Trying to tan a hide

[Keith]

So followed the instructions as best as I could, apart from the end I hung it apose to nailing into a fence.
It looks like a wrinkled avatar. Have I ruined it??
Can't seem to attach a photo.

Thanks.

You must peg them out so they are taut when they are wet, then let them dry and then apply the softening agent in the kit. If dry now, try and put it back in the solution to soften, then peg it out properly all the way round with galvanised nails, then softening agent and breaking followed by sanding the bloom off.

I've use all the first solution, and pored it out. Think I could soak it in warm water then peg up?

[Keith]

Yep drum tight when wet. Let dry, use lube, let dry, sand, break on beam if too crispy.

I find a pallet is easier, doing it horizontally rather than try ing to hold a soggy hide up with one hand and nail with the other on a fence. (Nailgun?)

So will sanding get the blue off the skin? Break on beam meaning the bin??

[Camel]

So followed the instructions as best as I could, apart from the end I hung it apose to nailing into a fence.
It looks like a wrinkled avatar. Have I ruined it??
Can't seem to attach a photo.

Thanks.

You must peg them out so they are taut when they are wet, then let them dry and then apply the softening agent in the kit. If dry now, try and put it back in the solution to soften, then peg it out properly all the way round with galvanised nails, then softening agent and breaking followed by sanding the bloom off.

I've use all the first solution, and pored it out. Think I could soak it in warm water then peg up?

I would be more inclined to soak it back in a salty solution, probably the same amount of salt as when making up the tanning solution. Once it is back to soft, I would rinse it and then peg out on a flat board, 3/4 ply is great stuff for this, use galvanised nails, you only need thin ones, so you don't get rust spots around the edge of the skin, then let dry and follow instructions to, the letter, on how to use softening agent, let dry, and if you don't have a tanners beam, which is a round wooden post around 15 inches thick cut in half or you could use it round, I would then lay out a piece of short pile carpet and break it on there using a breaking tool. Sanding will get rid of the flaky bits on the tanned side of the skin and make it nice and smooth. The blue colour gets less as it dries, but it will always have a blue tinge to it.

1 quick tip, don't tip your salty water on the lawn, and don't spread the wet skin on the lawn, it will kill the grass. Google Tanners Beam, there will be photos somewhere there, same with breaking tool.

[Gadge]

A better search term is 'fleshing beam dimensions' - brings up plenty of dimensioned images.

The blue colour is due to the chemistry of the tanning agent used [chromium], and it will always look a bit bluish.

There are other tanning agents, such as wattle bark or even teabags, which won't result in the blue tinge, but the chrome tan process is by far the easiest one to start out with.

Get the other parts of the tanning process sorted, before you start playing with those.

[Gadge]

Here's a tanning doco that used to be up on the web, for free download so long as its attribution was included.
Keith D, kindly let me know if this presents any copyright problems.

An Easy Guide to Making Leather At Home

Gil Hardwick

Handbook - ISBN 0 646 30074 1 - © Gil Hardwick 1996.

DISCLAIMER: No responsibility whatsoever is accepted by the author for adverse effects arising from misuse of any processes, chemicals or other materials described herein; including poisoning of humans or animals, detrimental environmental impacts, or prosecution by local authorities for pursuing a noxious industry without permission.

CONTENTS

Introduction
The Nature of Animal Skins
Basic Steps in Making Leather
Chemicals Used in Home Tanning
Some Useful Tanning Solutions
Glossary of Terms
References

INTRODUCTION

There are literally 1,000s of tanning methods and recipes dating right back through the ages, although it is difficult in Australia for the small-scale home tanner to obtain basic, useful information suited to local conditions. That is the reason for putting this little book together.

It is presented as a guide to begin mastering the process of making leather, so please feel quite free to experiment. Before doing so, however, do seek to understand the nature of the materials; read up on organic chemistry, and endeavour to come to terms with the sheer magic of the colloidal gels which comprise the naturally protective covering of animals.

There is no discussion here of hunting, killing or skinning animals, and those interested are referred to John Leidreiter's outstanding A Handbook on Knives Skinning & Tanning. Here it is anticipated that readers will also be primarily Permaculturists and others interested in making good use of the abundance of skins already available on farms, local abattoirs and pet-food works, rather than seeing them too often going to waste, or used as "mulch" on someone's vegie patch.

