Uncut with Ed Scott...interesting point on glue for sinew backing

[osage outlaw]

I use the knox gelatin glue for sinew backing a bow.  The only failure I had was my fault for not degreasing properly.  I used cooking oil while heat straightening and didn't get it cleaned enough before sinewing.  After getting it degreased, I sinew backed it again with knox and it has held ever since.

[Marc St Louis]

Personally I've always felt that a natural glue is better for performance than the modern plastic glues even in hard backed bows, I use plastic because it is convenient.  The unknown with plastic glues is their rate of return after being stretched and/or how will being stretched repeatedly affect them.  Will they return to their original configuration as fast as natural glues once they are stretched?  Do they have the same elasticity as natural glues?  After repeated stretching will they have the same molecular shape or will their molecules be permanently stretched.  Sinew and hide glue can be stretched up to 4%.  Can sinew and plastic glues be stretched as much without being adversely affected?  I know that TB3 will shear when used on horn in a horn bow, hide glue does not.  Obviously plastic glues will fail at a much lower stress level.

[fusizoli]

Hide glue have hellical molecule structure and PVA glues have not. They have different characteristic and the modern glues can't do the same thing. So Marc point the most important thing in this.

[aero86]

ok, so my question now is, will the titebond hide glue work ok for a sinew backing?  of course, regular hide glue is best, but on the last two posts, got me thinking i should try titebond hideglue instead of titebond 2 for sinew backing..

[fusizoli]

I dont know the TB hide glue. But if a hide glue could use for long time it have to be preserve it somehow. If it made chemical (I dont know other method) way than it will be weaker than the original structure.

I ve read my books again and, just found good things from gelatine(long molecule structure,high elasticity and strong bond). So I have to change my negative opinion I ve wrote from it. I will give it a go on a wooden bow to see what happen but dont want to risk it on a hornbow. I ve used gelatine just in my work as a paint restorer. Still think it is weaker than those I ve used on bows before. Will see....

I ve used rabit hide glue, hide glue, bladder glue and PVA, epoxi glues on bows. Just the first three for sinewing and some tests with PVA.

[Gaur]

in terms of the water proofing of the old ways... I had a conversation with Jaap about this.  He had a horn bow, a really old one, that he wanted to study so he soaked with with water for days and still had trouble getting the glues to give away so he could dismantle it.  He has it all in a frame showing the construction.  I like the old ways better and think they were done for a reason.  I have TBIII and TBII on hand but I like making my own glues from sinew and fish bladders.  Also like the color better when they dry and believe the part about the chemical nature and how they are made of the same material as sinew so they should bind better than a manufactured product.  I also like Ed Scott and his bows are great and he is welcome to do it how he likes 

[Badger]

   I wish I could find a good source for fish bladders. I like the color of the fish bladder glue as well as the properties. I also like the tb hide glue, I used to use nothing but liquid bottled fish glue I bought from lee valley years ago and had pretty good luck with that. It tended to feel tacky when my hands got sweaty and that was my only real complaint about it.

[Gaur]

I could hook you up with that Steve.  They have bags full of them at the markets here.  Not super cheap but not outrageous either.  I think I paid about $15 for a good sized zip lock bag of them.  Someone else wanted some so I am going to go pick some up soon.

[mullet]

 When I sinew back a bow with Tight Bond, I will thin it way down and lay it on the bow. Then I will come back and put multiple layers of TB3 to help with moisture. And I have taken TB3 and stretched a piece that was about four inches long into a rubber band about 8". And, there is no way, till further research , I would try to glue a horn bow up with anything than GOOD hide glue if I wanted it to last for 400 years.

[Kegan]

When I sinew back a bow with Tight Bond, I will thin it way down and lay it on the bow. Then I will come back and put multiple layers of TB3 to help with moisture.

Do you mean you size the bow first with TBIII, or that you lay the glue-soaked sinew down first and then layer more TBIII on top to help water proof it?

[aero86]

id like to know your secret as well!  lol.  does anyone think you could put multiple layers of sinew on with tite bond?  or should you build it up the way you need to all at once?  this is a good experiment for what im doing..

[mullet]

Kegan, I'll size it first, and then run the sinew through a bowl with thinned down Tight Bond, squeezing the excess with my fingers and lay it down.

Aero, no secrets, it's just simple. Be sure one layer is dry before you put one on top of it. And it takes a longer time to dry than you would think.

[fusizoli]

Mullet I ve done a very simillar experiment. Just not on a bow.

Try out abot 5-6 kind of D3 PVA glues I could by hear. Put a fat layer on a silicone paper and let tham dry for weeks at a warm, place.

All of tham was pulled with the same weight and with hand too. Some of tham was better, but all of tham stretch like rubber just not turn back for the same size as rubber do.

PVA glues working fine if use it a very thin layer, like between two compressed wood. In a sinewing process U couldn't press all the glue out so it will contain a relative big procent of glue.

One of my learned friend wrote her thesis from PVA glues in paint restauration and she done a lot of experiment. All of tham was dryed out and streched in controlled conditions. She had the same conclusion like me.

The best I find here is a Pattex D3 PVA wood glue for all wood. It was the best (harder and less strechy) in my experiments and in this thesis too. I use this in my work and for bows nocks etc. It is still not enough strong for lamination so I think TB III schould be stronger.
 I couldn't by TB glues here

Another important thing! All PVA glues could form with heat. So if U push a piece with hot iron (between silicon paper) it will melt a bit at about 60-80C.
I dont think it is a good thing if use the bow on a warm sunny day