Sinew Processes ?

[Stick Bender]

Willie I was hoping some body would chime in on some of the glues you mentioned my only experience is with hide glue,Rabbit skin, and liquid hide glue as far as natural glues but maybe the following will help this is info that I found threw research , the molecular composition of hide glue is                                                                     
Carbon 51-52%
Hydrogen 6-7%
Oxygen 24-25%
Nitrogen 18-19%
Total 100 %.       It's soft gel strength is rated in gram strength usually between 80 to 250 for practical glue ,the higher the number the quicker the gel ,for general purpose hide glue is usually 140-250 GS  all the natural glues are rated under that system Hide Glue (Including Knox) being the highest in the chain and fish & fish bladder glues being the lowest , but those numbers can be deceptive because it gives you the impression that the higher number would be the stronger glue but it has nothing to do with the cured strength of the joint only the soft gel density & the molecular weight , 80 GS glue will pull wood off before the glue breaks so like Tim Baker said the lowest grade Hide Glue will work , but just because the sinew won't pull off the bow is not the whole story , the way the glue primarily works ,in the way I understand it is most of the strength comes from the big players Carbon & Hydrogen bonding & the oxygen & nitrogen being minor players but the vast majority of the bonding occurs while the glue is still placid so the slower the gel & the slower cure the stronger the joint that's why fish glues end up being the strongest even though there not as dense as others , I'm no expert or trying to be just sharing what I have learned but understanding how & why the glue works has me rethinking how I do things for a better sinew job !

[willie]

Stick
maybe I should have presented the question a bit differently. It is a bit of a stretch to think that someone would be able to cite experience with all the different glues that were listed.
I have read that fish glues gel slower, but beyond that, it's hard to tell glean about the relative working times. Maybe folks could share the differences between the two or three they have tried?

I thought knox was bone glue?


Seems that maybe my other question about drying times might be too subjective to elicit a qualified response also.

What do you think the best way to tell if the glue/sinew matrix is cured.  Can you weight the bow for weight loss, with any accuracy, like you might when drying a green stave?

[Stick Bender]

I don't know exactly what goes into Knox I have read bone & pig/cattle skin , I don't think weight is a good system for judging cure because I know with my current curing bow after the first 2 layers & 2 weeks of cure time the weight loss slowed to a crawl the only way I know is time & RH  I'm letting my curent bow cure for 2 1/2 months or longer, curing sinew is a whole different thread I have herd so many different cure times it also depends of the amount of sinew used & how thick ,my bow I used 1150 grains in only 49 in. working limb if you start to soon like after 1 month you some times will have to re tiller over time Adam actuly has a chart in his book for cure times !

[BowEd]

Lots of off shoot subjects connected to the main subject of sinewing processes with the different glue types and sinew types.I'm defeinitely no expert either and usually always try to get a common denominator  from different sources of info to come to a decision on things.Like Ritch said the slower the time it takes for all those molecules to align themselves during the gelling stage does help in strength for the cure and strength.
In other words a person should let the freshly sinewed bow gell and partial cure in a cool place at least the first couple days.
You've gotten more info on the subject Ritch then I knew about the percentages of different molecules in glue,and a good explanation of what ones are most important.
Personally I'd like to have a little air bladder glue around to mix with the sinew glue for better moisture resistant and strength qualities.After sinewing using a tannic acid solution glue from tree bark for a sizing over finished sinew for water proofing reasons.Possibly smoke the bow too.Besides putting a birch bark or snake skin cover on too with tite bond 3.All of these steps and barriers I'll call them[air bladder glue mixed in/tannic acid based mixture hide glue sizing/smoking/and birch bark to get a sinew job that's more then strong enough with moisture reisisting qualities.

[PatM]

Cool temp speeds up gelling though.  if you think prolonged gel time is beneficial you would be wrapping the bow to keep it in that state.

[BowEd]

Yes cooler temps promote quicker gelling.Wrapping and heating if done would reliquify to regel later for wraps to be taken off.

[Stick Bender]

This bow I left in the shop after gelling for 3 1/2 days I got lucky & we had a 4 day rain storm & the bow stayed at 48 to 54 Deg 51% RH  & the gel was still softer at that point it keeped it from drying fast it's been 2 weeks sense last layers & 4weeks sense the first 2 layers and it's pulling 6 1/2 in of reflex on it's own I'm going to let it cure another 1 1/2 months !

[Stick Bender]

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[Stick Bender]

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[willie]

the slower the time it takes for all those molecules to align themselves during the gelling stage does help in strength for the cure and strength.
In other words a person should let the freshly sinewed bow gell and partial cure in a cool place at least the first couple days

just thinking out loud, but if slow cures make a difference, then maybe not drying , and shrinking the sinew too much to begin with, would also help? Has anyone tried to freeze it for storage, and dry just enough to shred before using?
 
Any info on primitive sinew collection and prep out there? I have been looking thru some old Smithsonian anthropological and materiel culture publications, and find much about the collection of objects, but little on observations of methods.

[Stick Bender]

I don't think it would suck up any glue in that state I have never herd anybody doing it !

[willie]

Why does it have to "suck up" the glue?

[Stick Bender]

I would think for solid bonding ? But you could try it & see , but I would think if there was a advantage it would have been done some where ?

[willie]

Yes, I suppose that it would need good bonding. That is usually accomplished at the surface boundary. I think that's what the slow cure helps with. In general, there are some myths about the benefits of a glue to be able to "penetrate", but that's beside the point. My thought is, good bonding is only good until things start unbonding. It might be beneficial to have a glue and sinew that shrinks at the same rate in order to maintain a good bond. I would be interested to find out how people who used sinew tools everyday of their lives, worked with their materiels. To frame my question a bit different, can anyone point to a primitive source that indicates drying the sinew hard was a necessary part of making the magic happen?

[PatM]

You can just soak sinew and pull it apart while it's wet. The drying is for preservation to a large degree.

Pounding it makes it fray to a degree,  but stripping excess glue largely makes all those potential links run back unidirectionally.

You will actually find multiple methods of sinew application across the globe with similar end results. 

Some of them don't even involve soaking the sinew in glue but rather laying them on glue and painting more glue on top.