Nor is there any discussion of chrome tanning methods for heavy hides. The use of aluminium salts is included only to maintain perspective on the processes taking place during tanning. Tanning agents themselves are astringent; that is, they precipitate solids from solution. It must be remembered that these materials will also kill soils, so keep them away from the garden or flower bed, and do not flush them into sewerage or septic systems.

Do not save solutions for re-use, as they become contaminated with fungal mould and bacteria. Make up only enough for the job at hand, and then dispose of it properly.

Depleted solutions generally contain only small amounts remaining of the chemicals mixed in to start with, and the quantities typically used by the home tanner can be safely disposed of by dispersing it over a wide area of grass and then watering it in, or over a gravel driveway for example. Large quantities must be disposed of according to EPA requirements. See the local Shire for details.


THE NATURE OF ANIMAL SKINS

Green animal skins have three main layers:

1. Epidermis: the thin surface layer of dead skin, which normally flakes off as dandruff during the life of the animal, and is steadily replaced from the living "grain" layer immediately below.

2. Dermis: the corium or true skin. The dermis itself comprises two sub-layers which in some animals can be seen quite clearly (e.g., sheep skins), and in others not so clearly (e.g., kangaroo skin). These two layers are:

a. The Grain Layer, in which the hair shafts are embedded, and which has a patterned surface unique to each animal.

b. The Fibre Layer, which forms the main bulk of the dermis and comprises a mass of minute interlacing bundles of fibres. These fibre bundles give leather its tremendous strength and flexibility, while still allowing it to "breathe".

3. Flesh Membrane: adipose tissue which joins the true skin to the carcase of the animal.

The epidermis and flesh membrane are removed in the early stages of processing, during the various stages of "wet work", so as to leave the dermis or true skin itself to be finally tanned into leather.

Animal skins, like other parts of animals, are colloidal. A colloid is defined as any physical system comprising two phases; the continuous (usually liquid) phase, and the dispersed (usually fine solid particles light enough to defy gravity and so remain in suspension) phase. The three main organic colloids derived from animals are: Albumin, from egg whites, muscle tissue viscera, etc., which coagulates on heating; Gelatin, from sinews, skins, etc., which absorbs massive amounts of water, and melts on heating; Keratin, from horns, claws, finger nails, hair, etc.

In the case of animal skins, the colloidal system consists of an extremely fine matrix of collagen (a high quality complex gelatin) fibres dispersed in a fluid phase of simpler gelatins, lymph, elastin, mucin and reticulin. When the actual process of tanning takes place, the collagen fibres are precipitated by the tanning agent, and the remaining fluids are dissolved and washed but. If glue or gelatin are being made, on the other hand, the collagen itself is broken down into gelatin, and the whole becomes a single mass of jelly.

Technically, tanning proper using tannin or chromium salts also irreversibly changes the chemical nature of the collagen fibres into solid protein fibres.

A less stable form of tanning carried out with aluminium salts is actually called tawing. This process rather coats the collagen fibres with a layer of alumina molecules, and because they are sticky are likely to stick together again as the leather dries. The alumina molecules are also water soluble, so if the leather is washed again they are likely to be washed out, and the leather will need to be tanned again if it is to be of any use.

For these reasons, tawed leather is dressed with a fat-liquor while it is still damp, after it has been through any further dying processes, and then the fibres broken further by working the leather over a stake as it dries. It is then aged for a few weeks in order to fix the alumina molecules to the collagen fibres more permanently, and subsequently the garment is dry cleaned.

The third type of leather is buckskin, made traditionally by the Indians of North America, by partial putrification of the skin in water in order to break down the gelatin phase, and then coating the fibres with a fat-liquor paste made from deer brains before breaking it by working over a stake and then chewing so as to mechanically separate the collagen fibres.



BASIC STEPS IN MAKING LEATHER

A. Preparation

1. Salting and Storage

Green skins can be kept for some time after skinning, although this depends on the season. In summer skins will keep for up to a month, and up to 4-5 months during winter. Take care to process skins held over winter before it gets too warm in spring, and insects and their larvae looking for a free meal become too numerous.

