COMMERCIAL EXOTIC LEATHER MANUFACTURE FEATURES AND REQUIREMENTS OF A STATEOFTHEART ALLIGATOR TANNERY

1
COMMERCIAL EXOTIC LEATHER MANUFACTURE FEATURES
AND REQUIREMENTS OF A STATE-OF-THE-ART ALLIGATOR
TANNERY

• David R. Small
• Consultant and Master Tanner

2

• INTRODUCTION
• I suppose you could say that this speaker is an
  historic relic of another era in the United
  States leather industry! About seven years ago, I
  retired from a life-long career in the leather
  industry (with a few minor interruptions) where I
  had applied my Rensselaer Polytechnic Institute
  Chemical Engineering education. In following my
  career I roamed through ten states and Canada
  before being recruited to help start an exotic
  skin tannery in Baton Rouge, Louisiana. My career
  covered all aspects of goatskin, cattle hide,
  cattle whole hide, cattle split, pigskin and
  exotic leather manufacturing for shoe, bag,
  clothing, boot, belt and upholstery applications.
• My career encompassed an entire era of the US
  tanning industry, and its customers, for that
  matter. I have known most of the leading leather
  scientists, technologists, suppliers and
  businessmen from that period. Unfortunately for
  them, but

3

• fortunately for me, I have outlived far too many
  of them.And, sadly, I have watched while this
  once large, proud, strong and quite profitable
  small business industry has imploded on itself
  behind me. Major players in the industry have
  disappeared even very recently. None of the
  entities I previously worked for, some relatively
  quite large and prominent, are around today--no
  trace of them can still be found. Somehow weve
  managed to export all but a small scattering of,
  mostly giant, companies, including the bluing
  plants associated with your Texas big packing
  plants, from this once important industry.
• The Exotic Leather Industry I Know
• From the viewpoint of an experienced engineer,
  I will now attempt to present you with my
  personal, somewhat idealized, response to the
  question posed to me of whether or not I believed
  it would be feasible to develop and operate an

4

• exotic tannery in Texas, possibly somewhere in
  this general vicinity.
• Lets just get something straight at the
  outset. If someone is considering the feasibility
  of starting new exotic tanning facilities here or
  anywhere else, from experience I can tell you
  this is a big undertaking. The days of the small,
  family run bucket-shop reptile tanneries that
  used to be clustered around the New York City
  area are long gone. No longer is a
  practical-trained old tanner going around in his
  high boots with his secret formula book tucked in
  his back pocket, sleeping beside the paddle at
  night and making sure no one watches as he makes
  his secret chemical feeds. The perishable,
  straight vegetable-tanned, stiff-as-a-board,
  cracky alligator leather made back then is also
  only an old memory. This big undertaking isnt
  inexpensive either. It is truly capital

5

• intensive. Make no mistake about it. Doable,
  yes, but not easy or cheap. It had better be done
  correctly from the beginning if it is to
  succeed--simply a matter of good practice
  combined with good sense. I will provide lots of
  reasons to back up the statement that a good
  exotic leather tannery is a costly project.
• What follows are my personal opinions of what
  it would take to establish a long run
  sustainable, modern exotic leather tannery. I
  suppose it is possible to cut corners to reduce
  the initial capital requirements. People have
  created small-scale tanneries with minimum
  investment. But to really establish something
  capable of competing with the existing large
  foreign manufacturers, my philosophy is that
  making the larger initial investment and
  commitment is the only safe route to long-term
  success--high volume, high quality output,
  efficiency, optimal operating costs and long term

6

• profitability. I will propose for you now,
  requirements for a facility whose owners could
  boast about and be confident of and proud to show
  off to their customers and community both the
  plant and the top quality products it produces.
  Exotic leather making today is more science and
  engineering than art and should be approached as
  big time or not attempted at all. Here is how I
  intend to approach the subject
• Starting with some remarks about the project as a
  business
• I will proceed to talk about the physical plant
  and what it needs to contain
• A few words about staffing
• The raw material
• Some equipment comments
• Discussion of the major special steps and
  critical components of actual exotic leather
  making

7

• Finally, some remarks and opinions about
  marketing and business prospects
• FEATURES AND REQUIREMENTS OF AN ALLIGATOR
• LEATHER TANNERY
• Business Plan
• First of all it is a business. That means it
  requires the same thoughtful advance preparation
  that any business does. A detailed
  well-researched, all-inclusive and documented
  business plan has to be completed before anything
  else is done. The plan should cover all the bases
  including capital requirements, key employees,
  marketing plan, site selection, facilities
  design, operating cost and cash flow projections,
  etc. The plan has to be realistic and provide for
  worst case as well as best case scenarios. Only
  when a complete business plan has been written
  and analyzed and extensively challenged

8

• and proven viable, should an entrepreneur or
  entrepreneurial group consider proceeding with
  such a project to the next step of raising
  adequate necessary capital.
• The Physical Plant
• The site should be both accessible for trucking
  traffic and isolated from other facilities.
  Structures should be sturdily built and easy to
  maintain. They should be planned with sufficient
  interior space and utilities to provide room not
  only for relatively small starting production,
  but plenty of room for future expansion needs. It
  is much easier to plan for eventual growth than
  to try to squeeze more production into an already
  filled area.
• Ample, even abundant fresh water availability
  is a given, of course. In a hot climate location
  such as here in Texas, if the incoming supply
  water temperature is elevated during the

9

• hot months, a water cooling arrangement is
  highly advisable. And of equal importance at the
  other end of the water flow circuit, is some kind
  of effluent-accepting and treating system to take
  the process waste stream that will be generated
  and prepare it for discharge to a (POTW) or the
  environment. The site itself should be large
  enough to accommodate whatever effluent storage,
  equalization and on-site pretreatment plant is
  called for.
• At least primary or secondary effluent
  treatment systems will be necessary. Their design
  and operating cost has to be incorporated into
  the plan. Efficiency in process design and
  control (recycling and optimal flow rates etc.)
  will contribute to minimizing costs of the waste
  treating system design, installation and
  operation. The design will need permitting and
  approval by the district and state authorities.
  All this should be in the hands of a good
  consulting engineer

