sinew , how long to wait

[Spotted Dog]

I just today sinew backed a little elm bow. It is 41" x 7/8" at handle to 5/16" tips. 2 layers of elk leg sinew.
How long do you all wait on dry time?  I put it in my car and wow it dried good. I have it in a sort of form
to hold some reflex. I used hide glue.

Dog

[Pat B]

I waited a month per layer. You are going to get lot's of different answers. 

[Spotted Dog]

I figured that one Pat.  This is the second one I have done. The sinew came out nice. Learned a lot on the first.
I think I went to working the other one after 2 weeks. Took a little more set.

Dog

[Tom Dulaney]

I waited a month per layer. You are going to get lot's of different answers. 

Howdy Pat,


Is it not advisable to glue more than one layer at the same time?

Sorry for intruding on your thread like this, Spotted Dog. I think peolple here are tired of me making threads all the time.

[Pat B]

I do one layer at a time with 3 total. If I add snake skin I give it another 2 weeks. A sinewed bow can dry for a year or more. You can tell as the draw weight increases over that time. In humid conditions it can rehydrate and dry back out as the air dries affecting the draw weight.

[Stick Bender]

There are so many different opinions on your question Im of the school of the slower the cure the better the matrix , there are so many different variables job to job, glue type , technique, RH etc I just finished the sinew on a bow put the first 2 layers at the same time & put the bow to slow gel and cure for 3 days at 55 deg 47% RH and 2 weeks later the finale layers for a total of 1150 grains & repeated the same 3 days slow gel & have the bow curing sinew side down to slow the cure at 72deg 50%RH  Im letting this one cure 2 1/2 months minimum its still pulling reflex on its own 1 month after first layers and 2 weeks sense finale layers , sinew still cures long after it dries the bow has stoped losing weight and still pulling more reflex , 1 size does not fit all you will get a lot of diferent answers !

[Spotted Dog]

 I truly wonder what/ how the native Americans did it?  I waited a month on tbt . 2 weeks on my first with hide glue. It took a little set , but I built into
it the gull wing design. This one just reflex.

[Stick Bender]

 The one you just made at only 7/8 wide & 41 in.  You probably only used 400 to 500 grains at max ? 2 to 3 tendons ?  It should cure fairly quickly I would think , the natives had the advantage father to son education same with the Asians !  Look forward to seeing your bow !

[osage outlaw]

I don't rush a sinew job.  I like to back a bow in the winter and then put it away until summer. 

[PatM]

Laubin thought 10 days was enough. I can't find a reason to argue with that.

[Spotted Dog]

Jim Hamm said in one of his books 10 days. But they continue to dry as to the sun or moisture.
I put mine in my car in the sun.
It has a knot in the upper limb which sticks out. Used a wrap at this area, because I didn't want
to take a chance cutting it too close.

Dog

[BowEd]

I've got a 5 year old sinewed bow that has'nt changed much in draw weight since I tillered it.They don't change any more here after being tillered then a self bow in poundage if you let them cure according to the thickness you put on and put a few moisture barrier layers on them.
2 layers of elk leg sinew will give you barely 1/16" thick sinew.You could tiller it within a month to 5 weeks.It'll be 90% cured.
Letting a bow cure in the wind on a warm day then being hung above a fire at night.It's not that hard to understand how the natives did it really.

[bradsmith2010]

laubin, said he saw no difference in long or short cure,,
and actually got less checking on belly on the short cure,,
so it really just depends, but I dont think curing longer is gonna hurt it,,
if you start to soon,, I think it might just change tiller more,, but I have done them in two weeks with success,,
I usually cant wait, so I just deal with it,,,if it gains weight, I know it was my fault,,
I am sure the Natives had varying opinions of processes as well,, Laubin was pretty thorough in explantion, and made alot of bows,, same with Jim,,
a small amount of sinew of a wood bow, I dont think is as critical, as some of the more advanced sinew and horn bows,, where the cure probalby made a difference,,

[Stick Bender]

Last year I made a hickory/sinew bow with in 2 months off the stump I cured the ruffed out bow for a month & sinewed the bow let the sinew dry for a week & then hung the bow above a heater vent to try to speed it up for another 3 weeks & the sinew cracked little lines not enough to hurt it but that bow picked up weight around 4 pounds after a while, it had 750 Grains of sinew & I made a maple/sinew bow 950 grains let it cure for a month it latter picked up 4 lbs , & I made a osage self bow that was off the stump 1 year around the same time & it later picked up 6 lbs I never really thought about that before as far as self bow weight change vs sinew good point Ed but there is always the question in my mind if I had been more patient & let them cure longer would there been a performance change for the better, less compretion stress with the backing being stronger etc, because even with a 2% change in backing strength is huge , but where late to the game this discussion has probably been going on for 1000s of years ! But just as interesting now.

[Pat B]

I know for a fact that R/H plays a big part in the workings of a sinew backed bow. I made a copy of Jay Massey's Medicine Bow; sinew backed hickory with a rawhide covering. All three of these elements are hygroscopic making this combo more susceptible to changes in the R/H. This bow I made came out about 55#@26". A month later it was 45#@26" due to the high R/H at the time. I sent the bow to Colorado for Kenneth to use on horseback and within a month it was to 65# because of the drier conditions.  This is one reason the plains Tribes use some sinew backed bows and the Eastern Woodlands tribes didn't. Eastern woodlands bows were usually longer and thus didn't need the sinew to protect the bows from overstressing where as the Plains Tribes, especially after horses were introduced, used shorter, highly stressed sinew backed bows. The eastern portions of the US have relatively higher humidity and the plains are more arid.
 Ed, do you think hanging a sinewed bow over a fire helped to add waterproofing because of the chemicals and tars in the smoke?