There are numbers of methods for salting skins, some quite complex, but a simple and effective treatment is to spread the skins out flat on a sloping surface in a shady place, flesh-side up, and give them a good covering of salt; for light skins a good 5 mm thickness. Fine ground table salt which already contains a tiny percentage of alum to make it flow freely is best, although the coarse butcher's salt is both satisfactory and far cheaper. It is important to work the salt into every crease and fold, and around the edges.

The skins are then left for a day, until the brown liquor drawn out by the salt has drained off. Then another layer of salt is added before folding each skin up; bellies into the middle first, then tail end and neck into the middle, then the whole folded in half again into a pillow. Folded skins can be tied up into bales, or simply stacked until ready for processing.

B. Wet Work

2. Sorting and Cleaning

First, sort the salted skins into various grades depending on their weight and condition, and decide what types of leather are to be made. Remove dirt and salt by soaking in clean water until they are in a soft, flexible condition similar to when the skin was taken off the animal, usually overnight.

Between each operation until tanned and ready for finishing, rinse them again in clean water enough times so that the final rinse remains clear.

3. Fleshing

Commercially the flesh membrane and adhering fat, muscle tissue, etc., are removed by machine. For home tanning a simple fleshing tool, rasp, or blunt knife will do the same job, although if using any sort of knife great care must be taken not to slip, and so score or cut the skin.

In practice, fleshing by hand need not be overly thorough, so long as too much fat and crud are not left adhering to the skin surface. It is far more important to scratch through the membrane to allow the tanning solution to penetrate through to the dermis proper. Any remaining shreds of membrane will also tan, and can be scraped or sanded off more easily later.

4. De-hairing

a. Fellmongering is the traditional method, although used more generally today for sheep skins so as not to waste the wool, which can be plucked and sold separately as a whole fleece in fairly good condition.

The technique is to not salt the skins to start with, but allow them to begin slight putrification. Cut the feet off so there is no bone in the pile, then pick each skin up in the middle of the back with the leg ends dangling down, and drop it onto a bag or an old tarpaulin so that it forms a neat round pile. The pile of skins are then covered with bags and allowed to "sweat" for a period, varying from 1-2 days in summer to 3-4 days in winter. If left too long the skins will turn to a putrid mass of jelly.

A close eye must be kept on the skins at this stage so they do not spoil. As soon as it easily comes away from the pelt, pluck the wool and bale it up for sale. The material should not smell too much, since the bacterial process is aerobic. The astute nose and eye can tell the condition of the pelt by this time. When they are done, proceed with soaking and fleshing as normal.

b. Liming. Soak the skins in a solution of hydrated lime for a day or two, until the hair slips off easily. The lime is highly caustic, so wear gloves. This process plumps the skin structure and opens the fibres up while it is wet, and softens the surface so the grain and hair can be rubbed off. Take care that on exposure to air, the lime does not dry out on the skin. In that situation it will be converted chemically to calcium carbonate, and leave a hard white patch on the leather which is impossible to remove.

Check the skin regularly, and usually after about two days the hair and grain will begun to slip off quite easily. Throw the skin over the fleshing beam, and rub all the hair off with a flat stick or blunt knife.

5. Washing and Drenching

From this point the now bare skin is called a "pelt", and the next steps depend on what type of leather is to be made. Some skins are inherently very greasy. Sheepskins, for example, contain a great deal of lanolin which must be taken out if it is planned to make mats or rugs. Kangaroos when feeding well during winter will deposit a lot of yellow fat in the adipose membrane, which cannot all be taken off when fleshing, and of course pigs are notorious for their subcutaneous fat.

Once fleshed, the worse cases can be dry-cleaned using white spirit or petrol, and then washed in a strong laundry detergent. Be sure to work outside in the open air while stripping grease with these solvents, or in a well ventilated area. Generally speaking, wash and rinse the pelts thoroughly in a washing machine (or by hand) using a good dishwashing liquid or similar product like "wool wash", avoiding if possible at this stage the far more caustic laundry detergents.

If left in a highly alkaline state the final leather will be stiff and hard. At a minimum, drench the pelts in an acid pickle for 1-2 hours to bring the pH down before tanning. This type of leather is better used for shoe uppers, briefcases, and so on. Depending on the type of skin, further drenching for as long as 36 hours or more in cold weather can be used as part of the tanning process for fine kid, glove and garment styles of leather, although it must be kept in mind that these will be much emptier leathers, and may need to be stuffed while tawing using a paste rather than a solution.