10

• or engineering firm. Realistic estimates of
  these engineering costs must be part of the
  business plan.
• Chemicals and equipment used in any tannery
  present plenty of hazards, so it is necessary to
  have a complete safety plan that complies with
  OSHA and local regulations from the outset. That
  includes piping and drains designed to segregate
  low and high pH streams to prevent toxic gas
  (I.E. H2S, SO2, Cl2, etc.) generation and
  emission. Much preferable to have the engineers
  do this in the planning stages than have to retro
  fit them into your facilities afterwards (or to
  experience terrible accidents as have happened in
  tanneries in the past where improper attention
  was given to these details!).
• Exhaust systems of suitable capacity for
  ventilation, finishing spray booth vapors and
  possible toxic gas removal, are necessary. The
  exhaust system will itself need to comply

11

• with VOC and EPA or DEQ toxic emission
  standards. This is just another reason why such
  plants need to be in isolated locations. What I
  have addressed so far applies to almost any
  tannery, not only exotic plants.
• Exotics Plant Specifics
• Now Id like to discuss some of the specific
  needs of an exotic, particularly alligator and
  ostrich skin, tanning facility.
• Receiving Area
• The first part of the plant has to have a
  suitable place where the salt-cured or green
  skins are received. It can be outdoors, but under
  sufficient strong cover to protect the area from
  the elements. Indoor space is preferable.
  Forklift access is necessary, here. Provision for
  counting, inspecting, examining, measuring and
  recording tag numbers for the arriving skins is
  important. The area needs good lighting and
  airflow.

12

• Inspecting Area
• A sturdy inspection table with a glass top back
  lighted from underneath and etched or painted
  with cross hatching by inches and centimeters can
  easily be built to be used for Checking incoming
  shipments and avoid disputes with shippers. Large
  quantities of curing salt accumulate at the
  receiving table. Since salt is such a difficult
  contaminant to remove from any effluent,
  provisions have to be made to collect as much of
  it as possible for separate disposal while still
  in the solid condition.
• Hot Water Production
• The plant will need a modern, maximum efficient,
  recirculating hot water heating system of which
  there are several excellent direct gas-heated
  models available. Piping throughout the plant is
  critical. Design pipe line installation

13

• to protect against incoming water freezing in
  winter or heating in summer. It is also important
  to avoid any possibility of backup from hot water
  supply lines into any cold water lines. To insure
  this, design proper check values and double
  shutoff value systems into the piping.
• Beamhouse Solids Collection/Processing
• In the beamhouse area of an exotic tannery,
  considerable amounts of low-density solids are
  generated and deposited into the effluent stream.
  An efficient, mechanical filter system to
  separate and collect these solids and remove them
  from the effluent stream before it enters the
  waste treatment plant is another important
  component By reducing sludge entering the
  treatment system, this will both simplify
  disposal of the solids and allow the treatment
  system to operate at maximum efficiency. The
  outer protective keratin layer of exotics, of

14

• course, is in the form of scales and quills, not
  hair, as in other leather making substrates.
• Pitched Floors
• Floors need to be pitched away from process
  vessels toward some form of drainage ditches
  which, in turn, need to slope toward a large sump
  collector outside the building, from which the
  effluent can be pumped to the treatment system.
  The ditches need to be adequately sized for
  maximum anticipated flow out of the processes and
  equipped with covers able to support forklift
  traffic. Floors need acid-and alkali-chemical
  resistant surfaces along with plenty of toughness
  for forklift and other wheeled equipment traffic.
  Installation of one of the many available modern
  flooring surface treatments with these properties
  during original construction will pay off in the
  long run built-in surface flushing lines to
  maintain sanitation and

15

• cleanliness go into the starting construction.
• Wet End Processing Areas
• With the basics of the facility now in place, we
  can address some details of the separate
  operating areas that it should contain.
  Obviously, a wet department for the essential
  processing has to occupy a sizeable portion of
  the structure. First an area needs to be provided
  where workers can clip skins, count, record
  tags and weigh them into predetermined
  formulation batches for processing. It is
  desirable to arrange a segregated area for each
  of the wet departments the beamhouse, pickle and
  tan section, and retan and coloring area.
  Although it is possible to do pickling, tanning
  and coloring in the same vessel, it is much
  preferable for quality control as well as
  equipment scheduling and maintenance to have
  separate reactors dedicated to retanning and
  coloring. At

16

• the start of a facility, a minimum of full sized
  processing vessels will suffice. However ample
  floor space should be designed for plenty of
  additional units when production demands
  eventually grow. This is much preferable to
  having to squeeze extra vessels in when they are
  needed.
• In-Process Holding Area(s)
• A generous space nearby the production
  processing vessels, using the same drains, needs
  to be set aside for a pilot plant with
  various-sized miniature vessels to do process and
  product development, color matching and small
  order processing. To attain and retain the high
  quality standards always required by the end
  users, and to develop interesting new products to
  retain market interest, it is important to have
  continuous product development work on a pilot
  scale.

17

• Chrome Liquor Capture
• Advance provision for capturing spent chrome
  liquors (yes, at least partial chrome tanning is
  pretty standard for producing quality exotics
  today), before they can mix with any other spent
  streams, will allow for chrome recycling or
  chrome recovery techniques. However, that would
  not preclude designing the tanning process itself
  for maximum chrome exhaust.
• Mezzanine Level Access
• A mezzanine above the process vessels,
  accessible to forklifts, is not mandatory, but it
  is a great help for preparing and batching,
  weighing and making formulation chemical feeds. A
  storage area where liquid and solid chemicals can
  stay dry, be received and kept separate is a
  must. Hazardous materials should be isolated from

