Here is 'basically' how I apply the skins. These instructions are from Paul Brunner. You can use Titebond glue instead of Elmers Carpenter glue if you like, but Elmers works great. And I just spray the bow with Thunderbird. The skin can be 'trimmed' along the limb edges with careful use of a fine file.
SNEAKY SNAKE APPLICATION
1. Here's what you need to get the job done: 2 snake skins, coarse grit sandpaper, 1 pair scissors, 1 sharp hobby knife or scalpel, Elmer's Carpenter's Glue, 1 spray can of gloss varathane. We recommend Flecto brand in the Professional grade (black can).
2. Gently rough up the backs of the limbs of your bow with the coarse grit sandpaper. I use a light
circular motion. This roughs up the surface so the
glue will hold to the limb. I do it light enough, so that if I ever want to go back to original, the limb can be fine sanded back to perfect finish.
3. Get everything ready by having a bucket of water standing by. You are going to put your snake skin in the bucket while you apply glue to one of your bow limbs. Let the skin soak until it is nice and wet and pliable.
4. Using fingers, or small brush, I lightly coat the glue on the limbs, making sure I get complete coverage. Don't get it on too thick. Try not to let it dribble down the sides. It's not a big deal if it does, but makes for more clean up work.
5. Remove the snake skin from water and shake off excess water. Lay the snake skin on the limb. It does not matter whether the head end of the snake is at the tip of the limb or at the riser. The choice is yours, as long as you do it the same on the other limb. I usually have the head end at the
riser. Now start smoothing the skin on. start at the head end of the skin and work it on with your fingers.
6. Keep working any air and glue bubbles out to the sides of the skin, or up to one end. I keep rubbing and smoothing the skin for a couple of minutes.
7. Now you will begin removing the outer scales. This must be done, or your finish will not stick to the skins. Once the skin is beginning to stay in place, I begin using a pocket knife blade (held at 90 degrees to the limb) to remove scales and work out remaining glue and air. YOU MUST GO FROM HEAD TO TAIL WHEN DOING THIS. If you go the wrong way, you will rip the skin. Get as many scales off as you can, but don't expect to get them all off. If you go for all of them, you'll probably damage the skin, although sometimes they come off completely and easily.
8. When I'm through rubbing the skin on, I carefully take a hobby knife or razor blade and trim the excess skin on the sides. I make sure the skin is really sticking in place before I do this. I might move on to the other limb before I trim the first one. Don't try to trim super close at this time, but you don't want a half inch of skin overhanging or it will curl when it dries and lift off the limb.
9. I let the skin dry on the limb for at least 24 hours, then take my hobby knife, which must be razor sharp, and carefully check to make sure the trimming job is perfect...right flush with the bevel on the edge.
10. Now gently scrape any glue off the edges of the limb. I also wipe it several times with a damp sponge until I can find no glue anywhere on the limb. Now check carefully for scales that didn't get removed. I get a good light source and turn the limb every direction. The scales you missed are dull looking compared to the places you removed the others. You can remove the remaining scales two ways. One, you can pop each one with your little finger nail. Two (easier), just lay a strip of masking tape on the limb. Gently peel off (from head to tail, please) and the scales come with it. Now take a new piece and do it again. You're done when there are no more scales stuck to the tape. Gently wipe the skin with a damp sponge and allow to dry for 30 minutes, or so. Now you're ready to spray with Varathane.
11. The spraying does two very important things. It assures that the skin won't lift along the edges when something rubs against it and it gives it a really pretty, protective coating. I use about 5 coats of the Varathane. If the scales are big on the skin, I might use 6. Make sure you get a good coverage, but not so much that the varathane runs down the sides of the limb. Remember, too, that you have to cover the sides, as well as the skin, so that the skin won't lift! The last coat I put on is done from a couple of feet away and is really "over spray". This takes some of the glare and flash off the finish, so that the critters don't see it. You can also cut glare by taking 0000 steel wool (quadruple ought) and gently rubbing the finish.