In The Eyes of a Tanner - Part 3
In part 1, we learned much about what happens just moments after the animal has been harvested. You now know what is going on inside of body of the animal as it lay there. In part 2, I hope you see the importance of getting the skin off the carcass and freezing it or fleshing and salting the skin or just plain getting it to your taxidermist. If you are a taxidermist, you owe it to your customers to do your part in correctly handling this trophy. Remember, you don’t know what this trophy has gone through before it got to you so make sure you do all you can to “save the patient” so to speak.
I want to emphasize here that primness of the skin and health of the animal will also determine how well the skin/hide will turn out.
In part 3, we will be discussing proteins. Some proteins are tannable, some are not.
So here we go; Part 3
There are many types of proteins found in the makeup of a skin and I’d like to go over those below. These will not be in any certain type of order just a listing I had found.
1-Water: This covers approximately 60%
2-Fats: This is inner fats and is approximately only 2% and does not include surface fat.
3-Salts: Approximately less than 1%
4-Elastin: Approximately less than 1% however, this is protein and can be removed.
5-Albumen: Approximately less than 1% and this is a non-tannable protein.
6-Globulin: Approximately less than 1% and is a non-tannable protein.
7-Mucous Substances: Approximately less than 1% non-tannable protein.
8-Keratin: Approximately 2%-10% and is the makeup of hair, fur, claws, bones and hooves.
9-Collagen: Approximately 30% and is a tannable protein.
In the animal world, collagen is the major insoluble protein in the extracellular matrix and in connective tissue. It is the signal most abundant protein in the animal world. In fact, there are as many as 16 types of collagen. However, 80%-90% of the collagen in the body consists of types I, II and III making up 20%-35% of the whole body content.
Containing as many as 16 types of collagen, they are grouped according to physical structure. Type I is collagen found in the skin, bones, tendons, teeth and scar tissue. Type II is collagen found in cartilage and the clear jelly substance in the eyeball called the vitreous humor. Type III collagen is found in the cells of the skin, muscles, blood vessels and lungs.
Each specific type preforms a different function. The most important overall function of collagen is to strengthen, support and provide elasticity to the skin. Another important function of collagen is to provide support and movement in cartilage tissues such as in the ears, nose, knees and parts of the trachea. Differing amino acid arrangements result in structures such as type I, thick fibrils and fibers, Type II thin fibrils and type III medium sized fibrils.
Collagen is a tannable protein however, in animals from Africa; most of the collagen is shut down and must be addressed during the wetting back process. In fact, this could be the single most important part of the tanning process. In skins that are air dried such as African, I say African because they have a hard time paying someone to crush the rock salt so they can properly rub it into the skins. I’ve had this discussion before and it always seems to fall on deaf ears. Just “CRUSH” the salt please!! Most of the time their response is; “we’ve been doing it this way for forty years.” My response is, “I can tell, the skins coming out of your camp haven’t changed a bit.” It just floors me to see so many varying degrees of quality skins of the trophies your clients have paid hard earned dollars to collect. If nothing else, salt brine the skins then dry them out. At least this way the salt has penetrated completely through the hide. Trapper skins are the same. The collagen is like frozen in time so to speak. Types I, II and III are so compacted on to one another that it will take very specialized chemicals to bring them back to life. Believe me when I say, “It don’t always work.” No matter what we use or what we do, the skins will have to be rejected. It’s just a plain fact and a huge disappointment for all parties involved. One that I strongly feel could be avoided, most of the time. Remember, parts one and two we talked about bacteria and how important it is to stop the growth of it. If the skins coming from other countries or outfitters within the U.S.A. and are not properly handled in the salting stage, and the tannery has a problem getting the skins to spring back to life during the wetting back process, these skins are soaking in a bath of bacteria. We use proven anti bacteria chemicals however, the longer it takes the skins to loosen up, the more risk you take.
Wetting back a life size hippo five years ago may have taken up to seven days to loosen up enough to put into one of our mills. This would cause epidermis loss along with a verity of other problems. However, today it could be as short as three days. So we have come a long way in the application of the chemicals we use and we will always try other products based on the guidance of our chemist to assure our clients have the best chance for a complete return of the trophies their clients harvested.
We cannot remove all the collagen however, during the pickling and shaving process most of it is removed. Our shavers will shave all the nasty, dirty and greasy gunk of off the skin during the first shaving process. This will cause the skin to turn a bluish color. This is how we know we have gone far enough the first time. Then the skins will go into other treatments depending on the species and how well the skins have accepted the pickle the first time. After the skins have gone through these treatments, they will be brought back out to the shaving department for final shaving.
The shaving process is a very important part of a tannery. A tannery can use all of the necessary tools and chemicals at their disposal however, if the shaving is done poorly, the taxidermist will be fighting an uphill battle in getting the skin to stretch and perform properly for him or her. Shaving is something I like to say is a skill you’re born with. Not everyone can do it at the level that is needed in a tannery. This is a skilled trade and most of the time; it takes a good year to have a shaver up to speed on all aspects of shaving.
In the shaving process, the skin is shaved to a thickness or thinness that will allow the tan to penetrate and begin the conversion process. During this process, we remove all of the non-tannable proteins which in turn, give us more tannable surface. Basically protecting all of those nice warm and cuddly tannable proteins so that you will have a skin that will be fully tanned and hold all the detail you, the artist, give the form you intend to put the skin on.
Now, you see the important roll collagen and its friends in the protein world plays in the animal kingdom and just how important it is for you to choose a qualified tannery that knows how to handle and process your skins.
In part 4, I’d like to briefly go over some of the other processes your skins will go through when it arrives here at the tannery. Then, I’d like to start on a series of business talk. My belief is; there is so much information on “How To” mount, finish, paint and make a nice habitat but not so much on how to run a business. I want to focus on helping you become as successful as you want to be.
Until then, I’m Mark Marlette.