18

• non-hazardous, of course, in a separate section.
  Simple cleanup of that area should be built in.
• Drainage
• Generous drain-connected holding spaces for
  storage where goods in process can drain excess
  liquors while reaching equilibrium between
  operations are needed.
• Process Analytical Lab
• Convenient to the wet departments, at least a
  minimal lab for process controls (pH, Be/, etc.)
  is a must. In a separate part of that area,
  dyestuffs and samples of chemicals can be kept
  and precision weighed or measured. Somewhere
  close to the coloring vessels a very well lighted
  area, with modern daylight color-corrected lamps
  and a modern color-matching booth large enough
  for display of whole skins, is required. It
  should have a small dryer set up close by for

19

• process sample checking for coloring, finishing
  and ready to ship color matching.
• Moisture and Dust Control Measures
• Mechanical operations such as fleshing, shaving
  and buffing require their own closed off space
  with ample air circulation and provisions for
  gathering and removing the solids generated by
  the operations. Effective shaving and buffing
  dust collection is extremely important. The dust
  must not be able to escape from the area where
  they are created. You cant have dust floating
  around finishing department of a quality
  producing exotic plant any more than in a
  conventional tannery. Dust particles are
  particularly destructive to glazing. Drying
  technique makes a major contributor to exotic
  leather quality. There are numerous approaches to
  accomplish good drying. Plenty of space

20

• has to be allocated to drying space. There are
  likely to be at least three separate dryings
  during the course of exotic processing--crust,
  color, finishing.
• During drying before finishing, the skins
  should always be in a stretched condition.
  Something as basic as manually tacking out the
  skins onto plywood (usually done today with heavy
  duty staple guns, using only stapes that will not
  react with and stain the wet skins), and leaving
  the boards stacked in a loft until drying is
  uniform and complete, works well. But it is very
  labor intensive. More recent automated toggling
  or vacuum drying devices can also be used. They
  cost a great deal more, but for eventual higher
  volume production capability they should be
  carefully considered with space allowed for them.
  Whatever is the method of choice for stretching
  the skins, the uniform circulation of low
  temperature (not much above ambient), low
  humidity,

21

• turbulent air in the system is critical to the
  result. Low temperature, low humidity conditions
  are what produce the slow uniform drying
  necessary to prevent shrinking and produce
  desired soft leather out of the dryer. Drying is
  of key importance so each tanner should very
  carefully evaluate it during planning. A space
  requirement that might be overlooked is a nice
  clean area for conditioning crust skins after
  drying. A slightly raised platform to provide air
  circulation from all around the piled skins is
  ideal. Enclosing the crust area with a protective
  curtain sort of like a hospital bed arrangement
  would be a plus. Drying after finish coatings can
  be done without stretching. If some kind of spray
  machine is installed (any consistent high-volume
  quality producer ought to have at least one
  single-stage unit), its conveyor will be
  connected to a dryer of one type or

22

• another. There again the drying should be slow
  and air circulation needs to be emphasized over
  higher temperatures. Finish coatings on exotics
  are very thin coatings that will dry relatively
  quickly if exposed to high volumes of only mildly
  warmed air. Keeping the humidity down is still
  very important. Good exhaust with proper
  filtration and scrubbing to prevent vapors going
  into the atmosphere will have to be demonstrated
  before a plant can get permitted. Water-washed
  booths are expensive, but, if well designed, can
  help prevent lost of exit air quality problems.
• Finish Application and Final Drying
• A hand booth can also be used for applying the
  finish coatings. The same exhaust requirements
  apply here. Hand spraying is difficult to control
  for complete uniformity and requires a skilled
  operator, is tiring and slow from a

23

• production viewpoint, but it does contribute
  some of that hand-crafted look to the final
  product. Hand sprayed finished skins can be
  simply hung up between coats and left to dry with
  good air circulation. The dryer can be as
  elementary as a series of stretched close-lines.
  Obviously that is quite crude, and cheap but it
  works. It consumes considerable floor space. A
  much preferable arrangement employs some kind of
  a moving chain stick dryer arrangement where the
  conveyorized slow-moving sticks pass through an
  enclosed heated tunnel dryer before returning to
  the spray booth ready for the next spray coat.
• One area that, for obvious reasons, has to have
  cleaner air and surroundings than any other place
  in the plant is the glazing room. Design should
  anticipate those conditions along with plenty of
  room for the piled skins ready for

24

• glazing into so-called classic alligator
  leather.
• Dry milling is used with exotics just as with
  conventional leathers, so a really dry space
  where the skins can easily be loaded into the
  unloaded from the mills is another requirement.
  Here again, a forklift accessible mezzanine from
  which the skins can be loaded into the dry mills
  is nice to have.
• Mechanical/Maintenance Shop
• Last, but by no means least, is the need for a
  maintenance shop where equipment for keeping the
  plant and its contents in good condition can be
  kept and used. It may not be practical because of
  low volume usage and high cost, but it would be
  great to have facilities for reblading the
  various cylinders used in the different machines.
  Special sized cylinders with different space
  between blades and different

25

• blading angles are required for exotics and it
  can be a problem constantly having to send them
  to outside contractors for reblading and waiting
  for their return.
• Shipping Area
• All the work of the plant culminates in the
  shipping room. This requires a spacious, well lit
  (some natural light is preferable, the artificial
  lighting should be color corrected), clean, dry
  area. It will need provisions for final grading,
  color checking against standards, smooth-topped
  tables for alligator measurement, tag recording
  and packing equipment. For the larger skins of
  Ostrich, including space for a simple modern
  measuring machine on which skins can be fully
  extended, is not just a very good idea, it is a
  necessity.
• Security and Worker Conveniences
• It is important not to overlook provisions for a
  plant security

26

• system that will protect against the various
  specific hazards that are inherent in exotic
  processing in addition to the usual problems from
  fire, theft, sprinkler failure, excess interior
  temperature either high or low, hazardous gas
  emissions, etc. Having motivated good employees
  is vital. Their needs should be built into the
  plant in the form of ample wash and rest rooms,
  dressing and showering areas and a well
  ventilated eating area. Provisions for both
  genders and the handicapped will pay off and
  round out a proper facility (and, most likely, be
  required for permitting).
• That pretty much covers the physical plant. I
  have tried to include lots of very practical
  details that only experience makes one aware of.
  My pointing them out in advance to anyone
  contemplating this kind of venture will help save
  them from lots of later grief, if they heed my
  advice.