Be sure to rinse the pelts repeatedly in clean, clear water between each operation until tanning is complete, and the leather is ready for finishing.

6. Tanning

See the section on Useful Solutions for various recipes.

Unless otherwise stated, the tanning method is to suspend the drenched pelts evenly throughout the liquid, trying to avoid folds and wrinkles. Plunge them about from time to time until tanning is complete, in order to obtain an equal effect of the tanning solution over their whole surface. For large pelts use a deep drum and hang them over sticks tied at each end with string to the drum handles. Plunge them and paddle the solution regularly to ensure that affected parts receive good exposure to the pickle. In the case of sheepskins with the wool left on, the wool itself will soak up a large amount of solution, and so much larger quantities are required for tanning to be effective.

A simple test for whether tanning is complete, is to cut a sliver from the thick end (butt end) and see that the colour is even through the thickness of the pelt. Otherwise, place the sliver in a little boiling water; if it is not properly struck through the piece will shrivel and curl up, and go rubbery.

C. Finishing

7. Dyeing and Fat-liquoring

When the tanning process is complete, sufficient for the pelt to withstand the temperature of boiling water without shrinking, it can be dyed the desired colour. When this is done, the tanned pelts are partly dried (sammed) and an oily fat emulsion (fat liquor) applied. This soaks into the pelt and causes the individual fibres to be coated with oil molecules, to prevent them from gluing together as it dries so the pelt will remain soft and flexible.

8. Drying and Staking

This is an important part of finishing the leather, as it must not be dried too quickly. Keep it out of the sun and wind in particular. Stretch the wet leather out on a frame, keeping a nice symmetrical shape. When it is almost dry, work the leather thoroughly back and forth over a stake with an action similar to polishing shoes with a cloth, so that the pelt fibres are kept loose and separated.

In winter when it is cooler and more humid, the leather will dry slowly and time can be taken over this process. In summer when it is dry and hot, however, it has to be done quickly; always work out of the wind, indoors or in the shade. If when the leather dries it is still too stiff, damp it back with a wet cloth and keep working it over the stake until it is finished.

CHEMICALS USED IN HOME TANNING

WARNING: Always wear overalls & gloves while handling tanning chemicals.

1. Materials

Acetic acid, or vinegar

* Aluminium salts: Alum (aluminium sulphate)
* Ammonia alum (aluminium ammonia sulphate)
* Potassium alum (aluminium potassium sulphate)

Carbolic acid

Caustic potash, or potash (potassium hydroxide)

Caustic soda, or lye (potassium hydroxide)

Chromium aluminium salts:
* Chromium sulphate
* Chromium potassium sulphate

Salt (sodium chloride)

Slaked lime (calcium hydroxide)

Sulphuric acid

Tannin (tannic acid)

Washing soda (sodium carbonate)

2. Sources

Some of these chemicals are either difficult or expensive to obtain in Australia. To obtain the cheapest rates they must be purchased in bulk lots of one tonne or more, otherwise small package amounts from a pharmacist at considerable cost.

Most of the basics, however, can be got with a little ingenuity. Bricklayer's lime can be used for de-hairing. Ordinary farm alum is available from most rural supply outlets. Sulphuric acid can be purchased from Auto Parts retailers. Common household salt can be bought anywhere.

Also, browse through any of the old farming and bush-craft books for ideas and methods used by the pioneers. Instead of becoming frustrated, adapt your techniques to what skins come your way, and what materials you are able to obtain locally.

3. Procuring Tannins

While it appears sound to avoid using "manufactured chemicals" in favour of "natural" tannins from vegetable sources, for the small-scale home tanner several facts must be brought to mind before proceeding.

Firstly, large quantities of tannin are required to tan leather. Even from the best trees producing as high as 17% bark tannin, very large quantities indeed of such bark must be collected in order to extract sufficient active principle to do the job. Large acreages must be planted to ensure a reliable supply, and anyone who has spent the many hours stripping and chopping bark by hand, or alternatively has used a mulching machine to chip foliage for the same purpose, knows how much work is required.

Secondly, bark tanning is an extremely slow process. While it can produce the very best quality leather, the investment in time and sheer hard work must nevertheless be balanced against the return.

Much easier and quicker processes using tea or other sources still produce a very satisfactory result, such that only very experienced tanners would pick much of a difference.

