Most of the defects of raw materials arise from violation of the rules for the primary processing, conservation or storage of skins. In some cases, a violation of the conservation technology can lead to irreparable defects that make it impossible to manufacture a semi-finished product or reduce the quality of the finished product.
So that you are not foisted on a batch of defective raw materials, you need to be able to identify possible defects and know how much a particular defect can affect during further processing. We will talk a little lower about the methods of eliminating the defects obtained during conservation and how to find out these defects, but for now we will tell you how to properly preserve and store the skins.
First of all, you should take care in advance that the skins are not contaminated - adhered feces (bulk) spoil the hairline, complicate the ritual and not only serve as an excellent breeding ground for the reproduction of putrefactive bacteria, but also, being not completely removed during the processing, prevent penetration deep into the skin preservative solution. The result is poor-quality preservation, even if all norms are observed (terms, material consumption, etc.).
Contaminated raw materials have to be additionally harvested to free them from the bulk, and this takes extra time, effort and complicates the manufacturing process, while the complete removal of the bulk from sheep skins without a special tool - an electric plane - is generally impossible, since it can lead to the formation of bald patches. That is why it is so important to keep animals before slaughter for 3 hours without water and up to one day without food. The recommended norms for pre-slaughter aging without food are for fur animals and rabbits - 16-18 hours, for sheep, goats and cattle - 22-24 hours, and for pigs - about 12 hours.
The removed skin must cool before fleshing, this is necessary both to facilitate fleshing and to create the best conditions for subsequent canning. At the same time, cooling for more than an hour and a half is not recommended, otherwise no preservation will cope with microorganisms rapidly multiplying in the skinned skin.
Remaining on the skin tissue, the flesh, cut meat and lard make it difficult to preserve and can reduce its effectiveness. Therefore, they must be completely removed, which is very difficult if the cooled skin has folds and folds - in this case, with excessive zeal, the dermis itself can be easily damaged. To prevent this from happening, the steamy skin is carefully straightened. The skins of fur animals and rabbits, taken off with a "stocking", are turned inside out with fur and tightly stuffed with straw or pulled onto a wooden disc (Fig. 6), on which they then flesh. Small skins, removed from the cavity, are straightened with the flesh side up on a rule board and fixed along the contour with pegs.
Figure: 6. Straightening small skins for fleshing
The ritual of large leather raw materials is facilitated by the use of special tools and devices. It is more convenient to knock down the bulk and other contaminants with a dead end knife on the deck: the skin is laid out with the hair side out and the head part up, the working stroke of the dead end is only in the direction of hair growth (that is, from top to bottom). If necessary, the rituals of the outer side of the skin, begin with it and only then move to the inner side. As a tool for scraping the flesh side, you can use an arc knife, a scythe blade (of course, wrapping the sharp end with a piece of matting, tarpaulin, etc.).
Fleshing of sheepskins and goats is carried out on the table, large skins are removed from the cut on a special inclined deck (Fig. 7). The remnants of muscle tissue are driven from the rump to the head, and on the floors - from the ridge to the womb.
Figure: 7. Tools and devices to facilitate the ceremony:
a - a deck upholstered in galvanized sheet; b - a dead-end knife for driving the bulk; c - "safe" braid.
The ceremony is considered to be of sufficient quality if a layer of subcutaneous tissue with a thickness of no more than 3 mm is preserved on the inner side of the skin, the hairline does not have traces of heap and other contamination, and there are no traces of unskilled removal on the skin (ear cartilage, tail replicas, etc.).
There are several methods of conservation, each of them has its own characteristics and its own scope. All skins can be preserved in one of the ways - fresh-dry, dry-salted or wet-salted (brine and dry salted in gratin). To preserve fur, rabbit skins, fur and fur sheepskins, the acid-salt method is also used. The choice of one or another method of conservation is determined by the type of raw material, as well as specific conditions. In addition to observing the conservation technology, it is necessary to ensure that exactly the method is used that is suitable for the given raw material.
Fresh-dry preservation method... This method is the simplest and, despite this, hiring her is preferable. It is used only if for some reason (forced slaughter under unsuitable conditions for distant pasture farming, etc.) normal canning is impossible. In essence, this method is drying the skins without any pre-treatment with preservatives. Due to its low efficiency, it is unsuitable for any long-term storage of raw materials, it is not recommended for skins with thick leather tissue.
Drying should be carried out in warm, calm weather - the wind combined with low humidity can lead to overdrying of the outer layers of the skin tissue, which shrink into a crust and prevent moisture from evaporating from the deep layers of the dermis.
Drying is carried out indoors or under a canopy, hanging the straightened skins on smooth poles (not on a rope or on a wire!) With the flesh side out. Periodically, you should lower the skins a little on both sides so that the fold line does not remain undry. Paws, crank and floors should be protected from twisting, for which they are opened (sawn) with wooden planks. The poles with skins hung on them should be located no closer than 20-30 cm from each other.
Drying of sheepskins is allowed and the goat has grown in the open air, in this case, they need to be turned over from time to time and not to be allowed to stay in direct sunlight for a long time. A well-dried hide should have completely dry hair and a dense, non-watery skin tissue.
Such raw materials are stored in stacks, sprinkled with naphthalene to protect the scalp from moths (15-20 g of naphthalene crystals for large skin and 3-5 g for small skin). The maximum storage temperature is 30 ° C at a relative humidity of not more than 70%. The latter requirement is especially important, since dry skin easily absorbs moisture from the air, which can lead to dampness and bacterial decomposition.
Longer storage and protection from moths and leathery stuff ensures the complex use of chemicals: the rack on which the skins will be laid is sprinkled with a mixture of naphthalene, sodium fluorosilicate and paradichlorobenzene (respectively 2; 0.5 and 2% of the mass of the skins). Laying the skins one on top of the other, each is sprinkled with this mixture.
Dry-salted preservation method... It differs from fresh drying by preliminary salting of skins, but it is still considered not the most reliable: since a relatively small amount of salt is used for dry salting, complete replacement of moisture with saline does not occur, and raw materials must be dried to prevent possible decay. At the same time, this method is often used, especially for preserving large batches of skins in the summer and in areas with hot climates - both for reasons of economy and because of the relative simplicity of the method.