27

• Staffing, Personnel and Job Responsibilities
• Now let me say a little about staffing. What I
  have given you so far is a picture of a complex
  operation. It needs some good people to handle
  all the details. Responsibilities should be
  divided among several trained individuals.
• Owner/Principal
• The principal entrepreneur carries overall
  responsibility and authority, of course, but that
  person should not attempt to be expert in
  everything. He needs to hire some good key people
  and hold them responsible for performance in
  their assigned part of the operation. Although it
  is good for the entrepreneur to have at least
  some understanding of the various special
  details, micro managing does not work very well!
  Responsibility for managing completion of all
  the preliminaries of planning, financing,
  constructing and

28

• equipping the facility belong to the
  entrepreneur. Also, normally, he or she will be
  responsible for
• the negotiations for purchasing skins
• establishing market connections
• pricing of the products
• setting compensation and benefits
• banking
• community relation
• approving contracts
• partners or Board of Directors and stockholder
  and investor relationships
• overall financial arrangements including
  necessary borrowing for the business

29

• Plant Manager/Tanner/Leather Engineer
• Second in command is the plant manager/ tanner
  /leather engineer who is responsible for running
  day to day operations and production as well as
  making the product, while the operation is
  growing. When and if the operation grows to a
  size that warrants it, this function should be
  subdivided to production and process. (When and
  if the size of the operation warrants, a colorist
  and finisher can be added to work under the
  tanners supervision.) The position calls for
  someone with thorough knowledge, understanding
  and experience of tanning and tannery operations
  from raw material to finished product. Leather
  know-how is very important. In addition, the
  person selected needs a chemistry or chemical
  engineering education. If not in the US, people
  with all the

30

• needed qualifications have been educated and
  should be available in other countries--Mexico,
  Canada, England, Italy, Spain, France, Germany
  and Japan are among the potential sources.
• Ideally, the person would be experienced with
  exotics, but that specialization can be acquired
  by the right individual as long as there is a
  solid grounding in all aspects of tanning
  including everything from raw material to
  finished product. This position will be
  responsible for training of workers in the plant
  in the various process operation requirements. It
  would be very helpful if he or she has good
  mechanical skills. However, another individual
  will be responsible for the mechanical
  operations. (Notice all along that I try to avoid
  use of the male pronoun because there are women
  today with equal qualifications for all these
  positions.)

31

• All processes, formulation writing, scheduling,
  record keeping, ingredient specification and
  purchasing, quality and process controls, problem
  solving, product development, color matching, lab
  work, standards, equipment selection etc. will
  originate at this desk. Because so much of the
  potential success or failure of the project will
  depend on this position, great care is needed in
  choosing the right person. Overall compensation
  package has to be competitive and sufficient to
  assure that the future of the operation will be
  in the hands of someone who can be trusted to do
  the job properly.
• Plant Mechanical Engineer
• The third key person handles the mechanical
  processes and the plant machinery. When the
  operation is small this person should be
  qualified to set up and run the various
  mechanical operations and also maintain the plant
  equipment. If it is

32

• only possible to find someone with all-inclusive
  general maintenance know-how, that is the more
  important skill for the position. The best thing
  is for the mechanical person to be fully
  qualified to setup, wire and maintain the
  machines and operate them during the low
  production start-up period. Actual machine
  operation can be taught to good hands workers
  by outside consultants well enough so that the
  selected workers will develop production skill
  for running the machines. This key person will be
  on board early to help supervise the construction
  then place and install all the equipment. Once
  the plant is operational, this person will
  supervise machine production and operators,
  conduct preventative maintenance, and do whatever
  repairs are required over time (or arrange for
  outside assistance when necessary).

33

• Administrative Assistant
• As in any other operation, a versatile office
  person will be key to proper record keeping,
  computer functions, reception etc. The office
  person will perform the essential duties of
  comptroller plus record keeping, communications,
  billing and payroll. This position will be
  responsible for liaison with the obligatory
  outside CPA firm.
• Little-known Ingredients for Success of the
  Exotic Leather
• Tannery Raw Materials and Marketing
• Raw Materials
• Today, a significant sized exotic tannery will
  principally process raw material raised on farms
  or ranches. That is the only way to plan stable
  production, be able to supply orders in a
  dependable way, and be assured of controlled good
  quality input. All my discussions today are based
  on that

34

• kind of raw material. Supplies are not always
  uniform throughout the year, but with good
  planning and sufficient capital available to take
  advantage of best markets, raw material can be
  stockpiled. This is a main reason why large
  well-designed cooler space is required.
• Stock that is properly cured and PROPERLY
  stored can be held long enough to smooth out the
  seasonal ups and downs of supplies from the
  farms. Larger cooler space makes it easier to get
  at the oldest raw material so that production can
  be on a first in, first out basis to minimize
  storage time. Larger skins from annual wild
  hunting or nuisance animal kills can be worked
  into production schedules as fillers. They will
  not be the main production as a general rule.
• There are specific characteristics of the
  exotics--

35

• alligators, ostrich, lizards and snakes--that
  distinguish them from the more conventional
  bovine, sheep, goat and pig species. The outer
  keratin protein layer (which on other animals is
  in the form of hair) occurs as claws, quills and
  scales. That, plus their irregular shapes and the
  bony horn layers of alligators dictate the needs
  for special handling and equipment in exotic
  processing.
• As far as shape goes, gators taper down to
  quite narrow width in the tail and the legs
  attach in a way that does not allow them to lie
  completely flat. This makes it tricky when it
  comes to fleshing and shaving. Some foreign
  processors cut the legs off completely making
  handling easier, but doing that removes some very
  attractive leather from the skin and every part
  eventually has to be fully utilized. Alligators
  require very narrow cylinders and cylinder
  blading. Much care is needed to avoid nicks and
  cuts and

36

• make it possible for the operator to get into
  all the nooks and crannies. Multiple passes by a
  skilled operator using foot control against a
  narrow cylinder seem to be the only approach for
  handling this properly. With larger, thus
  thicker, skins from the controlled annual wild
  animal hunts, a somewhat wider cylinder can be
  used, but splitting is not practical for reducing
  the thickness to proper levels.Here there is a
  big difference from handling larger stock like
  cattle hide on large automatic shavers and
  splitters. Ostrich has to be handled so that the
  quill shaftways do not open into holes. Quill
  sites should end up raised and prominent to
  produce the characteristic ostrich look, but they
  cannot open up raised and prominent to produce
  the characteristic ostrich look, but they cannot
  open up into holes that light can pass through as
  with lace curtains.