Finally, tannin from whatever source remains an astringent chemical. Just because it is of vegetable origin does not mean that it is not potentially harmful. It will kill soils just as surely as alum will, and if ingested in too high doses by drinking too much tea for example, it will cause an often fatal cirrhosis of the liver. The message is, whatever chemical, use it wisely.

Having said all that, tannin production nevertheless remains an economically viable proposition as a product of any good Permaculture or agroforestry operation. Some of the richest sources of tannin in Australia are, for example:

Botanical Name Common Name Useful Parts
Acacia spp. Wattles Bark
Castanea spp. Chestnuts Entire tree
Eucalyptus spp. Bloodwoods & Red Gums Kino (oozing red sap)
Punica granatum Pomegranate Bark, Fruit rind
Quercus spp. Oaks Bark, Acorns

SOME USEFUL TANNING SOLUTIONS

Acid Pickle

40 litres water
450 ml sulphuric acid
5 Kg salt

Dissolve salt in water first in plastic tub, then very slowly add acid. Used for drenching pelts after liming and de-hairing is complete. This pickle is also useful for dressing small fur pelts, such as rabbit, which can later be "fleshed" by scrapping or sanding after tanning is complete.

Alum-Carbolic Acid Soak (a)

40 litres water
2.5 Kg salt
1.25 Kg alum
150 grams carbolic acid crystals

Carbolic Acid Solution (b)

40 litres water
15 tablespoons carbolic acid crystals

Relax the pelts in the carbolic acid solution first, then soak them in the alum solution for six days or so before removing and draining. When drained, apply a coat of sulphonated neatsfoot oil and allow to dry.

Relax the pelts again in a further carbolic acid solution before working over a beam until pliable. Pelts will be soft and white in colour when properly done.

Alum Paste

125 grams salt
375 grams potash or ammonia alum
Fresh yolk of 4 hen eggs
100 g olive oil
1 Kg flour

This process was known traditionally as tawing, and drumming pelts in the paste after bating and drenching yielded a fine kid leather. After being finished, the leather requires a further few weeks of aging in order to fix the tan permanently. In a tanning factory these quantities were sufficient for about ten medium lamb pelts.

For ordinary home tanning, dissolve salt & alum in a little water, then add flour and enough water to make into a smooth, thick paste. Spread the pelt out flat and apply the paste to the flesh side and leave a day, then scrape off and repeat over 2-3 days until done. For a fuller, softer leather, add the fresh egg yolk and olive oil to the paste.

The process can be speeded up by keeping the paste quite warm; maintaining the temperature to 30oC (86oF) for twelve hours should be enough.

Bark Tannin Solution

Shredded wattle bark
Enough soft or rainwater to cover

Finely shred the bark of any of the wattles (also oak, chestnut & others.), sufficient to fill a 25 litre tub. The bark needs to be shredded as fine as possible; putting it through a mulcher is quicker, although chopping it on a block with an axe does the job well enough. Boil the water and pour over the bark until completely covered, then stir occasionally while infusing for 2-3 weeks, and while the rest of the wet work is being done.

When the pelts are ready for tanning, strain enough of the tannin infusion through hessian into a clean tub, until it is about 3/4 full. To this quantity add 350 ml vinegar, or less depending on how long the pelts had already been drenched. For light pelts this strength should be sufficient to allow tanning to be completed within about two-three weeks.

Bate

Chicken or pigeon manure
Water

Half fill a drum with the chicken or pigeon manure, then fill with water and leave 1-2 days to ferment. Strain the liquid off through hessian into a tub, and soak the de-haired pelts in it until they just begin putrification.

Be careful that this is an alkaline ferment, and while there is an initial early rise in pH due to lime entering the solution, pH can also rise again suddenly as the ferment ages with the resulting leather being hard and stiff.

Check regularly, and when satisfied drench the pelts before scouring and tanning.

Dehairing Solution

4.5 Kg fresh hydrated (slaked) lime
200 litres water

Mix lime well in 20 litres water in a barrel, then add the rest of the water and stir again, using a paddle. Move the pelts about and paddle several times a day for 1-2 days until hair slips easily. Remove pelts and scrape off the entire fur and grain over a beam.

Experiment with dehairing recipes using lye or sodium sulphide to get a quick slip solution. When in the bush try using a slurry made from wood ash from your camp fire.

