The methods used by regular tanners in making leather are complicated and beyond the resources of men in the woods. Vegetable tanning, with extracts or infusions of bark, etc., requires weeks or even months to complete the process. However, this sort of tanning is adapted mainly to heavy hides. Light skins, such as woodsmen usually handle, are best made into buckskin or else tanned with mineral salts or acids, which are comparatively quick and simple processes.
I will describe a good way to tan a pelt with the fur on. It may also be used to tan naked leather, except that the skin, in that case, is first soaked until the hair will slip and then grained like buckskin, before tanning.
Since one seldom makes a good job of tanning at the first trial, it is best to begin with a skin of little value, and one that is not of a greasy nature— a cat skin, for example, either wild or domestic. The tanning of a furred pelt proceeds in five stages: soaking, fleshing, pickling, washing, and softening:
A skin fresh from the animal needs no soaking, but one that has been dried must be relaxed before anything further can be done with it. Immerse the skin in running water from one to six hours (depending upon temperature, and thickness of skin), or, if this is not convenient, soak it in salted water, using a good handful of salt to the pailful. Take it out as soon as it is pliable, for further soaking would loosen the hair or fur. Then flesh and pickle it at once.
Even if the inside of a pelt has been well fleshed immediately after skinning, still, after it has dried, it will have a tough, glazed surface that must be cut and scraped away, after soaking, to open the pores so that the tanning liquor can penetrate at every point. Do this on a beam, as directed under Buckskin in Chapter XVII. Thick hides must be shaved down uniformly before tanning.
If the skin is greasy, it will not take the tan. To remove grease, rub hot corn meal or sawdust, over the flesh side, being particular not to get it on the fur, as it might be hard to remove; then scrape well. An easier way is to soak the skin for an hour in gasoline, then hang up and dry before pickling.
Dissolve one quart of salt in one gallon of hot water. Let this cool, and then slowly pour into it one fluid ounce of commercial sulphuric acid. Do not inhale the fumes. These are the proportions: the amount, of course, will depend upon the size of skin and vessel used. The latter must not be of metal, but glass or earthenware, or a wooden pail or tub. Soak the skin in this, turning and working it around, once in a while, to ensure that every part gets the benefit of the tanning liquor. A thin skin will be tanned in about two days; a heavy one may take a week. The lower the temperature the slower the action. It will not hurt the pelt to let it stay in the pickle for months: taxidermists use this formula for preserving skins to be mounted at any future time. No, it does not injure hair or fur, but sets it, and discourages attack by moths and other insects.
If you are in a hurry, a stronger solution can be used: water two quarts, salt one pound, sulphuric acid one ounce, which will tan a light skin in about twenty-four hours; but this is likely to "burn" the skin unless you soak it thoroughly in an alkaline solution after taking it from the pickle.
In fact, any skin tanned with an acid should be neutralized with alkali so that no free acid is left in it to cause deterioration. First put the skin on a beam and go over the flesh side with a scraper to press out all the surplus liquid that you can. Then soak it an hour or so in a solution of common washing soda (about a handful to a pail of lukewarm water). Rinse in clear water. Many pelts have been spoiled by omitting this part of the program, and thus the acid tanning has gotten in some quarters, a bad name.
After washing the skin, hang it spread out on a line or frame until half dry. Then work it back and forth (flesh side down, of course) over the edge of a plank or a square bar of iron, and pull and stretch it in every direction with the hands, until it is white, dry, and supple all over. The object is to loosen up the fibers everywhere so that they do not shrink, stick together, and dry hard and stiff. An amateur is more likely to fail here than in any other part of the tanning operation; for it is hard work, and he may not stick to it long enough to ensure a good job.
If still there are hard spots on the skin, moisten them with the pickling liquor and keep them so until softened. A good way is to cover such spots with sawdust wet with all the liquor it will take up.
A final finish can be put on by rubbing with sandpaper or pumice stone.
Then rub into the flesh side a mixture of equal parts of tallow and neat's foot oil, or some butter, or lard, or vaseline, or (sparingly) with plain oil or viscol. Do not use a vegetable oil. To remove any surplus, so that the skin may not be left greasy, rub hot corn meal or sawdust over it.
Finally, comb out the fur, and the pelt is ready for making up into a rug or garment.
There are many other ways of "mineral tanning" but the one here given is less complicated than most of them, as satisfactory as any, and is adapted to any kind of skin, big or little, with or without the haii* or fur. Tanning with alum I do not recommend: it shrinks and thickens the skin, hardens it, and makes the fur dull and harsh if any gets on it.
One may be so situated that he can get none of the ingredients required by the above process, and still he may want to make a robe with the fur on. In such case, do as the Indians did, who had not even salt. A pelt can be "Indian-tanned" as soft as by any chemical process, and will be even stronger and more durable. The only trouble is that it takes more elbow-grease.