TB3 for sinew.

[Digital Caveman]

So, I want to put one layer of sinew on the 54" HHB I am working on to help hold the reflex.  I have rawhide but no hide glue or Knox.  How does TB3 work for sinew on bows?  I use it that way on arrows.  I would prefer to use that because I have it, I already know how to use it, and so I don't have to worry about moisture.  How long would I have to wait for a 2mm layer of sinew to dry before I can start tillering?
Thank you,

[Pat B]

It can be done, many have successfully but I prefer hide glue. The TBIII will cure in 24 hours but the sinew will take longer because it will be encapsulated in a waterproof matrix.

[Digital Caveman]

Ok, so if I did that how long before I could tiller?  If I squeeze out all the extra glue and put it in a cool, dark place I expect the sinew could dry better.  What about not soaking the sinew, just running it through thinned glue?

[gutpile]

the problem with using ttb3 for sinew is it dries too fast not allowing the sinew to work its magic ...it will protect the back still but not work to its full capability...  JMO.. gut

[Digital Caveman]

What if I reverse bend the bow while the glue dries?  I would like the extra reflex to avoid stack, but I primarily want the extra elasticity.

[PatM]

Buy some gelatin.  Problem solved.

[Digital Caveman]

I don't have the time, I am moving in 3 weeks, and I will have to stop bow work at the end of August.  Also, gelatin is moisture sensitive.

[gutpile]

you can hang weight on handle and it will help pull in reflex.. ... the magic of sinew and hide glue is hide glue slow dries..ttb3 cures pretty fast... hide glue mixed with sinew while its drying can take months .. so does the natural ability of the sinew to pull in reflex .. all about patience and time my friend.. either you got them both or not... time seems to be your nemesis right now... there is always another bow to build...gut

[Digital Caveman]

Ok, that sounds good.  I'll use TB on this one and start tillering later this week, it may not be the best sinew can do, but if it's really strong and elastic that is good enough for me. 

[SLIMBOB]

I think you eliminate sinews greatest strength using TB. It’s ability to shrink while drying, using the shrinkage as a a performance booster. All kinds of test have been done that bear this out. Knox is cheap, easy and you can buy it nearly anywhere.

[Digital Caveman]

Yes, but I don't have time to cure it, let alone finish the bow with enough time to build another back up for the trade by the end of august.  Also, I am headed to a place with 80% humidity in the summer. 

I pulled the bow into 4" reflex and put on a layer of sinew down the crown.  Either there will be a lot of retained reflex or the the sinew will be nicely prestressed.  Anyway, for a first go it's not too bad.

P.s. This stave came from a 2" diameter stick, so I put the sinew on the crown, but skipped some of the edges.

[Pat B]

Would you put a pot in your full kiln if it only looked dry?   

[hoosierf]

I’ve done some just like you did but never prestressed reflex into the bow. I’ll be interested to see how much it retains.  Good luck with it. 

[Digital Caveman]

@Pat, Yes, I know what dry clay looks like. 

Just joking, what do you mean?

[Pat B]

 How will you know when the sinew is dry enough to work on while tillering the bow. One layer is sinew might not be enough to keep the bow in reflex anyway. You could put the bow on a caul in reflex and heat treat the belly then add the rawhide backing with TBIII and probably achieve the same goal.
Sinew is a hygroscopic material. It takes on available moisture and releases it back to the atmosphere as per the R/H. Even if you put the sinew down dry it will absorb moisture from the glue then after the glue sets up it will slow the release of the moisture from the sinew because it is waterproof.