Primitive Archer
Main Discussion Area => Bows => Topic started by: Blacktail on January 21, 2010, 11:18:37 pm
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this is for the people that have done sinew backing...in your own opinion...in one course or layer of sinew how many pounds do you think that it adds to bow weight...NOW,i know that it depends on some other factors as well(wood type and so on )...i am just try to find out some round about info about poundage...thanks john
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the title was off the wall question..sorry about the miss spelling.
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John, I think with one layer you are only adding protection. But maybe a few years later, after curing you will pick up a pound or two. I've seen bows with 3 courses gain about 10 pounds in 3 or 4 years if they are kept dry.
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I imagine each course adds more pounds than the previous one, because of the increased leverage of lying further and further away from the wood.
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hey thanks eddie,i have an oak bow that i am working on its 54" and has 2 courses on it...i have it tillered out to 10" with a 4 5/8 brace...and i put it on the scale and at 10" its 18 pounds and its gains 2 pounds an inch..i want to at least hit 20" of draw.if i figured it out right..at 20"right now its only going to be 37pounds..so,i was thinking of add 2 more courses..to gain weight...this is why i asked about pounds and courses...maybe i shoulded have added this..sorry guys..john
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John, adding more sinew isn't going to automatically make the weight jump up. You will be adding mass, or weight to it if you keep adding sinew. I have seen the weight go up after a few years with 3 courses of sinew applied with hide glue. But, in that dry climate you live in you will probally gain it quicker.
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My last Sinewed Bow is now 4 years old....Ash Stave....3 full Layers...one down the Center....Finished out at 56 at 28"...is now up to a Scary 73 at 28"....as is as fast as a Rocket...but creaks and clicks like theres no tomorrow...and maybe there won't be...one day....... ;D.....I attribute the massive draw weight gains to the fact that the Humidity here is next to Non-Existent...and the Hide Glue and Sinew has dried so fast that it has added this much so fast...Bow demensions....58 ntn....1 1/2" wide at fades....last 12 inches tapering off to 1/2" Tips
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Unless you are adding reflex while sinew backing, you are mainly adding blow out protection.
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In my experience, if you're sinewing with hide glue or knox, you add anywhere from 0-2lbs with the first layer, 2-3 lbs per layer after that.
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There are too many variables to give 1 answer. I reciently took off too much weight tillering a sinew cedar bow. It had 3 layers of sinew. I added another 1.5 layers and it went from 39# to 52#