37

• But once the above differences are compensated
  for, the leather-making components consist of the
  same collagen protein that reacts to the basic
  tanning chemistry other leather making substrates
  do. Thus, in my opinion, the real secret of
  tanning good exotics lies in the application of
  good standard leather making chemistry. Incoming
  raw material, unlike cattle hide, has to be
  carefully checked in, measured, inspected and
  registered piece by piece. This is particularly
  so of alligators which are a carefully controlled
  wild species. Tag numbers have to be checked off
  against incoming manifests. The tags must remain
  on the skins and have to be accounted for all the
  way through to shipment. Any tags that break off
  during processing must be fully accounted for in
  the shipping room. That presents many challenges
  along the way as can readily be imagined.

38

• All ostrich are raised on small family farms or
  very large ranches today. The bulk of commercial
  gators are farm-raised. Gators are harvested at a
  size range of between 3.5 and 6 to 7 feet tops
  (usually closer to 5 feet tops) in length. This
  is the economic point for harvesting, as the
  growth rate declines very sharply after this size
  has been reached. If I recall correctly, this
  corresponds to about 18 to 24 months in age. They
  are traded on the basis of price per foot in
  length, and sold by maximum width measurement in
  centimeters, so there is a premium on width to
  length ratio which varies by the husbandry
  methods of different farmers. That ratio often
  dictates which suppliers are preferred sources.
• Marketing Strategies
• This seems to be a good place for a marketing
  aside. Size and orientation of the hide are key
  to marketability of

39

• the resulting leather. One must pay particular
  attention to these parameters when accepting and
  specifying raw stock.
• Originally, before gator farming, when all
  skins came from the wild, there was no uniformity
  of size and most skins were much larger than from
  todays farm-raised animals. It took sometime for
  the buyers to accept the smaller range of skin
  size because patterns were based on much greater
  cutting area. However, first of all, the skins
  from the wild had lots of grain damage from their
  natural living conditions, fighting, scratching
  against objects etc. Farmed skins are normally
  almost free of those defects. Secondly, the tile
  size grows with the animal. So the wild skins
  have quite large tiles. In any given cut panel,
  there is much less tile pattern showing than for
  the same panel cut from smaller skins where the
  tiles are much smaller and much more numerous
  within the same area.

40

• Sometimes in a completed belt made from large
  skins, for instance, all that is visible from the
  tile pattern is a few vertical lines. This little
  key fob that I carry is a good example to
  illustrate the point. It would be easy to cut a
  complete piece of this size from the center of a
  single tile of a large animal. No pattern at all
  would show. It would appear just like a piece of
  leather from an unidentifiable source. Once the
  cutters recognized that small skins resulted in a
  prettier and more interesting look where it was
  much easier to recognize the source in the
  finished product, the smaller, cleaner skins
  became the norm. Some skins may be received green
  (not cured) if a farm happens to be really close,
  but by and large they need to be fully cured with
  NaCl. Pretty much standardized today is shipment
  in boxes with raw gator skins rolled grain side
  out. Excess salt has to

41

• be shaken off before inspection. That salt needs
  to be collected for disposal or reuse (if it is
  clean enough). Of great importance in both types
  of skins is the takeoff. Only an absolute minimum
  of flesh (adipose tissue) is acceptable in both
  cases. However, there is a fine line to be drawn
  here, because it is possible to damage inherent
  fiber strength if the takeoff goes too deep
  beyond cleaning the adipose tissue from the flesh
  side.
• Well-presented stock has clean, almost pure
  white backs with little or no hanging yellowish
  pieces of flesh present, no knife cuts and little
  or no odor. The black or brown and white
  variegated coloration of the tiles actually looks
  quite attractive in the raw state when the boxes
  are opened. That coloration disappears during
  standard processing, although a completely
  different product still showing much of it is
  possible with

42

• substantial changes. I will not attempt to
  elaborate on that here.
• Ostrich should have few to no quills when
  delivered and no knife cut holes. Skins that come
  from the larger ranches are usually well handled
  today, but the smaller suppliers have been known
  to deliver skins heavy with very undesirable,
  sometimes already rancid, fat, even meat chunks
  and enough feathers to look like feather dusters!
  By now suppliers should be sophisticated and
  skilled enough to deliver properly flayed skins
  in both of these major exotic categories. It is
  up to the tannery to insist that they will only
  accept deliveries that are.
• Only a very minimum , if any, of 3 grade
  alligator skins are acceptable in a quality
  shipment. Any shipment with higher quantities of
  3 grade should carry an agreed price way below
  market and be designated to be made for

43

• reduced-price, specifically contracted orders.
  Inspection on the back lighted table described
  earlier for alligators will reveal some not easy
  to spot flaying knife cuts (experienced farmers
  or packers use air knifes almost exclusively
  today, so cuts should be rare), holes and
  scratches or scars that penetrate beyond the
  surface of the scales. Excesses of any of these
  defects will cause a skin to be downgraded to a
  3 grade. This is where the defects have to be
  caught. The tanner who is not sufficiently
  diligent in his receiving inspection will only
  have to pay for that mistake when he has to
  downgrade the skins in the shipping room. Buyers
  reject from their receiving inspection will only
  have to pay for that mistake when he has to
  downgrade the skins in the shipping room. Buyers
  reject from their receiving inspection any low
  grades not specified in their order contracts.

