I've had good luck sealing artificial sinew with Barge cement. Since I tie down my artificial sinew the Barge cement merely seals the sinew, holds the ties in place, and smooths out the sinew. Never had a problem with art. sinew unravelling this way. When/if the art. sinew gets worn, maybe after a few thousand shots, I just cut off the art. sinew (since it is only tied on) and replace it.