Sinew Processes ?

[willie]

A 1 to 1 ratio of sinew to glue is his reccomendation.On regular self bows less stressed I don't think it's that critical.Measuring myself on self bow designs or longer working limbs in paticular I think my ratio many times is 1 to 1/2 sinew to glue.Mass weight wise

How does using half as much glue as sinew seem different? Ed

for that matter, has anyone experimented to see just how much wet sinew actually shrinks, when dried, without the glue?

I painted just hide glue on a board, and it bowed from glue shrinkage alone.

[gfugal]

The reason I use old bed sheets is because they are thin and they breathe plus I only keep the wrap on for a few hours.

-my wife would kill me if I took her bed sheets...   I wonder what would be the cheapest substitute as far as clothe?

Go to walmart or any fabric store and you can buy fabric there. I bought some linnen there the other day. I got to say if your going to buy linen at a fabric store make sure you see what it's made of. Just cause it says it's linen doesn't mean it is. Most linen fabric nowdays is 100% cotten. I had to dig through 20 or so untill i found one that was actually made of linen. However, cotten should work for this purpose of wraping sinew though. Plus cotten would be cheaper. A yard of linen was $7.

[BowEd]

willie....OK...I'll ask you.How thick was that glue?Did you try different thicknesses?Did you bend it to find out the difference?Did you apply sinew with it?We're talking about strength here using more glue in shorter working areas opposed to longer working areas on a limb.Thicker is stronger.Higher percentage of glue to water ratio.The difference in stress between a pretzeled dried up short horn bow to a self bow is quite a bit.Getting more out of sinews' stretching properties.
Sinew will shrink all ways as it dries but more length wise then laterally and thickness wise depending on the width of the limb.A different percentage so to speak.Adam talks about that in his book too.
I'm not down playing Pat M's wrapping method at all.Just pointing out the versatility of sinew and hide glue into different designs.To me it helps infiltrate the hide glue into the sinew well too.With the added benefit of a smooth surface so little sanding is needed or waste of sinew and the time it takes to strip and apply more.I really can't say how much actual glue leaves when wrapped and heated.Never checked.Could be it's more water than glue.Could be to ask Pat M about that.I read where he does'nt think it's ever even close to starving it if you get to read his link.
I can remember doing my first sinewed bow.I'm sure there are others on here too.I thought filling voids with hide glue in my crappy first sinew job was a good thing.When I went to tiller it to get a string on it it crackled and scared the piss out of me.Nowadays I've refined my sinewing so that does'nt happen any more.To be exactly sure of the ratio that I applied is to weigh before applying and after it has dried and adjusting one way or another.More maticulas than needed just doing a normal 3 to 6 inch reflex on a self bow with longer working limbs IMHO.

[PatM]

It's all glue that comes out.  The water isn't going to separate from the gelatin just because it's warm and under pressure. You'd really be hard pressed to starve the matrix. It gets to the point where it packs down so densely that the glue deep down can't get out.

 Obviously I'm making it more of an art than science since I'm not measuring glue as I use it and then gathering up all the squeeze out and doing the math.

[willie]

 the less glue % the stronger the layup, at least with most composites. and if it doesn't take much to properly wet out the sinew and fill the gaps, the better? I think ed and pat are both agreeing on this?

I have got hide glue in different weights. some take more water than others. it is my understanding that it is like concrete, in that adding more water to a thicker glue, just makes it shrink more when drying, and makes the glue not as strong.

if the glue shrinks more than the sinew wants too, and adds to the reflex,  then that additional dried in reflex could be not as helpful as one might think.

just curious if anyone has experimented with sinew alone and maybe hoping  to understand what Adam has said, without buying the book.

[PatM]

I think we are but I also think Ed is saying that more glue is needed for a highly stressed short composite.

 Of course Adam would need to make a bow with way less glue or wrap and squeeze to prove that this in fact would be detrimental.

 I'm not going to assume that because Turkish bows were made a certain way that anything else MUST be wrong.

  For a wooden bow though I do like to follow the principle of minimal glue to fiber ratio.

[bradsmith2010]

nice,, I have been making sinew bows a long time and still learning and refining,,

[Stick Bender]

Patm ,Adam has probably did more research & experimenting with sinew/glue ratios then just about any body out there ,he went as far as dismantling ancient artifacts for dimensional purpose , those ancient bowyers where be headed if the bow failed for real , the guy is world renowned for his work I'm not saying he is the end all in the game but extremely respected  when he writes some thing it's with extensive research & exsplanation  I'm not saying that to be argumenitive I'm just saying if the guy writes it's because he has the boots on the ground research !

[PatM]

 So he did do the experiment I'm talking about? Cool. What happened?

[Stick Bender]

I dont know there Pat but you can email him and ask he is a down to earth guy that will actually respond to your email !

[PatM]

I thought it might have been included in the book if you were so sure.

I'm a bit puzzled why you started this thread now. 

[Stick Bender]

Its in my intro nothing I have posted contrary to that !

[PatM]

I just mean that if you're sure that Adam's method is the best then what more do you need?

[bradsmith2010]

where can I read about that,,

[DuBois]

Has anyone had sinew split down the length of the limb during tillering?

I have wondered about the white streaks that appear in cured sinew and if it is too dry when they are there or if that is normal.

And, do you guys usually put your cover over sinew after final tillering or some other time.

I like the PatM method the 2 times I've tried it. I used meat wrap with the wax side to the sinew and innertubes over that and it came off pretty nicely.