Osage Outlaw asked me to post some pictures of a recent sinew backing I did to a character bow. It's like a build-a-long, except it's already done. I guess it's more like a how-to.
Here are the raw materials, unpounded and pounded deer leg tendons, dried hide glue from 3RiversArchery, an ace bandage and a mostly tillered bow.
Dried hide glue up close:
Here's the hide glue ready for action in an old frypan. Rehydrating the hide glue is a long slow process, made tougher by the fact that it can't be overheated. I thought I'd try a pan with more surface area for a change, but the shallow depth kind-of offset the benefits of having more room to move the sinew around.
After a good degreasing with acetone, I use a metal cutting saws-all blade to rough up the bow's back.
The bow is first sized with hide glue, then the sinew goes down in bundles. I keep a pan of warm water to hydrate the sinew bundles in before moving them to the glue pan. I alternated the water and glue pans onto the hot plate to keep them warm but not too hot.
I was only protecting the bow's back from slivers with sinew on this bow so there's just a single layer everywhere but a thin spot by a knot where I was trying to add extra protection. You can see that spot just to the left of the handle in this picture.
I didn't center this picture well, but here the ace bandage is going on. I try to pull some tension in the bandage so it holds down the sinew well. Too much can cause the sinew to slide on the bow so be careful.
At this stage the bow looks like a mummy. I leave it like this for 24 hours to let the sinew adhere to the bow's back, then remove the bandage before it is so stuck down that it's hard to remove (and ruined). Notice the rag I used with acetone to degrease the bow before roughing it up. Osage oil stains like crazy. I'm giving osage a try as a smoking wood as I type this using some slivers off my current bow project. You can wash the ace bandage and the glue comes right out.
Here's that spot I reinforced with a double layer of sinew, another place on the bow with a single layer of sinew on it, and one of the limb tips.
Sometimes you can see the outline of the tape in the sinew when the tape comes off. Since I'm backing this bow with snakeskin I didn't worry about it. The bow was left to dry then for 2 weeks.
I ordered a pair of rattlesnake skins from 3RiversArchery, they matched nicely.
I did a quick check of the bow's tiller which in this case was still OK. After shooting it a little to be sure all was well (which was tough since I made it for a left hander) it was on to adding the snakeskin. After rehydratiing the hides, the skins are patted dry on a towel and a coating of hide glue is painted on the back. The bow back is also painted with hide glue and the skins are applied. You have a few minutes to position everything, work out air bubbles and make sure the hide is down tight before the hide glue sets up. This step has to be done carefully as the only way to get the hides off would be to submerge the bow and take off the sinew with the snakeskin. I wrap the skin around onto the bow's belly while it dries, then trim it off later to look better. Hide glue cleans up easy.
After the glue on the first limb is set up the process is repeated on the second limb.
Another 2 weeks of drying and the sinew related parts of this bow were done.
I suspect there are better ways to do this, let me know if you have improvements. I'm always learning.
George
