sinew backed turkish type short bow (lots of pics)

[inksoup]

firstly, this is not 100% turkish type. it has some issues from turkish type design but also has some others.
second, this is not build along, this is how i tried to make it.
last, unfortunatly bow has broken.
here is the pics.
1. just make it limbs bended little.
           
2. making the siyahs (kasan)
           
3. glued kasans.
           
4.
     
5. kasans
     
6. 2 mm lam for supporting the main limb wood. i think it is action boo isn't
   

[inksoup]

system allowed me to add only 8 pics at a time. so here is the rest.
6.5 bending it again.
     

7. sinew backing in place.
       
8. sinew again    
   
9. sinewed and let glue cure. btw, i applied 0.60 mm bamboo over the sinew.
       
10. close shot for kasan and sal connection point.
       
11. cured.
     

[inksoup]

and final.

12. details.

     
13. handle applied.
       
14. let it cure for handle.
       

oh yes, there is RD  
15. and finally broken.   :(  
       


here is the question i would like to ask.
i applied the sinew with epoxy glue. i think epoxy made it vulnerable. is it ok to use epoxy or do i have to use hide, gelatine, sinew etc. glue?

thanks.

[inksoup]

well i dont know why i cant see the pics but in case you cant see them here is the album location:
 https://picasaweb.google.com/104437810269533792634/SinewBackedShortTurkishBow?authuser=0&feat=directlink

[rainman]

Need to use hide glue or gelatine for sinew backed bows if you want the sinew to contract while glue is drying.  I have'nt used it but some guys swear by titebond II.  Did you use horn on the belly?

[mwirwicki]

I think that it is important to use hide glue for your sinew.  Why did you back the sinew with the .060 bamboo?

Also horn on the belly is important as it withstands the severe compression needed in a bow of this style.  How far were you bending it when it broke?  How long was the bow, overall?  How long were the kasan sections.

Also, it appears that you have a non-working handle.  It may be the reason the limb broke so near the handle.

The "straight-across" break often signifies dry rot in your wood.  However with the sinew/bamboo back, I'm not certain if the same would apply.

Also, I don't believe you're getting even clamping pressure by utilizing the cable ties.  You probably already know that traditionally the bows are bound with a rope.  Not having the rope gizmo, I used several C-clamps with soft wood pads with success, to spread the clamping pressure and squeeze the glue evenly.

[inksoup]

re: rainmain and mwirwicki;
i did not apply the horn but what i did at first place was applying 2mm hornbeam lam as replacement for the horn. but as you mentioned and i realised cable tides are not working properly when it comes to pressuring over it.

i applied .060mm (not inch)bamboo just to cover the sinew and make it good looking.  

the sizes, kasans, 250mm and sals are 480 from midpoint to far-end connection point of kasans. from end point of handle to starting point of kasan, sal is 310cm.

i don't know if the wood are dried, i bought them from Bauhaus which is big shopping mall selling such materials. i asked them, and they said no. maybe they are wrong.

can you please more specific about non-working or working handle?

btw, yes i know tradbows are bound with robe but it was easier to apply with cable tide. (obviously, i had to apply with some wood to make equally squeezed.)

thanks for all reply.
keep trying never stop, this is how i will learn.

btw: can you give me the sizes that the working bow you have done? sal, kasan, thickness, handle etc.

best.

[R.W.]

By using epoxy, I think that it made the sinew a solid, and may have caused your breakage.
"Hide" glue or fish glue, isn't as rigid as epoxy, and allows the sinew to shrink as it dries, pulling limbs into greater reflex, but also allowing the sinew to stretch as the bow is flexed to full draw.
Great project, and I hope your next attempt is successful.

R.W.

[inksoup]

thanks for all reply. at least i know where i made a mistake and of course will not be repeated.

except for hide or fish glue can i use sinew glue as well?

best.

[KellyG]

Insoup the natural glues are good. You can also use TBII or III from what I have read on here and III offers some moisture protection. I have been thinking about how I would sinew a bow.
I have never done it but I have been reading on here and going back to TBB series and reading.
I think I would use Hide glue on the back, let it cure, that will draw a bow into reflex. (according to everything I have read hide glue shrinks more then the sinew when it dries)
Then A layer of TBIII, then sinew soaked in TBIII. then a backing of some sort paper, rawhide, or cloth, soaked in TBIII. The TBIII just helps keep moisture out.
I will give this a go some day once I get enough sinew. I think I will do a short flat bow and use juniper. Just a thought, Since I have never tried it, it is a little out of the box.

[inksoup]

i was thinking the same with you KellyG. applying epoxy to all layers except for sinew. i do not know if this is gonna work or not.
well we'll see yours or mine.
before glueing the sinew i think it is necessary to dip it into warm water and make it soft and straight with the help of comp and then apply it to the surface (at least the bowyer in yotube is doing like this).
 http://www.youtube.com/watch?v=EKdb71kFmKo&feature=related

best.

[KellyG]

There are severel on here who have used TB glues, that is where I got the Ideal of that glue. Dont know if you have any or can get the titebond glues up north there or not. I had my wife ship me some here. I want try the sinew until after deer season, I hope to gather enough from myhunts and friends who hunt.
Good luck,
Kelly