Author Topic: Reverse bracing sinewed bows  (Read 1802 times)

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Offline BowEd

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Reverse bracing sinewed bows
« on: November 08, 2012, 11:19:43 am »
I'm gonna bring up something that's been exciting me about bow making lately and maybe I can get some more insight from it from other people that have done it more than me.
Lately I've been reverse bracing bows that I've sinewed besides my other self bows made.As opposed to just letting the sinew dictate the amount of reflex at rest it gives the bow.For the sinew to be able to handle this I put on somewhere between 250 to 300 grains of dry sinew per foot of bow.To me sinew wants to work.I say let work.What is the amount of sinew other bow makers put on a bow?I suppose this is a personal preference question but I'm curious to what others have to say and in no way say my way is the best for each bow built or for each person.Maybe this should of been put in the build a long thread.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline Bryce

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Re: Reverse bracing sinewed bows
« Reply #1 on: November 08, 2012, 02:21:37 pm »
I also reverse brace by bows. Low reverse brace for the first course. And each course I'll reverse brace it a little more before each course. 3 courses in total applied over 3 days, and let to dry for about a month. Depending on the design depicts how much reflex I give it.
I'm not sure of the weight, but purchased a scale so I can take better notes.

-Pinecone
Clatskanie, Oregon

Offline tattoo dave

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Re: Reverse bracing sinewed bows
« Reply #2 on: November 08, 2012, 02:53:55 pm »
Great question beadman. I am very interested to know also. I am getting ready to start a few sinew backed bows for the first time, and would love to have some sort of reference as to how much sinew to start and end with.

Tattoo Dave
Rockford, MI

Offline BowEd

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Re: Reverse bracing sinewed bows
« Reply #3 on: November 08, 2012, 08:09:50 pm »
Thanks fellas....Personally I put my sinew on in two sessions.Always size the bow's back first.I do mine a week apart from each other.Reverse bracing it farther like Bryce each time.Ending up with close to 1/8" dried sinew on the back.Now it'll look like a lot more than that when you apply it but it shrinks down a heck of a lot.If a person can get the wet job to look nice and smooth your dried look will really be.Presoaking your sinew before you dip it into the sinew soup.The finer you can get your sinew the smoother the job too,and it's best to get them on there as straight as possible.Guess I just like what the stuff does for a bow's why I brought it up.There is no standard really just a personal preference from experience and what you want your bow to do.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline Bryce

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Re: Reverse bracing sinewed bows
« Reply #4 on: November 08, 2012, 08:59:32 pm »
Sizing is a must. I comb my sinew out on the bow, I also apply mine in the bathroom with the shower going and the vent off. That way it doesn't gel up to fast and I can get every piece exactly where I want it. I'm pretty picky out my sinew.

-Pinecone
Clatskanie, Oregon

Offline Kviljo

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Re: Reverse bracing sinewed bows
« Reply #5 on: November 10, 2012, 06:04:43 am »
Reverse bracing is a must when it comes to composites, both to take full advantage of the sinew, but also to prevent the sinew from lifting off of the bow back once it starts to dry and shrink. Put on the sinew first, and then pull the tips together a little. On the turkish bows one usually put on three layers of sinew, which totals about 100 grammes of prepared sinew strands. After putting on the last layer, the tips should be touching. This is of course not possible to do with a wooden bow, but for sure it is a good idea to at least pull it into a "reverse brace" once the last layer is on. More might damage the wood belly, unless the bow has been heated and bent into reflex before sinewing.