Sinew Questions

[cool_98_555]

Hi guys,

Well I've never backed a bow with sinew before, but for some reason I really want to try it out.  I just finished an osage bow that is 66" long, 64" ntn, 1 1/8" wide and draws around 93# at 29".  It took around 1.5" of set.  Also, after about 50 arrows through it, it started getting these tiny cracks around the only 2 knots on the back, which were already raised humps.  I want to put sinew on the back for reassurance so I can get to full draw without having to worry about splinters anymore.  Also, I would love to brace the bow backwards and impart some reflex while the sinew is curing for a few weeks so I can get all the performance I can out of it.  I realize sinew performs best on shorter bows, and I am willing to cut this bow down to 64" or 62" and apply sinew while it is braced backwards.  Or I could leave it where it is at its current length and just apply 1 layer of sinew because of the long length.  I'm not sure what I should do.  Open to suggestions on length but if I am going to cut it I wouldn't want to cut it shorter than 62" for my draw length of 29".  It does have a rigid handle (no arrow shelf).

[PEARL DRUMS]

That length and width is EXTREMELY short/narrow for that draw weight and draw length. Add about 3/4" to the width and about 6" to the length and you would be more happy. You have war bow numbers going on with a 50# hunting bow lay out. Adding more reflex will only challenge it more, even with sinew. I would suggest rawhide on this bow and see how long it lasts. Then on your next effort make it to the numbers I suggested and leave it un-backed.

[Pat B]

2x what Pearlie said.

[bradsmith2010]

since we really dont know what the tiny cracks are,,
its hard to advise,,,
but Pearl is right,,
the amount of wood you have for the 90# bow is not enough,,

rawhide might hold it as suggested,,

sinew would have worked if the back was not damaged,,
but its unknown if it would hold not knowing the extent of the damage,,

if you just want to  practice with sinew backing,, then go for it,, it wont hurt the bow,,
it will increase the draw weight, ,and you will have to re tiller for that,, but probably wont improve performance

you should test the bow for its performance as it is,, and then after sinew,,
 
and I doubt putting sinew is gonna gain anything for you,, as a fix,, possibley prolonging the life of the bow,,

sinew bows perfrom better if the bow has not been shot in before sinew backing,, like maybe to half draw and then sinew back,,

I have sinew backed bows ,, with compromised back,, some success and some not,,just to learn what it would do,, your case is iffy,, 

sinew bows can perfrom well in longer format,,,, if the sinew is applied with that in mind, and tillered to fit the profile,,

[osage outlaw]

I think that a bow should be designed and built for a sinew backing from the very start.  Putting a sinew backing on a bow with issues or to add weight isn't the best use for it.  That's just my opinion. 

[cool_98_555]

Thanks for the replies guys.  I think i'm going to get some rawhide and back it so I can have some assurance it won't break on me from those tiny cracks.  I just don't like shorter bows (Less than 62"), so I probably won't ever have a need to back with sinew.  Thanks for all your input guys.

[Pat B]

Put super glue in the knots and the checks at the knots before adding the rawhide backing.  Rawhide and other similar backing materials will not keep a bow from breaking but it will give you a little insurance.

[PEARL DRUMS]

And, if it does let go it wont be so violent. Just a gentle fold-over. Or, your tiller will go WAY out of whack.

[Stick Bender]

You could also do a thin tapered comb flax patch on the problem areas prior to the raw hide it has worked for me in the past those areas might be a tad stiffer but not much !

[Danzn Bar]

I agree with most of the above....the wood is damaged, save the sinew, use rawhide and shoot the heck out of it and until it fails and build another.....JIMHO...
DBar