The skins are salted, spreading the skin upwards, on a special platform - a wooden shield of a rounded profile (Fig. 8). The surface of the platform is pre-sprinkled with a centimeter layer of salt, the first skin is laid and sprinkled with salt at the rate of 20% of the mass (that is, 200 g of salt for each kilogram of the paired skin mass). Areas from which the cuts have not been completely removed are additionally rubbed with salt.
Figure: 8. Platform for salting in the spread
A second skin is laid on top of the first, also with the skin upwards, covered with salt, etc. The most common mistake with this method of conservation is the skins not selected in advance by size or weight; non-standard skins with a large area, as a rule, are not weighed, and they have the same amount of salt as was measured for smaller skins. In the best case, the amount of salt is increased by eye, and if the percentage is not observed, the skin of a larger mass may simply not be salted.
If there are enough skins to lay out a full pile (1.5 m high for large skins and 1 m - for sheepskins and goats), then the skins are stacked "sprawling", that is, each next one is slightly shifted relative to the previous one so that the pile remains vertical ... After finishing the laying, the pile is sprinkled with salt and kept for at least 3 days for large skins and at least 2 for sheepskins and goats.
For salting, table salt is used: grinding No. 3 for large skins with dense leather fabric, grinding No. 2 - for skins of calves, pigs, etc., and grinding No. 1 - for sheepskins and goats. Do not use salt that has already been used twice, since it contains a high content of salt-loving bacteria. Salted skins are carefully cleaned of salt residues and hung out to dry in the same way as described for the previous method of conservation.
Dry-salted raw materials are stored in the same way as the raw materials of the fresh-dry method of conservation, the consumption of antiseptics for the preservative mixture is halved. Skins dried in the course of dry salting or pre-dry canning require careful attention to themselves, since the skin tissue that has lost its plasticity easily breaks when bent. The high degree of hygroscopicity makes the raw material quite vulnerable - when the air humidity rises, it begins to soak.
Canning with dry salted vrasstil... This method is also called wet salting, and there is no mistake - it is “dry” only in comparison with brine (see below), and it is called “wet salted” because, unlike the methods of conservation described above, this method does not involve drying, and the raw material sufficiently retains the elasticity of the leather tissue (by the way, this greatly simplifies the subsequent processing). Among the other advantages of dry salted vrasstil can be called the simplicity of the method and the fact that wet salted raw materials are not afraid of high humidity during storage.
The lack of drying in the wet salting process is compensated by an increase in the salt consumption rate up to 400 g per kilogram of fresh skin weight. For sheepskins, the amount of salt increases to 0.5 kg. The rest of the salting is carried out as in the case of dry salting, except that the skins in a pile can withstand longer: pork and other large skins - at least 7 days, sheepskins and goats - 4-5 days.
The described method involves the use of chemical antiseptics, which complement the effect of salt and ensure reliable preservation of raw materials. The chemicals are thoroughly mixed with salt, and the skins are already filled with this mixture. Depending on the type of raw material, it is possible to use one of the named antiseptics (in grams per kilogram of steam skin weight):
- Sheepskin; naphthalene - 10 g per kilogram of fresh weight, skins, or paradichlorobenzene - 5 g, or sodium fluorosilicate - 12.5 g.
- Opoek, outgrowth: naphthalene - 8 g, or soda ash - 10 g, or paradichlorobenzene - 4 g.
- Large leather raw materials: naphthalene - 8 g or paradichlorobenzene - 4 g, or sodium fluorosilicate - 10 g, or ammonium fluorosilicate - 6 g.
In order to avoid reddening of the flesh, preservation should be carried out at a temperature not exceeding 20 ° C. For a small amount of skins, batch salting is allowed (Fig. 9), when individual skins after salting in a stack (2-3 days) are additionally salted and folded into a bag, as shown in the figure.
Figure: 9. Batch salting of individual skins.
Folding each section, the hairline is sprinkled with a mixture of salt with one of the following chemicals (grams per kilogram of pair weight): naphthalene - 1 g, or paradichlorobenzene - 0.5 g, or sodium silicofluoride - 1.2 g, or ammonium silicofluoride -1, 2 g
The skins rolled up in bags are kept for up to 5 days, turning from time to time for even salting. So that the brine does not stagnate in the packages, they are placed on the same platform with their ends to the sides - then the brine will drain without obstacles. Often, raw materials are delivered in the form of packages; when purchasing packaged skins, you need to know that the average shelf life from the moment of salting is no more than ten days.
Longer storage of wet-salted raw materials is ensured by stacking in the stacks; sprinkling with a preservative mixture, the skins are laid down with the hairline so that for every forty to fifty centimeters of height, one row of skins hangs outside the pile, like aprons. Having laid out the next few rows, they are covered with the protruding edges of the skins, bending the last top (a method of farthing). As a result of this method of stacking, the raw material is less exposed to air and does not dry out when the temperature rises. In general, wet-salted raw materials do not tolerate either high temperatures (optimal for it - 15-20 ° C), nor too dry air (stored at a relative humidity of 70 to 80%).
The low storage temperature is also good because it allows you to notice in time an increase in temperature inside the stack in case of bacterial decomposition processes; To control the temperature, a wooden (not iron!) gutter is placed in the stack during its laying, an ordinary thermometer or alcohol thermometer is left in it, and the end of the gutter protruding outward is plugged with tow or matting. In the case of a steady increase in temperature by 5-6 ° C compared to the temperature in the room, it is noted that decay is taking place in the stack - it is possible that bacterial or simply poor-quality salted raw materials got into it when it was laid. To preserve the rest of the skins, the stack is disassembled, the raw materials are dried and additionally sprinkled with a mixture of antiseptics.
Tuzlukovanie... Preservation in brine is the most effective way to preserve skins, which requires special containers. It is used for skins of cattle, horse and pork, as well as calf and outgrowth. Provides uniform salting of the entire area of \u200b\u200braw materials. Brine treatment, like the methods described above, requires accurate weighing of the hides in order to most accurately determine the volume of brine and the amount of chemicals.
