As a gluten for punishment, I'm not too sure how many bows I've sinew backed but it's probably more than 50 and maybe closer too 100. Anyhoo, keeping with the primitive nature of things and working within the limits of natural materials, I've gotten away nicely with just greasing bows including the sinew backed ones... After they've been test shot enough to show that there aren't any hidden issues that would need to be dealt with. If you are gonna need a bow in rainy weather, consider using a self bow or a sinew backed bow that has snake skin backing to help prevent sticky sinew. If the sinew gets wet or damp, big deal, let the bow dry out... Sinew was born of water so if it every gets wet, it's not a killer. Something outside of this question though is how to deal with a sinew backing that goes all the way down to the belly on a very short highly stressed sinew backed bow. Because of compression , sinew likes to pull away from the edges if you carry it all the way to the belly, so I started wrapping my Cupid's shaped and Gull Winged Plains bows like this: They have generous tip wraps, and I also apply a thinned rawhide tip wrap to protect the sinew strings. I then put two midlimb wraps on each wrap, along with a center handle wrap. Then, between the wraps I make a nice and even criss cross pattern running down the limbs using long back strap sinew. Effectively, there is no more than 1/4 inch of unreinforced backing without having to fully wrap the bow, and the criss crossing looks way cool especially if the midlimb sinew wraps are covered with bands of scrap snake skin, going all around the bow. Sorry to be so wordy, John
