Leather used in Automobiles The most fundamental question to be answered before you clean or care for leather is to establish the type of leather used in the vehicle and / or finish applied (natural, pigmented, vinyl, urethane coated, and etc) as the methodologies are very specific for each type of leather / finish applied. Using quality dedicated leather products (ones tested within the leather industry) are far more economical as these will always prolong the life of your leather and the need for corrective work won’t be necessary Automotive leather care is a subject surrounded with misinformation and myth. Products such as leather (Saddle) soaps, oil-based Conditioners, Neat-foot oil, and Hide Food still prevail as top sellers, albeit most are made for equestrian tack. These are very different leathers with drastically differing care requirements. The exact reason for this type of misapplication is unclear. It’s possible that there is an association with old world quality (i.e. European automobiles with leather upholstery and real burl wood interiors) with these types of products, despite the fact that the automotive industry has been using water-based polyurethane covered pigmented leather for many years. As materials and production methods that are used change; we need to adapt our product usage and application methodologies to change with them Leather Finishes Leather is a natural product, with a pH of 4.0 and comes from animal (bovine0 hides, which have been chemically processed (tanned) to preserve them. A properly tanned hide (or skin) creates strong, flexible material; resistant to decay. Most leather is tanned cow hide, which are laterally split, rendering an upper (Aniline) and lower cut (By-cast). The majority (95% + ) of automotive upholstery is by-cast polyurethane covered leather, these leathers have aspects of a natural finish, but more uniform in appearance, by-cast will also stretch more than top grain leather and is therefore subject to show creasing. The upper portion is the top-grain, or Aniline, the lower portion is the split or by-cast. This cutting process creates different faces to the leather. The outside face of the top grain shows the natural grain characteristics, but is otherwise smooth, whereas, the underside appears as unfinished or suede The complex tanning process of chromed tanned hides results in the fat liquoring and oils necessary to keep the hide soft and pliable being locked in, the hide is then has a pigmentation coating (a water-based paint) to ensure a uniform colour. By-cast hides are further sealed by a durable polyethylene covering to protect the hide from abrasion from clothing as well as the dust / dirt introduced by the vehicle’s AC system. Leather Upholstery and Trim Surface Identification The most important thing to find out before you attempt to clean or care for something is to ascertain what the material is made from. Much the same is true if you’re trying to remove a stain, what caused the stain and what is the material you are trying to remove the stain from. Formulate a detailing plan, then utilize proper detailing techniques, combined with quality products is what makes a details outcome successful. It is important to be able to recognise the different materials used for vehicle upholstery as some OEM use different materials for the various surfaces (i.e. perforated leather for the seating areas, PVC bolsters and seat backs) Before choosing a product to clean or maintain interior surfaces you must be certain of the material used and wither it is Urethane covered or pigmented Aniline, as the correct care product requirements are vastly different. Once you’ve correctly identified the leather and / or the applied finish applicable to your vehicle's upholstery, it’s easier to select suitable products / methods (one size fits all is just a vendor's marketing myth) To identify the material used; (N-Nubuck / Alcantara®) (A-Aniline / Non-Coated) (P-Protected / Coated) Leather however finished has to allow the movement of moisture back and forth (transpiration) so the use of water- based cleaners and protectors will maintain hydration, which is essential to keeping it in pristine condition. (a) Natural leather (A-Aniline / Non-Coated) Aniline Leather is coloured all the way through with a transparent dye. The effect is applied by immersing the leather in a dye bath. Because the finish is transparent and shows the natural markings of the leather, only top quality hides can be used. It is absorbent and has a random shade colours and grain pattern; lightly scratch the surface to see if it reveals a lighter colour, water drops will darken its colour (temporarily). (b) Protected leather (Pigmented) (P-Protected / Coated) - by slightly scratching it with your nail, if it changes to a darker / lighter shade, it is unprotected (i.e. how suede changes colour depending on the fibres' orientation). If this has little effect it’s protected. If water ‘beads’ on the surface, or if cleaners and conditioners remain on the surface, it’s (polyurethane) protected leather as liquids will not penetrate this type of surface; it will also have an even shine. (c) Nubuck, Alcantara® (N-Nubuck / Alcantara® ) - are top-grain cattle hide leather that has been sanded or buffed on the grain side, or outside, to give a slight nap of short protein fibres, producing a velvet-like surface. Alcantara® is a non-organic (synthetic) material. Both materials are very soft to the touch and will scratch or scuff very easily; water drops will darken the surface, but it returns to its original colour after drying. (d) Nappa Leather (A-Aniline // Non-Coated ) – for leather used in autos, Nappa is a term that is used to denote a high quality leather, it’s a very soft, absorbent full grain (uncoated) and usually tanned with alum and chromium salts and dyed throughout, water drops will darken its colour (temporarily). (e) Vinyl - is a non-organic (synthetic) material that has an even, almost repeating pattern. The depth of the lines within the grain on vinyl is also consistent, while the same lines on leather will vary; it is also usually smooth and soft to the touch. water drops will remain (unchanged) on its surface The common denominator for all the above surface finishes is that they all require specific products in accordance with the finish; not forgetting protection from ultra violet (UV) radiation An extract from one of a series of unbiased Detailing Technical Papers, a library of educational materials that has become the #1 reference for car care on the Internet Chances are you'll learn something about detailing if you read any of these; although these articles will not improve your detailing skills, lead to a successful business or change your life. Applying what you learn from it, however, will. That's where your commitment comes in - you need to make a commitment to yourself right now that you will take action on what you learn. © TOGWT ™ Ltd Copyright 2002-2010, all rights reserved