44

• At this point it is well to note that there are
  two distinct presentations for alligator skins,
  back cut and belly cut. More conventional has
  long been the back cut, cut down the centerline
  of the back. This skin, lying flat, has a row of
  horns running along the length of each side with
  the belly whole and in the center. Those horns
  have in the past been trimmed off and used for
  special end products. In more recent years, a
  market for belly cut skins has become popular. In
  this case the cut is made down the length of the
  belly. This skin has the complete array of horns
  in the center with a belly strip along each side.
  The cut produces what is known as hornbacks. It
  does not lend itself easily to glazed classic
  finish, but can be made into very interesting
  mellow softee products that have shown
  considerable demand by some specific markets like
  many of the boot and belt makers.

45

• Equipment
• Id like to say a few things about the equipment
  in the plant I have been discussing. Weve talked
  about things like instantaneous hot water
  heaters, inspection tables, fleshing and shaving
  machines and dryers. I direct your attention to
  processing vessels, shaving machines, glazing
  equipment and dry cleaning, yes dry cleaning
  equipment.
• Drums and Processing Vessels
• Regarding the main vessels for processing, all
  I can say is that in this day and age there are
  lots of goodies available with all kinds of
  choices. Some good stuff is still manufactured in
  the states but a far greater variety of
  innovative vessels is made in Europe and
  elsewhere. Drums and paddles constructed of
  exotic woods, fiberglass and stainless steel are
  available. Some are belt, some gear driven with
  or without RPM and rotation

46

• reversibility. Some require concrete
  foundations, others have wood and still others
  come with steel mounting framework. They can have
  interior Y compartments, shelves, stationary or
  moveable baskets inside or different sizes,
  numbers, shapes and composition of pegs
  distributed on the walls, and all kinds of access
  ports and door construction and location. Even
  variants on the so-called hide-processor design
  (cement-mixer configuration) are widely used.
  Many different mechanisms for wet and dry
  chemical feeding, filtration, re-circulation,
  interior mixing, float volume measurement as well
  as continuous pH and temperature monitoring are
  offered.
• I have worked with a number of different styles
  and made satisfactory product using all of them.
  I suggest some time be spent investigating the
  different varieties, if possible, at one or more
  of the big international leather shows where many
  competing products are on view to be compared.
  Significant

47

• considerations for this part of a new plant plan
  (other than the size of the original capital
  outlay) are
• Simplicity and effectiveness of design
• Ease of operation and maintenance
• Chemical resistance
• Predictable durability inside and out
• Rugged ability to withstand tannery environment
• Reliable access to spare parts
• History of the manufacturers dependability in
  supporting his product
• Gentle action on the delicate exotic skins during
  processing
• Capacity
• Personally, I prefer tilting paddles constructed
  of heavy-
• duty fiberglass with built-in drainage and
  reversible paddle
• wheels for the so-called beaming processes.
  Large

48

• PVC piping to deliver high water volume quickly,
  needs to be provided. It is absolutely vital that
  such piping can be pulled out of the paddle when
  it is charged with skins so there is no way for
  possible hot water drips to enter the paddle
  during the long process. Equally important here
  are check valves and double shutoffs to guard
  against unintended hot water intrusion. Variable
  speed timer-controlled paddle wheel drive system
  is highly desirable. The paddle wheel is not only
  gentle, but it gives excellent mixing. Paddles
  permit continuous observation of the progress of
  the process as well as sampling for controls.
• For pickling, tanning, retan and coloring I
  would select for my ideal a rugged heavy duty
  wood or even fiberglass
• construction with all the fixings that could be
  expected to

49

• hold up over the years
• Solid construction with components that could
  withstand the highly acid conditions to which
  they will be exposed is mandatory. You dont want
  to be caught replacing one of these babies every
  couple of years, believe me.
• Interior fixed or rotating Y-shaped baskets or
  similar devices
• Door systems and wash ports that not only seal
  tightly, are easy to open and close, dont pose a
  major health problem for the backs of operations,
  and can readily be repaired after use, are
  important factors in the selection process.
• Drives controlled by a dependable timer that can
  reverse rotation direction and set rotation at
  very low RPM are what I would recommend.
• With all the innovations available today, I
  still have to
• remind myself that good old solid wood drums have
  often
• outlived the tanners who used them!

50

• Shaving Machines
• Used small cylinder shaving machines suitable
  for exotics may still be found around the US.
  However, for new machines, I think one has to
  turn to Germany or Italy for sources. This is
  another reason for attending tanning machinery
  shows during the planning stages of a new plant.
• Glazing Equipment
• Glazing jacks present another problem of
  availability from US sources. Small side glazing
  jacks re required for gators. Sources for the
  right size and composition of agates and cut
  straps for these machines are not easy to find.
  But they do exist. An ample supply should always
  be kept in stock to provide for time delay
  acquiring replacements. The same applies to
  suitable leather bed straps for these machines.
  These are little but quite important details to
  take care of.

51

• Degreasing/Dry Cleaning
• One expensive piece of equipment that belongs in
  the kind of tannery I have been talking about is
  an automatic dry cleaning machine. Not everyone
  will think of including this. Woolskin and sheep
  tanneries are probably the only other places
  where dry cleaning to remove excess fatty
  material is necessary and utilized. It can save a
  lot of grief in the processing of alligators and
  ostrich in particular. Let me add a word of
  caution on upkeep of this machine. It is likely
  to be the sole source of volatile solvents in the
  entire plant. To avoid problems with effluent,
  the dry cleaning machine has to be totally
  isolated from any possibility of spills into the
  waste water system. When it is cleaned, when the
  filters are flushed, all the time, anything
  liquid that comes out from the machine has to be
  totally captured and not allowed to contaminate
  any other waste. Spent solvent must be disposed
  of separately by

52

• solvent recovery or as permitted hazardous waste
  by licensed haulers--no shortcuts in this area at
  all!!
• At the start of my presentation I cautioned
  that a good, modern exotic tannery requires a
  good deal of capital to set up. It should not
  require any fancy computer spread sheets to come
  up with a quick estimate of the cost for what I
  have outlined so far amounting to some pretty big
  bucks--and thats without even considering
  processing or inventory costs!
• Secrets of Exotic Leather Manufacture Critical
  Processing
• Strategies
• Now Ill discuss a few process key points that
  you have been patiently waiting for me to get
  around to. Please dont expect me to present you
  with a recipe for making alligator or ostrich
  leather, because that is not my intention. But I
  will

53

• pass along a number of the critical things that
  contribute to making good exotic leathers. The
  process methods I will describe really are
  intended for alligators. That is where I believe
  the supplying industry has developed the most
  stable quality raw material sources as of now. A
  steady flow of good raw material, necessary for
  production planning, can be counted on from the
  alligator farms. Ostrich ranching here in the US
  is not far behind. Most of the basic chemistry
  for alligators will also work for ostrich, but
  ostrich pelts are not quite as delicate to
  handle.
• Things that are different with alligator and
  ostrich processing than with cattle hides are,
  for example
• batch size
• time in process
• precision of quality-control measurement.