The skins should be weighed before washing (preparatory operation before brining). Washing is carried out on a table with a convex surface: the skin is spread with the hair side up and not hot (up to 20 ° C) water is washed, driving off excess moisture. You can use a rounded-tooth scraper to remove dirt. To avoid oversaturation of fabrics with water, washing should not be delayed longer than 2-3 minutes, after which the skin should be allowed to dry for an hour.
For one kilogram of the mass of a pair of skins, 3 liters of a saturated solution of table salt are consumed (recall that a saturated solution is considered when the salt stops dissolving - this requires about 320-350 g of salt per liter of water). To preserve large and pork skins, one of the following antiseptics is added to the saline solution: sodium fluorosilicate - 2.4 g per kilogram of pair weight or the same amount of ammonium fluorosilicate (they are dissolved separately and poured into the saline solution with stirring).
Pork skins are kept in a preservative solution for 15 hours, for the rest, the duration of brining is from 20 hours (for the largest) to 10 (for small ones).
After brining the skins are laid out on the brine moaning platform; after two to three hours, they are additionally added with a mixture of salt (150 g per kilogram of paired skin weight) with one of the antiseptics: naphthalene - 3 g per kilogram of paired weight, or paradichlorobenzene - 1.5 g, or sodium silicofluoride - 3.8 g. or fluorosilicate ammonium - 3.8 g. Then the skins are left in a stack for 2-3 days to complete the conservation process.
Note: fur and small leather raw materials (calyces, outgrowths, etc.) are not treated with fluorosilicon chemicals; for salting such raw materials, only naphthalene or paradichlorobenzene can be used - 3 g and 1.5 g, respectively, per kilogram of the weight of the fresh skin.
The room in which the finished raw materials are stored must have drainage grooves or cement screed along the floor with a slope to the drain hole so that the brine flowing from the skins is drained away from the stack by gravity. In hot weather, to avoid overdrying the skins, place buckets of water next to the stack or cover the stack with sacking moistened with saline.
Acid-salt canning... This method is the most preferable for fur-coat raw materials, since it provides the best preservation of the connection of the hair coat with the leather tissue and makes the raw material less susceptible to increased air humidity.
Fur or rabbit skins, provided that they are not going to be made immediately, after fleshing are dried for 30-40 minutes and a solution of sodium chloride with alum powder in a 1: 1 ratio is applied with a swab (soft brush) to the flesh side of the leather tissue. rub evenly over the entire surface of the bakhtarma; it is more convenient to do this without removing the skin from the rule or mold, on which fleshing was carried out (Fig. 6). On the rules, the skins are dried.
Larger raw materials, such as fur or fur sheepskins, are treated with a mixture of a somewhat more complex composition: table salt of grinding No. 2, ammonium chloride and aluminum alum (85; 7.5 and 7.5%, respectively). The mixture is thoroughly mixed and rubbed into the fleshy side of the skin straightened on the desktop, then the skins are stacked (see "Canning with dry salting"), evenly filling each with the same composition as the treatment was carried out. The skins are kept in a stack for at least a week.
Store raw materials in a cool room with limited access to direct sunlight. The skins removed with the "stocking", after drying, are turned inside out with the fur and kept hanging. The skins, removed from the cavity, are sprinkled with mothballs and stacked in pairs, hair to hair.
The hairline of raw materials, which is stored for a long time, should be periodically inspected for ovaries formed by moths. Having found a bundle of stuck fur in the form of a thin plait, it is necessary to carefully examine all the rest of the raw materials, and comb through the discovered ovaries until the damaged hair is completely removed.
I was always sorry to throw away the skins of slaughtered kids. At one time, I even greased the skins, hoping to soon learn how to make them. However, all the methods found were quite time consuming and required substances that were difficult to obtain. In the end, my patience ran out and through my acquaintances I found a person who knows how to make skins. Fortunately, I first decided to try an easier way of dressing.
1st method.
Skinning.
Lay it out on a flat surface in the shade with the fur down.
Wait until it cools down.
Sprinkle baking soda on the inside liberally. Soda should not be spared. For 1m ^ 2 you need somewhere 4kg. Soda weight is approximate.
Wait until the skin is dry. This takes at least 1 day, or even more. It is advisable to stir the soda for better drying.
After drying, shake off the soda. The skin is ready for long storage. I stored the skins in this way for over 3 months.
It doesn't matter if you kept the hide or not, you can move on to finishing.
Take warm water into the container and add more washing powder than usual. The water should be very soapy. Also add furacilin.
Dip the skin there. Stir occasionally. Wait until the skin is soft. This happens quickly enough.
Erase the skin. If the water is heavily contaminated, change it and repeat.
Rinse the skin after washing.
Pull the skin with nails on a flat surface.
When it is dry, but not dry, grease the inner surface with a spindle.
After drying, the skin is ready for use.
Skins dressed in this way have been used for more than a year. Wool smells fresh (washing powder), soft. BUT! the skin itself is tough. Suitable for rugs. When raw, you can put it on a curved surface; after drying, the skin retains its shape.
The ease of the method compensates for the disadvantages. The first drawback is the toughness of the skin. The second no less important drawback (I did not check it, but theoretically it should be so) sensitivity to moisture. That is, I do not recommend sewing clothes from such a skin.
I don't know an easier way to make a skin.
The area of \u200b\u200bapplication of hard skins is quite limited. So it was necessary to figure out how to make the skin soft.
The second way is an extension of the first way.
Three stages are added to the above method: fleshing, iron brush, pulling.
It is advisable to flesh the skin after removal. That is, clean the inner surface of cut meat and fat. It is best to do this with a special tool, but it is quite possible to do with a knife. It is possible, but not very convenient.
If you want to keep this step to a minimum, you need to be very careful when skinning. BTW, I tested the skinning method with a pump. I will definitely take a picture when I do this.
Further as usual. Fall asleep with soda. Dry. You erase.
After washing, wring out the skin and place it on a flat surface. With the help of nails, pull it. Leave to dry. When the hide is dry but not dry, use a wire brush to brush the inside surface. This should be done without fanaticism. Lubricate with oil. Leave to dry.
