Sinew and Hickory

[MLombard]

Hello..I am wondering if it is possible to Sinew back a Hickory Bow.  I have heard that it could cause compresion fractures on the Belly...true or not?...Also, I read a thread not long ago about using TB 3 and watering it down in place of Hide Glue, I did a search and could not find it so and thoughts and expierence would be helpfull..Thanks

[Lukasz Nawalny]

hi, I have made a lot of hickory/sinew bows and in my opinion it is very good idea , but bow should be possible short and with recurve, couse high mass of hickory wood. I use fish glue , more elastic then hide glue

[Pat B]

I made a sinew backed hickory bow that I copied from Jay Massey's Medicine Bow. 60"t/t and pulled 55#@26" when done. A month later when the humidity was high the bows weight dropped to 45#@26".  a few months later I sent it to a friend in Colorado to play with and before long it was back up but to 65#@26". In a dry climate I'd say sinew backed hickory would be an ideal set up but if you live where humidity is high your bow will fluctuate as the humidity does.
  Sinew is compatable with TBIII glue but you won't get the same performance boost as you would with hide(or fish) glues...but it won't be as affected with moisture when TBIII is used either.

[JW_Halverson]

I have a sneaking suspicion it was not so much the sinew and hide glue that was affected by the humidity as it was the hickory underneath, Pat. 

All that lovely hickory seems to want to grow where the humidity lowers it's value as a bow wood.  Here where it's dry enough to excell, it won't grow!  Maybe that's a survival strategy. 

[Pat B]

John, all three components are quite hygroscopic so all are susceptable to moisture. My sinew backed osage bows fluctuate some with humidity changes but not as much as the hickory does.

[johnston]

Pat what do you use to "seal out" the moisture on a hickory bow?
MLombard do you live in a high humidity climate? How do you seal hickory?

Lane

[footfootfoot]

I'm not sure if this is heretical but the best material for stopping the transmission of moisture is shellac. Shellac from the Lac bug. Better than varnish, oil, or even wax. If you build up enough layers of it, it can be rather water resistant without going cloudy.

Buy the dry flakes, super blonde is clearest, and dissolve in denatured alcohol. There is a lot of good info on Shellac on the web. It's all natural, non-toxic and awesome.

[Pat B]

I use Tru-Oil on all my bows.
  It isn't water that is the problem with hickory or sinew/glue, it is humidity. As the wood breaths it takes on moisture that has saturated the air. This moisture increases and decreases as the humidity rises and falls. The wood has to breath or it will dry rot. So with a finish you are trying to slow down the hygroscopic rate, not eliminate it.
  A combination of shellac and linseed oil makes an old standard bow finish called French Polish. I think you add them an ingredient at a time and many times to build up a good finish.

[JW_Halverson]

Alternatively, you can move to Texas.  Seems like most of that country don't know what moisture is these days!

[Lukasz Nawalny]

I use shellac to

[PatM]

Dry rot? Apart from the fact that there really is no such thing the typical moisture cycling in wood has nothing to do with "breathing". It's just the fact that  "dry":things in the environment will try to reach their equilibrium with the humidity level.
  No bow (ecept perhaps a whitewood bow in a tropical jungle) is in any danger of rot of any sort unless it is actually totally abandoned to the elements.
 It's nice to think of formerly living things like leather and wood as still breathing but "porous" is a more accurate term.

[MLombard]

Hello..I live in West Central Wisconsin..I'm thinking of using Massey Finish...Epoxy with Acetone mixed One part Epoxy and Three parts Acetone.  In the Summer we have humid times but in the Fall and Winter the Air is Dry.

[PatM]

The thing I don't quite understand about Massey finish is how it ended up being that ratio of epoxy to acetone. There seems to be some debate as to whether it is five-minute or regular 2 ton that is thinned. There is a biig difference between the two.
 It is well known that epoxy radically drops in moisture protection capability when thinned even slightly.
 A couple of drops of lacquer thinner actually works best with minimal impact on moisture resistance.
 I'd  just go with a regular coating epoxy. 

[MLombard]

From the way I understand it, the Acetone aids in penatration of the Epoxy..the more the Acetone the deeper the Epoxy will go into the Wood...I dunno..its just the way I've been told by someone.  I've used it on Knife handles and for Finish over Snake skins..its turns to a very hard finish.  The other Finish I'm thinkin about is the True Oil route..I've used that for various projects with great results also.

[footfootfoot]

According the Gougeon Brothers (West System) the faster an epoxy sets the weaker it is. Could be splitting hairs, though. I haven't got the data at my fingers.
Slow curing and warm temps will allow the epoxy to penetrate/saturate too.