54

• When I first realized the number of exotic units
  considered a decent months production volume, I
  remember saying Wow, most of the other plants
  Ive worked in produced a much higher number of
  units than that before the morning coffee break
  on any given day. Each piece was much bigger,
  too!
• This merely emphasizes the high value of each
  skin going through an exotic plant, and why that
  brings about a need for even greater caution and
  tighter quality controls in all the handling
  stages. At various points in a bovine plant,
  there are trimming operations where
  machine-caused hanging pieces and animal defects
  are cut off. When you are dealing in centimeters
  of width measurements, as you are with gators,
  great machine operator skills are vital to
  prevent ragged edges requiring trimming. And
  upgrading had better be accomplished in the
  receiving department by rejecting poor

55

• quality skins at the back lighted sorting table!
  Scales on gators allow most defects to be seen,
  but the hair on raw cattle hides does not.
• When a formulation calls for grams per liter
  and the liquor is supposed to have a designated
  specific gravity, the Baume/ as well as the
  temperature need to be precisely within the
  specified ranges. If only so many turns or
  minutes of paddling or drumming are specified in
  the formulation, that is what has to be followed,
  or else the delicate grain layer may be scratched
  or otherwise damaged. The value of the skins
  making up any given batch is too high for any
  casual execution of formulations. (Casual or
  careless attitudes have been known to almost
  result in some other kind of executions when an
  irate tanner became overly provoked!!) It is
  important to remember that during the early
  stages of the process, the temperature sensitive
  purified collagen protein

56

• will degrade into gelatin just as in the gelatin
  and film making business where the starting
  product collagen is subjected intentionally to
  elevated temperatures. If hot water contacts the
  skins before they have been made thermally stable
  by tanning crosslinkages, they can gelatinize
  irreversibly! That is a real tannery disaster
  possibility needing means of prevention at any
  cost!!
• Things move more slowly through an exotic
  tannery than through large bluing plants or upper
  leather tanneries. In the early stages of the
  process things cannot be rushed. Formulations
  have to have time flexibility built in to allow
  for close inspection of the progress of each
  operation to determine if the proper end point
  has been reached. If not, then whatever
  additional time is needed has to be added. It is
  not always possible to say this goes in today and
  comes out at a specified time tomorrow. Sometimes
  a batch may require

57

• another day or even more so that is what it has
  to get. If the cake is not ready, leave it in the
  oven! This would defeat a modern production
  bovine plant, but it is just one of the things
  that will separate a successful exotic plant from
  that other mode.
• Think of natural fat as the enemy. It must be
  eradicated as early and as completely as
  possible. Fats can block penetration of and even
  react with tanning and coloring ingredients. Fats
  will show up in the finished product in the form
  of color difference, stains or surface dullness.
  They raise all kinds of headaches on products to
  be glazed. For all these and other reasons,
  appropriate degreasing efforts have to begin with
  the very first soak and continue through the wet
  processes. And, later in the process, topping it
  all off, any residual natural fats still in the
  dried crust must be finally extracted in a dry
  cleaning apparatus and then the skins should

58

• look absolutely clean, beautiful, stain free and
  ready for finishing into fine leathers.
• That old tanners line that leather is made in
  the beamhouse is nowhere more true than with
  exotics, so I will now discuss some specific
  control points for modern exotic skin beaming
  procedures.
• Soaking and Scouring
• First of all, to achieve best possible fat
  removal, I suggest a presoak followed by a wash.
  Overnight main sock with brief intermittent
  paddling, fleshing to clean off any adipose
  tissue and create a very smooth back surface,
  then weighing to establish a new formulation
  basis for the subsequent wet operations follow.
  And after that I still suggest an additional
  2-day degreasing soak with occasional brief
  mixing. In each case, of course I suggest
  incorporation of good biodegradable surfactant
  detergents, LOW concentrations

59

• of appropriate enzymes, and approved
  biodegradable biocides into the bath. The skins
  should be pulled after this soak so the descaling
  bath can be prepared. As you can see, there is a
  lot of extra handling involved here and that all
  contributes to the high cost of exotic
  processing. It also contributes to high cost by
  adding to the overall process time during which
  inventory capital has to be covered.
• Descaling
• The descaling bath has to be prepared before the
  skins are loaded because Sulfide
  (Na2S)/Hydrosulfide (NaSH) solubilizing produces
  an exothermic reaction. It has to be prepared in
  advance into a concentrated approximately 20 Be/
  solution that then is allowed to cool and then
  measured and added to the paddle liquor until the
  desired Baume/ and temperature is set. Some
  Calcium Chloride to control rate of

60

• swelling and, once more, some surfactants
  should be mixed into this bath before the skins
  are returned to the paddle. After the first 24
  hours with periodic brief paddling, the
  de-scaling should be nearly complete, the skins
  now opaque and nicely plumped. On second day the
  paddle should be recharged with about a fifth of
  the first days sulfide charges.
• Liming
• Once the scales are completely off, a small
  quantity of powdered lime Ca(OH)2 is added to
  help with removal of the epidermal layer (amount
  is calculated as grams of powder per liter of the
  combined total volume of Sulfide solution
  previously used). A brief mixing, then
  intermittent, brief paddling overnight follows.
  Day three is critical to the final product
  quality. A very close inspection of the surface
  is needed now to determine whether or not the
  epidermal layer is completely removed. If there
  is even suspicion that some

