Author Topic: Durable, waterproof sinew backing  (Read 14119 times)

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Offline kevinsmith5

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Durable, waterproof sinew backing
« on: November 09, 2013, 10:17:31 am »
Once again as part of my "horsebow without horn so you don't get to use glass" argument I'm looking for experience folks have with doing a sinew backed bow where the sinew was both waterproof and the bow was durable. The more ways, more examples the merrier. As an ELB guy and only so far making Flatbows for kids I've no experience with sinew, so if the answer is "can't be done" feel free to say so.

Offline Pat B

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Re: Durable, waterproof sinew backing
« Reply #1 on: November 09, 2013, 10:29:58 am »
You will never completely moisture proof any wood bow, sinew backed or not. I use Tru-Oil on all my bows and get good protection from it., plus it is easy to repair if necessary. My sinew backed bows will get mushy in humid, moist weather. When the humidity is high I don't use these bows and keep them stored in a dry location. 
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline PatM

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Re: Durable, waterproof sinew backing
« Reply #2 on: November 09, 2013, 10:42:55 am »
Birchbark with Epoxy on top of the bark.

Offline Pat B

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Re: Durable, waterproof sinew backing
« Reply #3 on: November 09, 2013, 10:52:00 am »
I do usually use snakeskin or rawhide over the sinew  then seal over them.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Blaflair2

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Re: Durable, waterproof sinew backing
« Reply #4 on: November 09, 2013, 11:07:55 am »
That's sweet pat, kool look to the bark
Nothing ventured nothing gained

Offline kevinsmith5

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Re: Durable, waterproof sinew backing
« Reply #5 on: November 09, 2013, 04:11:40 pm »
Could you just epoxy over the sinew? Do all of you glue the sinew down originally with hide glue?

Offline PatM

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Re: Durable, waterproof sinew backing
« Reply #6 on: November 09, 2013, 04:26:24 pm »
Yes, you can just Epoxy over sinew. That's the method Jay Massey used. Massey diluted his Epoxy considerably before application but that's unnecessary and you'll get even better waterproofing by omitting the dilution except for a couple of drops of lacquer thinner.
 If you want your sinew to do real work, you'll use a collagen based glue.

Offline Pat B

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Re: Durable, waterproof sinew backing
« Reply #7 on: November 09, 2013, 05:42:42 pm »
I've used Knox for sinew but with mixed results. Now I only use hide glue.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline PatM

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Re: Durable, waterproof sinew backing
« Reply #8 on: November 09, 2013, 05:51:39 pm »
What could possibly go wrong with Knox?

Offline Eric Garza

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Re: Durable, waterproof sinew backing
« Reply #9 on: November 09, 2013, 06:47:29 pm »
I've always thought that Knox was just purified, powdered hide glue.

At any rate, I usually save all of my finely shredded sinew scraps and make glue with them on the spot by warming them in a small amount of water when it's time to back a bow. That way the sinew (or hide) glue isn't heated multiple times, which I think reduces its strength.

Offline Pat B

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Re: Durable, waterproof sinew backing
« Reply #10 on: November 09, 2013, 07:03:37 pm »
Pat, I had the sinew lift from the limb on two bows when I used Knox. It could have been my screw-up but I switched to hide glue and haven't had a failure or sinew lift since.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Fred Arnold

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Re: Durable, waterproof sinew backing
« Reply #11 on: November 09, 2013, 07:50:23 pm »
For you that save the hide glue for later use, can it just be refrigerated or do you need to freeze it?
I processed some  lately from my sinew and rawhide scraps and put in a covered plastic container in the fridge.
I found many years ago that it is much easier and more rewarding working with those that don't know anything than those that know it all.

akswift

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Re: Durable, waterproof sinew backing
« Reply #12 on: November 09, 2013, 08:26:30 pm »
The birchbark with epoxy looks very nice.

  But I have to ask, are you speaking about the performance of sinew

Quote
If you want your sinew to do real work, you'll use a collagen based glue.

if so, why do you think epoxy is inferior?

Offline PatM

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Re: Durable, waterproof sinew backing
« Reply #13 on: November 09, 2013, 08:38:48 pm »
Nobody suggested actually backing the bow with sinew and epoxy.  The reference was to PVA type glues.

Offline Thesquirrelslinger

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Re: Durable, waterproof sinew backing
« Reply #14 on: November 10, 2013, 12:14:48 am »
well, hide glue and sinew are chemically identical. so you get an incredibly strong, tough, close bond.
Hide glue is collegen.  Sinew is collogen. Both soften in water. epoxy just so happens to be hydrophobic.
"Insanity is doing the same thing over and over again and expecting different results"