Further, the torment begins, much greater than with flesh. The skin must be fingered periodically. That is, you remove the skin from drying. And you rub it with your hands, make movements, as in a hand wash. Knead the skin in this way carefully. In addition to "washing" the skin needs to be stretched in different directions. Fingering is a very tedious activity.
So you've mashed the skin. After that, lay it down again on a flat surface and fasten it with nails again. After a while, repeat the pulling and so on until it dries completely. This is tiring, but the result is that after the skin is dry, it will be quite soft. The degree of softness is determined by your efforts while pulling.
Such processing makes the hide softer, but still, I believe that the hide will be afraid of dampness. So it's not good for clothes.
Unfortunately, I have not experienced such a skin in a year. So I cannot confirm the durability experimentally. But given that the second method is no different from the first, the forecast is favorable.
Making skins at home
It is a sin to throw away the skin removed from the carcass of a killed animal, be it a trophy of a successful hunt, a domestic goat, sheep or nutria. Get to know the cheap and easy skinning method that I believe is available to everyone. I use it to dress sheep, deer, marmots, rabbits and goats. But the method is suitable for dressing the skins of all mammals, especially if you want to preserve the fur. After such dressing, the skin becomes soft and easy to use, for example, for making things that require cutting and sewing.
Sprinkle salt on raw hides
The raw skin, just removed from the carcass, must be cooled, after removing the remaining meat and fat from its inner side. For cooling, the hide is spread in the shade on a completely flat surface, for example, on a concrete or stone floor, with the wool down.
When you feel that the skin has cooled down, immediately add non-iodized edible salt to the inside (skin) of the skin. To process sheep or deer hide, you will need 1.5 to 2.5 kg of salt. If the skins are not salted immediately after skinning, they will disappear. The decomposition process will begin, and during further processing the skins will lose their fur.
The skin should lie on a flat surface, its edges should not curl. When dragging the skin, do not stretch it. If part of the salt falls off the surface of the flesh, add it without skimping. The salt should absorb moisture so that the skin is completely dry and crunchy. The process can take from several days to a couple of weeks. The completely dried skin retains both its shape and quality well.
What is required for making skins
If you are ready to start dressing skins, prepare everything you need in advance:
26.5 l of water,
1 kg (16 cups) flaked bran
16 cups of regular non-iodized salt
2 large plastic vats with a capacity of 114 l and 1 lid,
1 wooden stick 1.2 m long for stirring the mortar and turning the skins,
3.5 cups of acid for car batteries,
2 packs of baking soda
Wooden lattice or flooring for stretching the skins,
Hoof oil,
Metal brush.
The indicated quantities are calculated for the manufacture of four skins of large animals, or 10 rabbit skins, or 6 skins of medium-sized animals, for example, marmots. To make fewer skins, adjust the numbers shown.
Solution for dressing skins
A few hours before you plan to start dressing, dry skins should be immersed in fresh, clear water and soaked until they become elastic.
Boil 11.5 liters of water and pour over the bran. An hour later, when the flakes are well steamed, fold them onto a sieve to strain the brownish infusion. Bring the remaining 15 liters of water to a boil. Pour 16 cups of salt into a plastic tub, pour boiling water over and stir well with a wooden stick until the salt is completely dissolved. Pour the brownish bran infusion into salt water and stir the resulting liquid.
When the liquid has cooled and becomes lukewarm, add car battery acid to it. Observe the precautions indicated on the acid bottle label. Wear old gloves and a long-sleeved shirt when handling acid. Pour out the acid carefully, holding the bottle just above the surface of the solution and do not allow it to splash. Stir the mixture well.
Now you can start cleaning the dry skin. When dressing fresh hides, this procedure can be omitted. Submerge the skins in the solution and stir. The skins must be completely covered in liquid in order to be thoroughly saturated with it. The skins should be kept in the solution for about 40 minutes, stirring occasionally with a stick to evenly soak.
Fill the second plastic vat with clean warm water and proceed to rinse the skins. Take all the skins out of the solution one by one, using a wooden stick, and place them in a container with clean water - you need to wash off the excess salt from the skins. To wash the skins better, they need to be stirred and patted with a stick for 5 minutes, and when the water becomes dirty, change it to clean.
Some people add baking soda to the rinse water to neutralize acid residues in the hide. This allows people with sensitive skin to be insured against possible irritation. But on the other hand, this neutralizes the acid, which was used precisely to preserve the skin. Therefore, before pouring the baking soda into the rinsing vat of the tanned hides, decide for what purpose you will use them. If it is assumed that the skin or fur will come into contact with human skin, then you need to rinse it in water with soda. And if the skin is thrown on the floor like a carpet, or hung on the wall, then in my opinion, you can not add soda when rinsing.
The washed skins should be hung on a stable and sturdy crossbar to drain the water. Then soak a sponge, rag or brush with hoof oil and apply the oil to the still wet flesh. To do this, you need 30 g of hoof oil. It is very quickly absorbed into the skin, leaving only a light oily coating.
Now the skin needs to be pulled over a wooden grate or flooring. While nailing the skin to the deck, gently stretch it so that the tension on the skin is felt, but not too tight. Transfer the skinned flooring to the shade to dry.
Do not pour out the acidic solution remaining after tanning without neutralizing. Two packs of baking soda are enough to neutralize the acid. During the reaction, the solution will begin to foam heavily and release toxic gas. Therefore, it is best to do this in a well-ventilated room and stay away from the vat. Do not pour solution near drain.
The skins should be checked daily during the drying period. When the center flesh feels dry, supple and soft to the touch, remove the skin from the deck, spread the fur down and brush over the flesh with a wire brush. Thanks to this procedure, the hide becomes softer and lighter. Avoid brushing too hard or rubbing any one area of \u200b\u200bthe hide. Just try to give the flesh a suede look. After that, the skin needs to be hung for a couple of days for final drying.