61

• might still be present, this is the place where
  it has to be taken care of. Any residual
  epidermis after the complete liming will show
  up as dull areas on the finished product. It is
  too late to try to get rid of it once the skins
  leave the liming bath. To clear any residue, day
  two Sulfide and lime feeds need to be repeated
  followed by another night of intermittent
  paddling. The results under close examination
  should then be pelts absolutely free of any
  evidence of epidermal tissue. The lime liquor is
  drained from the paddle and then several closed
  washes (drain, fresh float, paddle, drain, etc.)
  until pH between 10.5 and 10.7 is attained and
  the skins are quite clean. The skins are left in
  the final wash float overnight with intermittent
  brief paddling and pulled out and allowed to
  drain the next morning, while a deliming float is
  prepared in the paddle.

62

• Deliming
• Deliming is nicely done with Ammonium Chloride.
  The amount used is based on grams per liter of
  the float and again some detergent is included in
  the bath. After intermittent overnight paddling
  (i.e. 5 to 10 minutes every 2 to 3 hours),
  deliming should be complete. The spent deliming
  liquor is replaced with another closed wash at
  temperature slightly elevated to approximately
  85o F.
• Clipping
• Until deliming, the skins are able to slip over
  each other without knotting (assuming the floats
  are adequate and the paddle is not overloaded).
  The balance of the operations create drag and
  friction so, before they can be transferred to a
  drum for the other processes, another key
  caution, each skin must be clipped tail to near
  the front legs to prevent

63

• tie-ups. Without this precaution, it is
  possible, if not likely, that a huge ball of
  skins will develop inside the drum. That will
  wreak havoc with the process and the skins.
  Available are heavy-duty versions of the
  needle-nosed guns like those used to clip tags
  on garments for retail sale. These do a
  reasonably good job, but some will break and need
  re-clipping as the process progresses. As far as
  I know, there is no shortcut machine to do this
  tedious individual skin clipping, but it cannot
  be avoided.
• Bleaching and Pickling
• Bleaching and pickling processes for gators are
  probably where the greatest differences from
  other raw materials are found. This is where any
  residual pigmentation is bleached out and the
  bony substructure under the horns and other areas
  of the skins is softened. It is the slowest part
  of the

64

• process.
• Precautions are
• Handling of the ingredients, which are hazardous
• Monitoring against temperature elevation
• Adequate brine concentrations throughout
• Close pH control
• Stock must be salt brine saturated at pH 7.5 to
  8.0 before the
• undiluted bleaching agent is applied. Sodium
  Chlorite
• (NaCIO2) is a highly effective bleaching agent.
  This
• and the acid feeds that follow it require careful
  training of
• operators in safe handling techniques.
  Hydrochloric Acid
• (HC1) diluted in salt brine is fed separately
  after Chlorite,
• undiluted, is mixed into the skins by brief
  drumming. Using
• HC1 as the acid further contributes to the
  bleaching itself.

65

• The bleaching takes about a day and a half to
  complete with just 2-3 minutes of drumming each
  hour. Once complete skin bleaching is observed,
  dissolved Sodium Thiosulfate is used to kill any
  free chlorine in the liquor. The main pickling
  process cannot begin until starch/iodide test
  paper shows up colorless. All the intermittent
  paddling and drumming operations mentioned above
  will be simple to apply if variable speed
  controls described under equipment are connected
  to the different drives. Throughout these
  processes, operators must show extra respect for
  the potential of contact with dangerous chlorine
  fumes. High volume exhaust needs to be running
  during the entire process.
• Main Pickling
• This process involves slow feeding high
  percentages of HC1 (always carefully diluted in
  concentrated salt brine) spread

66

• out over a matter of hours and then
  intermittently drummed briefly over a period of
  at least 3 to 5 days. Between bleaching and
  pickling, more than 20 per cent of acid can be
  consumed. Daily additions of acid are required to
  maintain extremely low pH--well below 1.0. This
  is continued until the horns are fully softened.
  Brine washes follow the completed pickling and
  the skins are ready for tanning.
• Tanning
• From this stage on, the chemical processes are
  where the tanner can use his or her own formula
  wrinkles and additives to arrive at well-tanned
  skins for which by now they have been well
  prepared and will be fully receptive. Tanners
  experience, his product development results, and
  advice from chemical supplier consultants are
  combined in the balance of the wet processes to
  build the specific distinguishing

67

• character of each tannerys leather into the
  final product. Sufficient chrome to obtain a
  fully penetrated evenly distributed tannage along
  with whatever buffers and auxiliaries the
  individual tanners product development dictate.
  The many different fine chrome compounds being
  offered today can be formulated to produce very
  high exhaust liquors, finishing with a pH 4.0 to
  4.2, even chrome distribution, and high shrink
  temperature. At the completion of the tannage,
  some ecologically friendly antifungal product is
  required to prevent mold growth during storage.
  Typically the tanned stock needs to stand and
  drain for a week before shaving and then weighing
  for retannage.
• Retannage
• Retanning and fatliquoring are combined in a
  separate wet operation for gators. In retanning
  the tanner get another opportunity to exercise
  creative individual know-how and

68

• experience. Combinations of vegetable extracts
  and synthetic tanning agents, straight vegetable
  extract or straight synthetic tanning agent
  retans combined with the appropriate softening
  agents can be worked out to give the different
  leather wanted by the tanner and his customers.
  The right combinations will yield supple, lightly
  colored or pure white stock ready for drying. The
  crust produced will emerge from careful drying
  systems such as described earlier, ready for dry
  cleaning or buffing, and in ideal condition for
  coloring. There are plenty of capable people out
  there in the specialty leather chemical supply
  business who are anxious to offer help in
  demonstrating their auxiliaries, oils and other
  additives for producing the premium products.
• Coloring
• There is little difference between coloring
  exotics that have

69

• outlined and colorin