It may take a week or two for the ammonia in the urine to begin forming. Yes, it smells, but not as bad as a urinal or a public toilet smells. The sources I used for my information had all sorts of interesting lore that went with traditional urine tanning of salmon skin. My favorite was a story about how only the urine of young girls was used. There may be something to all that, since there are different types of hormones and natural chemicals in our urine depending on our age, gender, and health. If you’re the type to experiment, and something tells me those of you still reading just may be, it might be a good idea to sample different urines. Wild animals use urine to mark their territory and send messages to one another, and I can only guess that those odors are present to some extent in our urine as well.
For this I just used my own urine, since I had plenty of it. Preparing the salmon skins is easy. The most important thing one must do with any skinning project is to prevent bad bacteria from colonizing the skin. Start with the freshest fish you can get- caught that day or the day before. Cut the skin off as cleanly from the flesh as possible without cutting through it. Put it in a clean container and make sure not to contaminate it with offal or debris. We were rendering the whole fish for this project, so we just froze the skins immediately in freezer storage bags.
Whatever you do, don’t EVER salt the skins before freezing them, since it prevents them from freezing completely. Next, you take a metal soup spoon and use it to scrape the flesh from the skin. Remove all the fats, flesh, etc down to just the skin. Salmon skin is tough tough stuff, so don’t be delicate here. Don’t worry about the scales, since the urine will take care of those. If you’re tanning another type of skin, say deer skin, then you’ll probably be salting the skin as you remove it from the flesh. You can dry those skins in salt, or you can freeze them for later, but remember to rinse off all the salt before freezing or you could have problems later.
You should have enough liquid to stir the skin and have it float freely. For this skin I used two gallons urine and two gallons water. Make sure to leave a nice note so you don’t surprise anyone if they come poking around your tanning solution. This solution in the tanning world is also called a pickle, FYI. You’ll check the skin every day and give it a stir to keep bacteria from taking hold on any surfaces and get a nice, even finish. You’ll check the skin every day and give it a stir. It should smell a little like fish, a little like hard boiled eggs, a little like ammonia.
It shouldn’t smell too awful, and if it stinks up the place for more than an hour or two when you open the lid, you need fresh solution because bacteria has set in. We use the same pickle for a second set of skins and had problems with bacteria, which tuned the skin pink in one place. Don’t be lazy, change the urine as needed. The skin will change from being really soft and gooey feeling in the pickle to more rubbery like a wet dish glove, with a squeeky feeling when you rub it between your gloved fingers. Feel is important, so get in there and touch it. You’ll also start to see the scales flaking off, and that’s a good sign you’re getting close.
Depending on the temperature, your pickle will take anywhere from ten days to a month or more to cure the skin. Once it’s finished curing, take it out and soap it up with dish soap several times. Lemon scented soap will help cut the scent, but keep in mind that you may develop a negative association with that brand or fragrance in the future. The skin will stink like old pee and dish soap when wet but as it dries that will go away. So will the funk in the room, I promise. The soap will get rid of any remaining oils and salts in the skin and get it ready to dry.
Salmon skin is pretty stuff. The scales may or may not be still attached at this point. You want to lay your skin out in a cool, dry place out of direct sunlight and where no one will mess with it for a while. It will take a few days to dry. For this project we weren’t interested in having the skin completely flat, and if you plan on breaking it for leather then there is no need to stretch it. Just lay it flat on a clean piece of scrap wood while it dries. If you do want completely flat skin, then simply staple the very edges of the skin to the wood with close spacing and without stretching it too much, and as it dries it will shrink on its own. Maria and I really loved the translucency of the salmon skin in its raw form, more as traditional parchment than worked leather. Dried flat like this, light passes through easily and the impression the scales left behind looks lovely. Maria worked with fellow artist Eric Foreman to develop lamps using the salmon to diffuse the light. Skin treated in this way can be rewetted and stretched over a form, and when it dries it will become tight like the skin of a drum.