One last tip
Once your friends find out that you know how to make skins, be prepared for the fact that you will not have an end to those who want to use your abilities. If you can't refuse such a service to your friends, then at least don't do it for free. Industrial leather dressing costs between $ 25 and $ 45 a piece, and the cost of your service should be adequate, even if the money received is just enough for a case of beer. Otherwise, the hunters will drag you all their trophies, overwhelm you with work and deprive you of the opportunity to do other things.
It is possible that someone will use the services of professionals to find out what mistakes you made, or how much your service might result in. People really appreciate their own hides, and this warning will help you avoid misunderstandings and maintain good relations with your friends.
There are many ways to make skins. I will try to outline the most accessible and proven ones. The process of dressing skins takes place according to the following scheme: soaking - washing - fleshing and degreasing - pickling or pickling - tanning - drying - finishing.
Before dressing, inspect the skin, if the skin is contaminated with resin, remove it (resin, of course) with alcohol.
Otmoka - the process of soaking skins treated with a fresh dry method. It is produced in a solution of table salt, the concentration is grams per liter of water. The amount of the solution should be such that there is a layer of water of 2 - 3 cm above the skin.In order that microbes do not develop in the solution, an antiseptic is added - zinc chloride (2 g / l), formalin (0.5 - 1 ml / l) , 1 - 2 tablets of furacilin. You can add a little washing powder to the solution when soaking. If the skin does not get wet within 12 hours, the solution must be changed. Soak until nose and paws are softened.
the washing up... Wash the skin in a warm (not hot) solution of washing powder. Some recipes recommend a "squeaky hair" wash. When washing, it is necessary to wash the skin from the sand, wash off the smell of doggy from the fur. This is especially important for foxes and raccoons. During washing, the skin is partially degreased, therefore washing can be done after fleshing / degreasing. After washing, the skin is wrung out, the skin is wiped with a dry cloth.
Fainting - the skin is scraped with a blunt knife in the direction from the tail to the head, pulling it over the board. It is good to make a special convex board from a slab of hardwood. The purpose of fleshing is to remove residual fat, film, and meat. If the initial processing has been done well, then fleshing will be easier, so don't be lazy to process your trophy well. But do not get carried away so as not to expose the hair roots.
Pickling - This is a classic way of dressing skins, providing a higher quality of dressing, greater strength of the leather. And the disadvantages are the duration of processing, an unpleasant smell. The recipe is as follows: 200 g of coarse oatmeal or rye flour is stirred in 1 liter. hot water, add g. salt and 7 g of yeast, 0.5 g of soda. When the solution has cooled, the skin is immersed in it. Duration of fermentation - 2 days. The solution must be stirred periodically so that a film does not form on top and the solution does not rot.
Picking (acid treatment) is used instead of fermentation. The composition of the pickel (per 1 liter of solution): 60 ml of 70% acetic acid, 30 g of salt. You will get a strong pick (4.2%). A stronger pickle will destroy the skin, so it is better to make a 3% pickel - 43 ml of 70% vinegar essence per liter of water. Salt is required. You can use sulfuric acid (2.5 - 5 g / l), but mineral acids reduce the strength of the product, I do not recommend this method. Picking lasts from several hours to two days, depending on the thickness of the skin, the quality of degreasing, etc., and it is better to underexpose than to overexpose the skin in a pickel. The end of pickling is determined by the "dry" and "pinch" test. The test for "drying" is done as follows: the skin is taken out of the solution, near the groin, the flesh is bent four times upward, the corner is tightly squeezed and the bend is carried out with a fingernail. If the skin is ripe, a white strip will remain on the fold for some time - "drying". The pinch test is easier: hairs are plucked out in the groin area, if this is done easily, the skin is ready. Another sign of the ripeness of the skin is that the inner layer of the skin is easily peeled off with your fingers. After the end of pickling, the skin is slightly wrung out, folded in half with the fur up and placed under a small load. The crawl lasts for hours. Since acid remains on the skin, the skin is placed in a solution of baking soda 1-1.5 g / l for 20 minutes. I do not do this.
After pickling, the skin is dried on a rule. First it is dried with the flesh up, then the fur up. Remove excess solution with a rag, while drying, straighten the fur by shaking the skin. Finally dry the skin up, but if it is overdried and the skin cannot be turned out, do not break it, leave it like that, you will still wet the skin anyway. Or you may not finish drying.
Tanning - performed in a solution of chromium alum (potassium alum can only be used in a mixture with chromic alum), 2 - 3% carbolic acid, or in a decoction of oak or willow bark. I use a decoction of willow bark, because alum has to be obtained, phenol (carbolic acid) smells unpleasant, and is harmful, oak coarsens the skins too much, and willow is always at hand and stains the skin a pleasant creamy color. Pull bark from willow trees that have fluffy leaves. The willow is also suitable. Fill a saucepan with bark (tight, but not ramming). Fill with water and boil for half an hour, then drain the solution, add 1 liter of salt, cool. Since the solution also stains the fur, I do not soak the skin in it, but soak the skin, repeatedly applying the solution with a brush. The skin must be saturated with tanning agent. After that, the skin is folded with the skin inside and left for a day to lie down. Then the skin is dried. This is where we need to work. The skin will have to be dried almost by hand. As it dries, the skin is removed from the rule, crumpled, stretched in different directions. It is necessary to catch the moment when the skin is semi-dry; it will turn white when stretched and become “suede” to the touch. Paws and muzzle are stretched across. After drying, the flesh can be carefully sanded with sandpaper. Now the skin has become soft.
To increase its water resistance and softness, fattening is performed. You can soak the skin with a mixture of glycerin and egg yolk 1: 1, or with this solution: dissolve 50 g of soap in 0.5 liters of boiling water and add 0.5 kg of fat (pork, fish, etc.), add 10 g of ammonia alcohol. You can replace part of the fat with glycerin, part with yolk, and a small part with machine oil (up to 5%). The mixture is smeared with the skin and allowed to rest for several hours. Then the skin is dried, kneaded, the fur is combed, the flesh can be rubbed with chalk, it will absorb excess fat and the flesh will be light. Thick places can be rubbed with sandpaper, just don't get carried away! This is where the torment ends, the skin is ready.
