Primitive Archer
Main Discussion Area => Bows => Topic started by: Billbob on May 22, 2014, 11:26:41 am
-
Did my first sinew job last night on a 59"ntn maple pyramid, 2" at the fade to 7/16 tips. Used knox gelatin for the glue. Used sinew from the backstraps off of deer. Let the sinew soak in warm water for about 10-15 min then applied, did I let it soak long enough? I think I could have made the sinew finer. They were a little finer than the size of a #2 pencil lead. I put one layer on from tip to tip thru the handle and then I put another layer just down the middle of the limb. Was wondering if I should continue the 2nd layer to the limb edges and put a 3rd layer on? Also, was thinking of shredding the sinew finer and using it to smooth out the sinew. Can you do that after the other sinew has started to dry?
-
Give the sinew a few days to dry. It will become transparent when it is dry. I would use other sinew to fill voids and smooth out the sinew backing. As long as you haven't added a finish you can add more sinew later.
-
I'll add more sinew, but I'll try to get it finer. Some of the sinew I had was almost white when I shredded it and some of it was a light brown color. The white sinew is drying clear, the brown is staying brown at the moment.
-
I wrote a detailed sinew-along with multiple pictures showing the process for achieving a perfectly smooth sinew job without worrying about strand thickness or any of the other pitfalls of sinewing.
-
PatM's technique is outstanding and I highly recommend that you review what he wrote. You'll enjoy this!
-
+1 PatM and smoke
-
Tried PatM's method and it works great. Back is nice and smooth. Pulled it into a little bit of reflex for a couple days and then let it dry for about 2 weeks. Shot it and it seems to shoot well, but the reflex didn't hold and it didn' seem like the sinew pulled it into anymore reflex as it dried. Was the sinew not thick enough? Have about 3/4" of set. Can i toast the belly and or add more sinew to help hold the reflex?
-
Depending on the humidity of your area 2 weeks probably isn't long enough time for the sinew/gelatin to cure out.
-
You need to leave it for a good long time. Also pulling the stave into reflex by reverse bracing it BEFORE sinewing and then also tightening the string again after the sinew has been applied and the glue gelled.
With a wooden bow you should have at least 4 -6 inches of reflex to make the sinew start working.
Sinew/glue matrix comes out at about 1.3 s.g. - you've just got to make it 'work' or else all you've done is add loads of excessive weight. Remember your maple is likely only about 0.6 s.g......so the sinew/glue is probably twice as dense.
-
I think I only had it pulled into 2-3" of reflex. I have it braced at 6", if I lengthen the string a little and just reverse string it with that string it should pull it into 6" of reflex? Can I just rehydrate the sinew that is on it and put down another layer or should I just use this as a learning experience? I haven't sealed anything yet.