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Main Boards => The Bowyer's Bench => Topic started by: talkingcabbage on December 01, 2008, 11:28:00 PM

Title: Sinew questions
Post by: talkingcabbage on December 01, 2008, 11:28:00 PM
I'm wanting to try to back a bow with sinew, but haven't done this before, so of course I have questions...

The bow-to-be is a hackberry board-type bow, with a side-ways laminated handle of hackberry/walnut/hackberry (so the walnut stripe goes vertically up the middle of the handle area).  I've already backed the bow with 1/8" hickory.  I'm used to working with harder woods (osage, honey locust, etc) and as I was tillering, I totally overshot my weight by about 10lbs.  

My question is, can I back the bow with sinew on top of the hickory, and maybe induce a little reflex and add some weight?  I know that hickory is really good in compression, and with an 1/8" lam it probably doesn't make a difference, but what do you think?

Also, I've been saving sinew from deer that I've harvested this year.  About how many strips of sinew will I need?  The bow is about 65" ntn and 2.25" wide at the fades.  

Thanks in advance.  I'll try to post pics soon (prob tomorrow)

Joe
Title: Re: Sinew questions
Post by: Diamondback59 on December 01, 2008, 11:42:00 PM
yep  it will work  ya can maybe get 6 - 8 pounds if you  put 6 - 8 courses on it but you should be able to get the wt up   make sure you  use good quality hide glue and size the back real good  good luck  brock
Title: Re: Sinew questions
Post by: Chuck Homitz on December 02, 2008, 07:39:00 AM
pm sent
Title: Re: Sinew questions
Post by: talkingcabbage on December 02, 2008, 08:31:00 AM
6-8 courses seems like a lot to me.  I was under the impression that 2-3 would suffice.  regardless, approximately how many 6-8" pieces of sinew can I expect to use on this?  I've never pounded them out, so I don't know how many "bundles" will come out of one piece of sinew.  How much will I need to prepare?
Title: Re: Sinew questions
Post by: Pat B on December 02, 2008, 08:50:00 AM
Unless you just want to try sinew backing, if it were me, I'd add another hickory backing and add Perry reflex at glue up. By doing it this way, you can be shooting your bow in a couple of days.
   Hickory is strong in tension but not so strong in compression. A 1/8" hickory lam can add a lot of weight to a bow.
   Start a new short osage bow for the sinew to get the most out of it. Pat
Title: Re: Sinew questions
Post by: talkingcabbage on December 02, 2008, 09:42:00 AM
Thanks Pat.  That's a good idea.  Sometimes the simplest solutions are the most overlooked.  Thanks for the advise.

Here's the next question.  How much reflex should I induce, and what's "Perry" reflex?
Title: Re: Sinew questions
Post by: Pat B on December 02, 2008, 10:12:00 AM
Perry reflex is a glue up method popularized by Dan Perry, a flight shooting champion from Utah. What you do is pull the belly and backing into reflex at glue up time. Once the glue sets you end up with a little less reflex than was added. 2" to 3" of reflex is plenty to add and you should end up with a flat profile or slightly reflexed.
  By adding much more than 3" or so you add more strain so more isn't always better.    Pat
Title: Re: Sinew questions
Post by: Roy Steele on January 31, 2009, 01:11:00 PM
I don't think adding another strip will bring it up 10 pounds.I'd go with sinew.Doing this will add both weight and reflex.The more sinew the more you will add of each.
Title: Re: Sinew questions
Post by: Roy Steele on January 31, 2009, 01:15:00 PM
I don't think adding another strip will bring it up 10 pounds.I'd go with sinew.Doing this will add both weight and reflex.The more sinew the more you will add of each.