may not be critical using osage but with other woods it can be.It's part of the adventure of making bows.

[bradsmith2010]

the sinew always tricks me and comes in way to heavy,, or heavier than I expected,, just doesnst take much wood,, when you adding sinew,,,

[superdav95]

Sinew is an art on its own.  I’m still learning it’s subtle nuances after several sinewed bows.  Guys like Ed have it down more and I’ve learned from him.  He’s generous with his knowledge.  I think it’s a good way to be and it helps guys like myself who in the beginning was making mistakes with sinew.  I’m at the point now that I have less surprises and getting more of a system down.  It takes a while for sure and it takes just getting to it and not getting caught up in wasting materials I guess. 

Sorry Pat I feel like we are hijacking your bow thread!  Maybe we should start a new thread on applying sinew???  Ed you up for that???

[BowEd]

One thing I'm not into is explaining to skepticism when I know what's going on at both ends of the subject.
The hooks of individuals bringing up disingenuous subjects don't catch me any more.
Pat will sinew his bow the way he wants.It'll be a durable well shooting bow for what he wants.
A person can explain it but doing it is the best teacher if that's what they want.
They can PM me or you if they want.

[bradsmith2010]

this bow starting out great, will be fun to see it evolve,,I love making sinew bows, and enjoy watching the process of others as well,,

[Pat B]

Dave, I'm enjoying the info that you and Ed are sharing. Maybe starting another thread would be a good idea anyway so the conversations can continue uninterrupted.
 I've built 5 or 6 sinew backed bows and learned a little more with each one. The moose sinew for this bow was sent to me by a friend from Norway. The bow design came from a Danish relic from a 7000 years ago found in a fjord in Denmark. I don't know if this design was ever combined with sinew but I thought the design would be cool with a sinew backing. Ever since I first saw a Holmy/Molle style bows I thought it would be interesting to add sinew to the working portion of the limbs.
 The Norwegian name for moose is "elg" and for bow is "bue" so this bow will be named Elg Bue.