After the slaughter of farm animals, the question arises of how to deal with the skins. Leather and fur are hot commodities on the market, so it is not rational to just throw them away, and handing them over for processing to specialized enterprises is not always profitable from an economic point of view.
You can make skins at home. True, the manufacturing process is quite lengthy and includes the following stages: soaking, fleshing, degreasing, pickling, tanning and fattening.
Leather dressing involves working with various chemicals, including acids and alkalis, and requires strict adherence to safety precautions. Deviation from the rules can, firstly, spoil the skins made, and secondly, harm your health.
If you are dealing with freshly skinned hides, they must be cooled and salted before dressing. With the help of a knife or scraper, the remaining fat and meat are removed from the inside (flesh) of the freshly removed skin. Spread the peeled hide with the fur down on a flat, level surface such as a concrete floor. In order for the skin to cool faster, the sun's rays should not fall on it.
When the skin becomes cool to the touch, its flesh is sprinkled with edible non-iodized salt, which absorbs moisture, thereby preventing skin decomposition and fur loss. The processing of goat or sheep skins takes from 1.5 to 2.5 kg of salt. For hides of smaller animals, adjustments should be made accordingly.
It is important that the entire flesh is evenly coated with salt. If, when moving the skin, part of the salt crumbled, the bare areas must be sprinkled again. The skin covered with salt is laid out on a flat surface, while its edges should not be bent, but it should not be stretched either: this will cause the product to lose its strength. Depending on the thickness of the skin, salting can take from a few days to 2 weeks.
Dry skin can be dressed. Moreover, you must prepare in advance equipment and substances for all stages of dressing, so that when the time comes for the next operation, it does not have to be postponed due to the lack of one or another chemical. Hitching will not have the best effect on the quality of the final product.
On the Internet and in specialized literature, you will find a large number of different methods of dressing skins: from methods that almost exactly repeat industrial dressing technology, to amateur recipes developed through experiments and based on personal experience. However, any of the proposed methods would involve a sequence of standard skinning steps. The chemicals used and the time allotted for each procedure will differ. We do not see the point in phasing out the many existing recipes. Instead, we present some generalization of the methods of each stage of dressing, listing the possible options for its implementation. Dried skin loses its elasticity. To restore its ability to interact with chemicals, the skin is softened by soaking it in water with antiseptics and table salt.
Soak
Remember the general rule of carrying out all procedures related to immersion of skins in water: liquid must be poured so that the skins can be easily mixed in it, that is, not too much, otherwise the water will splash out, but not too little, otherwise all the liquid will be absorbed into the lower layers, without moisturizing the upper ones properly. For 1 liter of water, 40-50 g of table non-iodized salt and any antiseptic substance are diluted: 0.5-1 ml of formalin; 1 g sodium fluorosilicon; 2 g zinc chloride; 2 g sodium bisulfite; 1-2 tablets of norsulfazole, sulfidine or furacillin. For 1 liter of water, you can also dilute a mixture of 1 g of zinc chloride or sodium silicofluoride and 1 g of sodium bisulfite. For soaking thick skins, it is recommended to add 2 g of washing powder to antiseptics. Soaking water should be at room temperature, that is, at 18-20 ° C; if it is above 25 ° C, this will lead to the loss of fur. Soaking takes several hours. If, after 12 hours in water, the skin is still not sufficiently soft, the solution is replaced with fresh one. A well-soaked skin is soft over the entire surface, there should be no hard areas on it.
SINCE
The soaked skin is laid out on a flat, even surface (board or deck), the remaining fat and films are straightened and scraped off the flesh.
The tool is a scraper or a dull knife. If during the initial processing the skin was well cleaned, fleshing will not take much time.
DEGREASING
No matter how thoroughly the primary treatment and fleshing are carried out, subcutaneous fat will definitely remain, and it seems possible to remove it only with the help of chemicals. To process thin, non-greasy skins, use laundry soap dissolved in warm water (18-20 ° C). A more universal way is to treat the flesh with washing powder (3.5 g per 1 liter of warm water). To degrease skins with a particularly thick fat layer, surfactants are used: sulfanols NP-1, NP-9 or Santamide-5. 3.5 g of one of these chemicals are dissolved in 1 liter of water at a temperature of 30-35 ° C. Surfactants can be replaced with a mixture of 8-12 g of soda ash and 2-3 ml of oleic acid. The skins are poured with one of the compositions described and gently stirred for 30 minutes. After degreasing, the skins are washed in running water, squeezed or beat off the fur with a stick, then wiped the skin with a clean cloth, eliminating excess liquid.
PICKELING
Pickling (from the English pickle - "pickle") - the process of processing the skins with acid. Sulfuric acid is used in industry; at home, it is replaced with acetic acid.
The 3% vinegar pickel is versatile, which copes with the task regardless of the type of raw material. To obtain it, 42 ml of 70% vinegar essence or 250 ml of 12% or 330 ml of 9% is diluted with water to a volume of 1 liter, after which 30-40 g of salt is dissolved in this composition.
Picking takes from 5 to 12 hours. The readiness of the skin is determined as follows: it is slightly squeezed out, folded in four, strongly squeezed at the fold and immediately straightened the skin. If there is some dryness on the fold (white strip), pickling is complete. Initially, due to a lack of experience, it will be difficult for you to recognize the dry, so start checking the skin even when it is probably not ready. Each time the dryer will show through more and more. A sharp, distinct drying will indicate that it is time to remove the skin from the pickel.
If the skin is intended for sewing clothes or other products that will be in direct contact with human skin, it is advisable to neutralize the pickle with a solution of baking soda (1-1.5 g per 1 l of water) or photographic hyposulfite (10 g per 1 l of water). The skin is kept in a neutralizer for 20-60 minutes. This reduces the firmness of the skin, but the risk of an allergic reaction decreases. In other cases (for example, if the skin is made for the manufacture of carpet), you can confine yourself to washing the raw materials with running water.
Pickling is sometimes replaced by pickling. This is a more complex, but at the same time, more effective procedure. It is carried out with various mixtures, which include coarse rye or oat flour or oatmeal, ground in a meat grinder.
