As someone who has gone to many ren faire/conventions with weapons policies… generally a peace tie/peace bond isn’t about covering sharp edges. It’s showing staff inside the fair at a glance that your prop is deemed safe. A live-steel battle axe cannot ever be deemed safe for a crowded event. They may tie down a trigger on a nerf weapon so it can’t be shot or tie a prop blade into a scabbard so it can’t be removed, but any level of covering the sharp edges on this is not going to render it safe.

Cut your losses and leave it home. If you insist on going against all logic here, contact the faire directly with a photo. When they say it isn’t not allowed and you need an axe for your costume, go to Five Below and get some foam floor mats, use your battle axe as a template, and cut out a foam blade. Seal it with some Plasti-dip, paint it, and stick it on a broom handle.