need help tillering a sinew backed bow plz.

[akila]

Hy guys i wood realy apreciated iff you could help me a little with this bow.its a sinew backed bow ash, its 175 cm long and my draw length is 72 cm.I made a picture with the bow on the tiller stick.Im waiting for your advice.Thks. a lot.

[Hillbilly]

Looks like you're off to a good start. I would start getting it to bend just a bit more out of the fades and work out the limbs from there. Go slow, and exercise the wood a lot between scrapings. If my cm-inches conversion is accurate, the bow is 70" long? That's way long for a sinewed bow, seems like. I'd probably shorten it several inches myself. Sinew on long limbs can add a lot of weight and bog it down. How many courses of sinew are on it?

[akila]

Hy ..yess the bow is 70"....and i must be onest ...i woudn want to shorten it..becose i already have make the tips with cow horn and i realy  dont want to do the tips again.I put 2 layers of sinew.Can you plz tell me whatt do you mean by "out of the fades"? sorry for the stupid question .but im not verry familiar with those therms yet. .

[Ryano]

He means where the Ridged handle "fades" into the working limb. 

[akila]

Here is another picture after some more scraping...do you see any diferens... ??


Ant this one is made with the bow strung a little more...35 cm with a long string.

[Ryano]

Looks good enough to get the short string on it.

[akila]

Well....here is another picture after some little scraping....i wass trying to put a little more bend in the middle area of the limb and this is the result..
.
How short the string should be... and at this moment it pretty heavy...it pulls @ 55# on a 16" length with the long string.The bow has already taken some set..1" of deflex.Maybe the wood would come back to his initial form  ?  im thinking that the sinew will pull back the wood...but who nows...?

[welch2]

Looks good. Do you have an unstrung picture? How long has the sinew been on?  You can take the sinew off ,back to a typical sinewed bow length ,to get rid of the extra mass problem Hillbilly mentioned .Just wrap the new ends of the sinew .

Ralph

[akila]

I made some new pictures....here you can see where the sinew stops...just next to the tips.In the next pictures you can see that the bow has taken an all most 2" set and in the last picture you can see a full draw of the bow.Its  70" long bow, and its 65# with an 29" draw lenght.I dont know why the bow has taken this set..and i must say that its not the first time whenn this happent to me on a ash bow.I have made 3 mounth a go a flat  long bow with the same lenght 70" and has taken the exact set like this one here.The plans to build the boe i got themm from this site:http://www.vintageprojects.com/archery/bow-plans.html.I must say that i did not treat the belly of the bow with heat gun..so...this is it...i dont know whatt to say.

[a finnish native]

are there any compression fractures in the belly of the bow near the handle? I would definitely get it bending more from the middle of the limbs and not so much in the near handle region. not that the tiller is awful, but for a sinew backed bow to work well for many years, the tiller has to be spot on perfect. it also takes some time to get the bow bending after reducing wood.

[akila]

are there any compression fractures in the belly of the bow near the handle? I would definitely get it bending more from the middle of the limbs and not so much in the near handle region. not that the tiller is awful, but for a sinew backed bow to work well for many years, the tiller has to be spot on perfect. it also takes some time to get the bow bending after reducing wood.

There is no compression fractures on the belly of the bow...but i didnt apsect the bow to take this set....specialy that the bow is sinew backed....so you think i should bend it more in the middle area of the limb?
Hello guys...i have done some more scraping on the middle area of the limb and this is how it looks.Probably will look much better after using and bending the bow a little more and after shoting some arrows with him.Can you give me some ideeas for a finish of the bow?? i know Snake skinn is realy good but i dont have something like that here so...i wass wondering if i can put some nitrolack on him.I dont know iff this is how its spells this word but the stuff is used for finishing on yahts or bowts..(sorry for my english).
.

[Mark Smeltzer]

With the bow taking that much set I would think that the sinew may nor be fully cured.  Even if it has been on the bow for some time it may not be dry enough if the humidity is not low enough to force the moisture out.
The tiller is looking better, I agree the outer/mid limb should be working more because of the length of the bow and the fact that it is sinewed. 
Just my opinions.
Take care.

Mark

[George Tsoukalas]

Did you string it with the long string? If not you should. Long string tiller looks good. Set is something the beginner should not worry about. IMHo.Jawge

[akila]

With the bow taking that much set I would think that the sinew may nor be fully cured.  Even if it has been on the bow for some time it may not be dry enough if the humidity is not low enough to force the moisture out.
The tiller is looking better, I agree the outer/mid limb should be working more because of the length of the bow and the fact that it is sinewed. 
Just my opinions.
Take care.

Mark

The bow wass stay a mounth and 2 weecks to cure....i dont know aboute the humidity... he wass stayin inside the house where it wass aboute 25 degrees celsius.The outer mid limb is the part right in the middle of the limb,or just a little more to the tips???And can plz.. somone give  me and advise on whatt finish i could put on this sinew bow,,to protect the sinew from thumidity?
And yesss the bow wass string with a long string first, and thenn i have shorten the string and i strung the bow to an 3" of deflex and i tiller again.Right now the bow pulls 65# at 29" draw lenght and have 2 " of set.The bow have a realy smouth draw...i mean i can pull it verry easey, even iff its 65#.Thks a lot for your help..this is my first sinew bow so....im learning
I just remeber something that i might be important...the sinew that i used ,is domestic cow...you think that it has any importance??could this be the reason that the bow has taken this set..?It wass the only sinew that i could find arround here so...this is it

[a finnish native]

I think you just found the problem. sinew, like muscles develop to certain needs, and domestic cow's sinew is not even half as good as moose or deer sinew. You could put that stuff that they use on boats to protect it from moisture. even then the draw weight depends dramatically on the time of the year and the moisture content of the air.
My sinew backed bow had 45# when I finished it around December last year, and in march it pulled 72#