The skins are fermented at a water temperature of 37-40 ° C for 2-5 days. For 1 kg of raw materials, about 3 liters of kvass are consumed. The readiness of the skin is determined, as in pickling, by drying.
Bread alum
Recipe 1Stir 200 g oatmeal in 1 liter of hot water and add 10 g malt. Insist this mixture for 6 hours at a temperature of 60 ° C, then lower the temperature to 40 ° C and add 20-30 g of kefir or yogurt.
Maintaining the temperature at 40 ° C, insist the composition for another 12-20 hours. Then dilute the resulting mixture with 1.5 liters of water, add table salt at the rate of 50-60 g per 1 liter and put the skins in the solution.
Recipe 2
Stir 750 g of oat flour in 1 liter of hot water, add 20-30 g of kefir or yogurt and leave for 12 hours at 37-40 ° C. Dilute the mixture with 5.9 liters of water, add salt at the rate of 50-60 g per 1 liter, put the skins in the solution and keep them at a temperature of 37-40 ° C.
After pickling, the skins are washed with running water, and then, like after pickling, they flesh again, after drying them and removing excess moisture with a rag.
TANNING
In the process of pickling, under the influence of acid in the skin tissue, collagen fibers are destroyed, which makes the skin soft and easy to tear, and tanning restores its strength. Tannins bind collagen fibers to each other, envelop them and prevent fibers from sticking, even when exposed to water.
At home, 2 main methods are used: tannin tanning and alum tanning.
Tanning is called tanning with vegetable decoctions. So, to prepare a tanning broth, 500 g of willow or oak bark is poured into 1 liter of water, boiled for 10-15 minutes and 50 g of salt is added. After a day, filter the infused broth. The efficiency of tanning will increase if you add a decoction of horse sorrel roots (prepared in the same way) to the decoction of the bark in a ratio of 10 liters to 2-2.5 liters.
The skin is impregnated with a tanning composition. For this, the skins are either soaked in a container with a tanning agent, or they are applied to the inner surface of the skin with a brush (smear).
Periodically, a thin strip is cut from the skin and the cut is examined through a magnifying glass. As soon as the yellow-brown tanning agent saturates the leather completely, throughout the entire thickness, tanning is stopped. The skins are spread on a flat surface for 1-2 days to dry.
Among the many recipes for alum tanning, the most popular and reliable is the use of chrome alum. For their preparation, 7 g of chrome alum and 50-60 g of salt are taken per 1 liter of water. If you want your skins to become even softer, you can add 10-12 g of potassium alum to the described composition.
The skins are dipped in alum tanning agent for a day. The degree of readiness of raw materials is determined in the same way as in tannin tanning - by cut. At the end of tanning after 1-2 days of drying, neutralization is carried out.
RINSING
Washing is required only for skins that have been soaked in tanning agent. When processing skins with butter, this step is skipped.
The wool is washed with running water. You can add shampoo to the water to make the fur silky. However, be careful to
the detergent has not come into contact with the skin. Washing is categorically contraindicated for tanned leather!
FAT
The fattening is carried out in order to make the skin supple and soft. For this, the skin is pulled on a rule and the skin is coated with a fat emulsion using a brush or tampon. The emulsion should be warm (about 40 ° C).
Fat emulsion
Recipe 1Mix equal parts egg yolks and glycerin, beat the mixture with a mixer.
Recipe 2
Grate 100 g of laundry soap and dissolve it in 1 liter of boiling water. Then, stirring continuously, add 1 kg of pork fat there. Turn off the heat and pour in 10 ml of ammonia.
When applying the emulsion to the flesh, try not to stain the fur. If fur contamination still cannot be avoided, remove the emulsion from the hairline with a cotton swab dipped in gasoline.
After fattening, the skins are dried again in the open air. Depending on their thickness, drying can take from several hours to 1 day.
DRYING
After drying the skin after fattening, it is slightly stretched, and the skin is treated with a pumice stone or a scraper. This procedure is carried out after, when stretching, white spots begin to appear on the skin, similar to drying.
Skinning can be done both at home (if the characteristic smell does not bother anyone), or put this process on a conveyor belt by renting a workshop and hiring workers. Such an activity does not require special skills, it is easy to learn it. However, when starting a business, you should be aware of the list of animals whose skins can only be processed by enterprises that have the right to do so, in accordance with current legislation.
Uncertified dressing of squirrel, beaver, otter, ermine, Siberian weasel, marten, fox, mink, muskrat, arctic fox, wolverine, lynx and sable skins is prohibited.
It is worth starting with the processing of rabbit fur - it is the most affordable, the least demanding on the skill of processing and, of course, has the lowest purchase price. Rabbit products are always in demand on the market. And if the startup brings profit and pleasure, in the future you can establish a farm for raising these animals, having received a closed production cycle. In addition to rabbits, you can also do sheep and goat hides. According to businessmen, one skin brings in income from $ 20 to $ 50, depending on the type of fur / wool.
The processing of hides, which we will describe below, consists of three main stages: preparatory operations, actual dressing and finishing.
Preparing the skin for dressing
The preparatory stage consists of soaking, skinning, washing and degreasing the skin and fur. For soaking, you need to prepare a saline solution at the rate of 30-40 grams of table salt per liter of water at room temperature. Be sure to add an antiseptic that inhibits the growth of microorganisms and prevents possible rotting of the skin, such as crystalline carbolic acid (phenol) or zinc chloride. The latter also helps to anchor the hair in the skin and is especially useful when working with already damaged hides. Dip the skins into the prepared solution using a press. Soaking can last from several hours to three to four days, depending on the thickness of the skin and the duration of storage of canned skins.
It is important to mix the skins frequently, every two to three hours, so that they are evenly soaked. After 12 hours, you can change the solution. This will speed up the process.
The skin is ready to move on to the next stage if:
- the skin has become uniform, soft and easy to stretch;
- the hair is held firmly, does not fall out.
Then the skins are wrung out and hung up to drain off the remaining water. Do not overtighten them during push-ups, otherwise streaks may remain.
