I stopped this weekend to pick up some food for the dog and some rawhide backings for myself at one of the big pet supply stores. When I got home I realized that I hadn't seen a photo build a long for making hide glue from rawhide in the forum (I thought there was one). I have used dog chews for backing before and usually get decent sized scraps from inside the main bone(hide) this time however it was already ground up for me. If you go this route you can grind your's up with an old coffee grinder if they are not already chopped finely.
1. Get a pot and fill it with water and throw your scraps in(finer sized scraps dissolve quicker). Additionally pre-soaking the rawhide scraps seems to help them dissolve quicker.
2. Turn the heat up until it is gently rolling (do not boil) and let the rawhide start reducing.
3. As it reduces down you may see some of the fat rise to the top in the form of a white froth. This is reduced by scraping additional fat from the hide before boiling. Mine was already pre-ground and I couldn't scrap it. If you see this scoop it out every so often (You’ll remove the bulk of it at the end).
4. Once the rawhide has pretty much dissolved (this can take several days depending on the amount of hide/water) strain it through an old T-shirt or cheesecloth into another container. Heat that container just enough to produce steam.
5. Once the excess water has been steamed away and the glue is about the consistency of a runny syrup increase the heat so you get a strong rolling over (not boiling) then filter it again and pour it into a container to cool.
6. After the solution has gelled up and can be lifted by hand cut it into tiny pieces. Place a fan over it and keep it cool as it dries. Or you may cut it into bigger squares and run some jute through it to hang dry. The final product should look something like this.