Fat Liquor

1 part water
1 part sulphonated neatsfoot oil

Should be warm when prepared and used. While breaking and slicking the tanned pelts, work in a warm place. Try also using fresh brains mashed into a fine paste in a blender, or make a liquor using oil emulsified by boiling with either soft soap or grated laundry soap dissolved in water.

Puering Solution

A disgusting process. Half fill a drum with dog manure, then fill with water and leave 1-2 days to ferment. Proceed as for bating. Puering is an acid ferment, compared with the alkaline bate, and while obnoxious nevertheless yields a much softer light leather than bating.

Red Gum (Kino) Solution
(A Nyungar traditional method from the south-west WA.)

Collect a good bucket full of the red gum which oozes from Marri or other of the bloodwoods (not blackboy resin, which is used as a shellac). Boil the gum in a bucket of water and let simmer until it is all dissolved. Let it cool first, and then place pelt in the solution. Takes about three weeks to tan right through.

Tea Solution

4 pkts cheap tea bags (200s)
250 g salt
25 l water

Put all the tea bags in a 25 litre tub. Boil the water and pour it over the tea bags in the tub. Place a screen with a weight on top to keep all the tea bags submerged, then let it stand for a few days until the wet work is done.

Once the skin has been fleshed and de-haired, strain the tea bags from the tannin bath, squeezing them gently dry so as not to lose much solution.

Add the salt and stir until dissolved. If the pelt has had a good drench in the acid bath, that should be enough. Otherwise, add to the solution 350 ml vinegar or alternatively a teaspoon of sulphuric acid.

Sufficient for one medium kangaroo or goat skin, but it takes a good two weeks at a minimum to strike through.

Finish by soaking overnight and rinsing until a lot of the dark tea colour is washed out, then slick and bowl it on a flat surface while still wet to make the fat-liquor penetrate right through. Lay it out in the cool shade to dry slowly, and then stake thoroughly just before the leather begins to finally dry right out.

Salt-Alum Solution (1)

24 litres water
2 Kg potassium or ammonia alum
500 g washing soda
1 Kg salt

Dissolve alum in 16 litres of water in a tub, dissolve soda and salt in a bucket of water, then pour the soda-salt solution very slowly into the tub while stirring vigorously. Be careful with mixing, if the final solution goes milky it will not tan.

This solution is more strictly analogous in theory to a chrome tan, and is quite capable of producing a very satisfactory result. It can be difficult to obtain the right chemicals, however, and it is much more common to use salt with the alum than soda. The use of the salt is to suppress swelling of the pelt, and allow it to take up the alumina from the solution more readily.

Salt-Alum Solution (2)

25 litres water
2.5 Kg salt
1 Kg alum

Dissolve salt & alum in warm water, then allow to cool before using. Usually takes up to a week for light pelts, or less time in hot weather. Yields a slightly harder, emptier white leather which will need to be stuffed during finishing.

Add olive oil and/or egg yolk to the fat-liquor, and bowl and slick the leather in plenty of liquor on a flat table surface while still reasonably damp before staking, then stake and stretch thoroughly.


Bating: Removing lime by fermentation and bacterial action in chicken manure bath.

Beaming: Working tanned skins over a tapered, rounded beam to soften.

Bowling: Rolling tanned skins on a table to soften and work oil into them.

Breaking or Stretching: Separating the fibres of partly dried skins by working over a stake.

Butt: The thick end of anything; usually the thickest part of the skin from around the neck, back & shoulders. On kangaroos and other marsupials, however, the flanks and loins form the butt end.

Curing: Preserving skins by salting and/or drying.

Currying: Introducing grease into leather and finishing.

Damping Back: Wet a tanned skin again which has become dry before being properly softened.

Degreasing: Removing grease by scraping or slicking, or using solvents.

Dehairing: Softening and parting the grain (epidermis) and hair or wool from the main part of the skin (dermis), usually by liming, but also by sweating (fellmongering), or using lye or potash.

Deliming: Removing alkali to prevent it from interfering with the tanning process, either by neutralising with acid or fermenting with bacteria (bating).

Depilation: Any process involving the removal of hair, wool or fur, including dehairing and plucking.

Depleting: Any action which tends to loosen the hair, fur or wool.

