I only made on sinew backed but it was ERC. I used Knox gelatin to make the glue and it seems to have worked and wasn't vety hard as long as you have a hot plate or something in your shop.
I had the problem that the sinew came out very rough on the outside, like very ridged not flat. Any advice from the experienced guys here? Did I not shred the sinew enough .... I was sgredding sinew for days ..,

Yes, you will be shredding sinew for days. The thinner you seperate it, the nicer it'll lay for you. Also, try applying smaller bundles of sinew and make sure they are flat like ribbons when you lay them down. I seperate the sinew until it begins breaking lengthwise, then back off a little, so it's pretty small in diameter.

When it dries, it will be rough on the surface, it's ok to scrape it and sand it to even out the surface. To help with a more even surface, you can also brush or wipe on a little hide glue after your last sinew layer, and also do it again after it's all dry, then scrape and sand again. You can make it really smooth if you like. I like a bit of a textured look... or cover them with snakeskin or fishskin, etc.

You can keep your hide glue mixture in the freezer until the sinew dries, then thaw it, and reheat it quickly for the leveling of the surface.

Thanks for the tips. Now I need to figure out how to automate the shredding .... I have a feeling the answer involves a 1/2hp bench grinder ..... No ill need gear reduction or belt drive reduction .... Anyone tried this?

i think it was in one of the TBB??? where they drove lots of tacks through a board, and used like a comb to shred the sinew into hair like fibers. might be worth a try

Pet de-shedder works great to make angel hair out of it. It does "waste" some of the finer strings, but hey. It beats yanking on sinew for days. I can process enough sinew in an hour to do up an average bow with 3 layers.

Hi Gang,
don't mean to hijack this post but I am working on a 60" Hickory Recurve, just in the process of bending the tips right now and am curious if any of you sinew guru's have found much difference in the sinew from different critters?
I have intended this bow to be sinewed from the start.
Thanks.
Bert.

I agree with Pearl that I can make all the sinew I'll need in an hour.  Similarly, I use a pet COMB to shred it.  Its a heavy steel but smooth comb that not only separates the sinew but breaks it down as I pull the sinew over the edge of the back of the comb.
When you apply the sinew you press it down and out with something hard so the sinew smashes out flat.  Don't overlap sinew bundles or you'll get the humps.  Lay the sinew bundles in a brick pattern and make sure the now stretched and goey bundle fits in the space provided correctly then press it down with and antler piece or something.

If you want a very smooth look then shred the sinew into hair-like bundles.  If you want a course finish then leave the sinew thick but soak it longer in the glue.  I use a big crock pot so alot of surface area in the bottom and the glue is shallow....so I can lay out the longest bundles of sinew in that wide pan and let them soak.

Bert,
I've only used deer and elk backstrap sinew.  No difference.  I want my sinew as long as possible so I go with those.

Bringing this back to the top with another question.  Once sinew or rawhide has been applied and dried does it need to be "waterproofed"?  I know there is no such thing as waterproof but I'm wondering if there needs to be some sort of coating applied to protect the backing.  Thanks!

-Jeremy  

I usually cover sinew backings with snake skins and tru-oil.  I just applied a snake skin this afternoon over sinew.