The next preparatory step - fur coat - applies only to dry skins. Examine the item carefully for the presence of subcutaneous muscle and fat residues. They must be cleaned off, and the entire surface of the flesh should be slightly scraped with a knife in the direction of the hair roots.
Washing and degreasing is the last preparatory step. The remaining fat, which is not visible at first glance, will prevent further processing of the hides. In order to get rid of it, you should prepare a degreasing solution. Its composition is simple: seven to eight grams of washing (soda ash) soda per liter of water (or a third of a glass of soda per bucket of water). The solution is prepared warm, the temperature of the human body. The skins in the solution should float freely. When the ox acquires a yellowish tint, you should change it. After two to three hours, the skin of the skins (inner part) should turn white and its fat content will cease to be felt. Check - the skin should "creak" under the fingers. The skins are dried, the wool is shaken off the water, and the skin is wiped with a dry cloth.
If you overexpose the skins in a degreasing solution, they can lose their elasticity and strength, and fibers will become visible.
Skinning: a description of the main techniques
Dressing of skins, which can be produced by two main technologies: pickling and pickling (pickling). Both methods of dressing skins are used at home, while only pickling is used on an industrial scale.
Picking involves the processing of skins using pickels - medium-strength water solutions of sodium chloride with acids: inorganic (sulfuric, hydrochloric) or organic (formic, acetic, wine-acetic, milk). Sulfuric and hydrochloric acids have a much more active effect on the material. The skins processed by them do not retain their good qualities for long. Over time, their strength is lost. When exposed to inorganic acids, the color and structure of the skin can also change, the natural shine and beauty of the fur disappear. In order to prevent the loss of the presentation of the hide after the pickling process, you need to neutralize the acid.
Organic acids tend to have a softer and sparing effect on hides. The most accessible and common acid among them is acetic acid. The skin processed with it is elastic and lasts a long time.
Ingredients for the vinegar pickel: 15-35 milliliters of concentrated acetic acid and 40-50 grams of sodium chloride per liter of water. If it is impossible to get concentrated acid, then 20-50 milliliters of food acid (acetic essence) 70% concentration are taken for one liter of water.
Pickel can be made from sour house wine. It is diluted with water in proportions of one to three, then table salt is added (40-50 grams per liter). Only white wines are suitable, since reds tint the skin, and most importantly, the wool.
The entire skin processing process is carried out in an enamel, plastic or wooden dish that does not undergo oxidation. The pickle into which the washed and defatted skins are immersed should be at room temperature. For one kilogram of skins, you need to take three liters of solution (preferably four to seven liters) so that the skins float freely in the solution.
The procedure takes from five hours to four days, depending on the thickness and density of the skin tissue. For hare skins, for gophers and other animals with thin, loose skin, five to ten hours are enough. The skins of ferrets, raccoon dogs, jackals, fur-bearing animals with medium-thickness skin, as well as roe deer and young deer take a longer time - from 12 to 30 hours. For thick skins of a wolf, bear, elk, wild boar, the time spent in a pickel is up to four days. It is important to constantly stir the skins so that the pickle soaks them evenly.
To understand whether the skin is ready, you need to fold a small corner in four, pressing firmly with your fingers, and then straighten it. If there are characteristic white seams, it's time to get the goods. Slightly wringing out the skin, let it sit for 10-12 hours at room temperature. After that, the skin can be considered finished.
The second method of skinning is fermentation -involves the use of fermented bread-type sourdough. The latter can be prepared from oatmeal, barley, wheat, rye flour and bran. This method is more gentle and suitable for home use. Fermentation is essentially the souring of the skins. There are two processing methods: perch and spread.
When dipping fermentation, knead the batter at the rate of 150-200 grams of flour per liter of hot water. Table salt is added - a full tablespoon per liter of dough. In order to speed up the fermentation process, add some yeast. Dip the skins into a solution of room temperature so that they float freely. Then the dishes should be closed with a lid and left to "ferment" the skins, stirring them constantly (every two to three hours).
After a day of fermentation, the skins should be checked for readiness. The readiness of the skin is judged by the same signs as when pickling. There is another way to check: you need to remove the edge of the skin from the kvass and try to separate a thin layer of skin from the side of the hair with your fingernail. If the peeling of the epidermal film from the main layer of the skin is noticeable, then the skin is ready. It needs to be squeezed out and hung to dry.
The lack of perch coloration manifests itself in the complexity of the subsequent cleaning of the skins from the dough. To avoid it, use the method of spreading fermentation.
In the process of kneading, a large amount of flour and sour cream are added to the dough with salt and yeast. The dough is left in a warm place until fermentation begins. Then the resulting mixture is smeared on the flesh (the lower layer of the skin, subcutaneous tissue) with a layer of 0.5-1 cm. The skins are folded to the flesh, covered and left to ferment. In order for the layers of the mixture to evenly cover the skin, use a wooden spatula.
To achieve the best result, the dough can be changed once a day, removing the old one and applying the new one with the same spatula. The readiness of the skin, as in previous cases, is indicated by the characteristic "drying" and flaking of the epidermis.
Remember: the softer the water used to prepare the solutions, the better the dressing is. When using hard water, it is recommended to soften it by adding technical ammonia in the amount of one tablespoon per 10 liters of water.
The last stage is finishing leather and fur
Skin finishing is used to remove stuck together fibers that form during the drying process. In the process of finishing, the skins are crumpled and stretched by hands, the flesh is loosened on the bracket, braid, with a center slingshot. For this, all kinds of tables and stretching systems are used. The finishing of the hairline consists of brushing and brushing it to make the fur lush and shiny.
And remember, if a hole accidentally forms on the product, it must be sewn up during the drying process, until the skin is completely dry. The seam should lie parallel to the ridge line. The round hole is slightly lengthened and spindle-shaped, this darning method will not create creases.
If you decide to start dressing skins on a production scale, you cannot do without the following machines:
- Chipping machine designed for preliminary cutting of hairline.
- Recoiling drums for rolling and shaking skins.
- Skin softening device.
- Carding machine.
- Shearing machine for trimming the hair of skins.
- Centrifuge for pressing the skins.
To acquire the required skills, you can use