Dermis: The true skin of any animal; that part from which leather is made.

Drenching: Neutralising limed hides in a mild acid bath, usually of lactic acid, dilute sulphuric acid, or vinegar (acetic acid).

Dressing: Oiling freshly finished leather as well as old used leather to preserve it and keep it soft.

Drumming: Operation of a rotating drum in which hides & skins are tumbled to assist in cleaning, tanning, fat-liquoring and stuffing.

Dubbin: A mixture of oil & tallow for stuffing leather.

Epidermis: The external layer of skin (grain) containing the hair follicles, including the layer of dead flaky skin continuously sloughing off the living animal.

Fat-liquor: An emulsion of soap and oil, a mild alkali such as borax and oil, or a sulphonated oil, in which skins are worked after tanning and washing.

Fellmongering: Allowing skins, especially sheep skins, to sweat and begin putrefying so as to loosen the grain and wool, allowing it to be plucked.

Finishing: Currying, or softening the tanned skin by working, rolling, etc, while forcing oils & greases into the pores. Also dying and colouring at this stage.

Fleshing: Scraping the flesh side of the skin to remove the membrane and any flesh and fat, so as to expose the dermis to the tanning process.

Graining: Dehairing (see above).

Greenskin or hide: Untanned skin freshly taken off an animal.

Liming: Soaking in lime solution to soften the hair and grain.

Nape: The lower back part of the neck.

Neatsfoot Oil: A pale yellow fixed oil made by boiling the feet and shin bones of cattle, used in leather dressing.

Paddling or Handling: Stirring skins about in the tanning solution.

Pickling, or Tanning: Soaking in any of the various tanning solutions.

Plunging: Working skins up and down in the tanning solution so as to expose all parts of the skin to fresh solution.

Rawhide: Untanned and dehaired skin or hide prepared by stretching and dry curing.

Samming: Partly drying skins.

Scores: Inadvertent cuts, notches or furrows made with skinning and fleshing tools causing flaws in hides and skins. Scores very badly devalue the finished rawhide or leather.

Scouring: Washing skins to clean them.

Sides: Half hides, usually cut down the centre of the back for easier handling.

Skiving: Thinning skins by paring them back evenly with a knife.

Slicking, or Scudding: Working liquids out of skins by scraping.

Soaking: Softening and cleaning the skins of dirt, blood, salt, etc.

Staking: Working the skin over a stake or stake knife to break or soften it.

Stuffing: The working in of dubbin or oil.

Struck Through: When the tanning agent has penetrated all the way through a hide or skin.

Sulphonated Oil: An oil treated with sulphonic acid so that it contains sulphonic acids and is therefore partly soluble in water.

Tan: Any material which prevent putrification of hides and skins, especially by precipitating and separating the skin fibres from the gel (colloid) into a coherent mat.

Tannic Acid (Tannin): The astringent principle in many vegetable materials capable of precipitating skin fibres.

Tanning: Altering the nature of the skin or hide by precipitating its fibres in solutions of salt, tannin, acid, and/or other chemicals.

Tawing: Treating skins with aluminium salts, as in "alum tanning".

Tousing: Stretching, twisting and working a tanned skin to soften and make it pliable.

Wet Work: Including all of the various processes of soaking, fleshing, dehairing, deliming, drenching, scouring and pickling or tanning, prior to finishing the leather.

REFERENCES

Bennet H.G. 1921, Animal Proteins, Industrial Chemistry Series, Bailliere, Tindall & Cox, London.
Farnham A.B. 1950, Home Tanning & Leather Making Guide, Harding Publishing Co, Columbus, Ohio.
Federated Tanners Association of Australia booklet, What is Leather?
Grantz G.J. 1969:1988, Home Book of Taxidermy and Tanning, Stackpole Books, Harrisburg, Pennsylvania
Leidreiter J. 1990, A Handbook on Knives Skinning & Tanning, Tweed Heads
The Countryman 1981, Farm Handbook, WA Newspapers Ltd, Perth


Citation for this article:
Gil Hardwick, An Easy Guide to Making Leather At Home,
http://gilhardwick.org/tanning_leather.htm, August 2001
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All rights reserved © Gil Hardwick 2001

[DSD]

How did this and or the subsequent skin turn out?

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[barryb]

Yes Keith , keep us informed please mate. Watching with interest.