Sinew: Theoretical Question

[Comancheria]

No, I do not plan to do this, but am interested in the theory:

Suppose you were to take a very thin strip of hickory--say, 3/16 or 1/4 inch thick, shape it as desired, and then, not just back it with sinew, but surround the whole stick with a thick layer of sinew and hide glue--basically, a modern recurve or longbow with sinew and glue in place of glass and resin:

How would sinew do in compression on the belly of the bow?

Would you be able to tiller such a "stave" by scraping down the belly sinew?

Was this ever done by aboriginal peoples?  I have found no references to such a procedure--so I suspect there are good, theoretical reasons why not.  Clearly, sinew was an "expensive" commodity in primitive cultures, and clearly, too, it might have made a gooey mess in wet weather.

Any thoughts?

Russ

[PEARL DRUMS]

Sinew has zero compression value. Its all about elasticity with sinew.

[Comancheria]

Thanks, Chris.  Does the lack of compressibility in itself mean that it would not aid in the prevention of chrysals in the underlying belly wood?

[PEARL DRUMS]

Correct sir

[Comancheria]

Gotcha.  Thanks.

[JackCrafty]

There have been a couple examples of Native American bows found with sinew on the belly but there is doubt about whether the observers were looking at the belly or back. 

Sinew has some compressive value but this deteriorates quickly while exercising the bow.... at which time it becomes mush.

There are clear examples of NA bows with sinew on the sides as well as the back.  Apache bows with rectangular cross sections were sometimes made this way, for example.  The value of having sinew on the sides is a subject for debate.  In my opinion, the value is very small: kind of like having sinew on the non-bending portion of the tips.

[Comancheria]

Pat. Your response triggers another question--which I had been saving until I actually need to back a bow.  That said, I will now engage in a favorite activity of mine--hijacking my own thread. 😳

I have seen references to running the sinew over the tips and a few inches into the tip bellies, then cutting nocks through the sinew.  Is this a common practice?

Best regards,

Russ

[JackCrafty]

Yes, the practice of cutting the nocks through the sinew was common.  Just as common, I think, was wrapping the sinew over the nocks after carving.

[Comancheria]

I suppose you couldn't (or wouldn't want to) do the same wrap over the tips with rawhide?  Due to the thickness?

[JackCrafty]

Some rawhide is very thin (coyote for example) and can very well be used instead of sinew.  Gut can also be used.  Sinew was just the easiest option back in the day.

[Comancheria]

Well, having broken my first, I am naturally a little wussy about buildimg another self bow.  I am going to try a maple bow using BBA (Bubby's Build-Along) but then may try a 48-52 inch bendy handle and back the dog out of it with sinew.  I know I am committing the mortal sin of thinking I can make up for lousy tillering with a backing, but what the heck?😊

[JackCrafty]

Go long on your first bow.  It's easier.

Not everyone can make a 48" bow with 60lb draw weight @ 26" draw.   

[Comancheria]

Believe me, Pat, I will.  I am even going to ask Bubby (in fact, am asking right now😊), what he would think of lengthening his build out from 66" to 70 or 72--and widening it near the handle from 1 3/4 to 2".

[JackCrafty]

Cool.