>>> I eagerly await your recommendation.
For an unknown stain that has a darkening effect, the stain is most probably penetrated, if so we may be just be looking at the tip of an iceberg.
Approach for such unknown stain is to start with degreasing it with Degreaser-2.2 > Acidifier-2.0 system.
Deeper stain penetration will need the help of Hydrator-3.3 to wick it out to the surface and with a “reverse transfer” technique with a stretchable paper as an extension of the surface the trapped stain is then easily peel off rather than still remaining on the surface.
In most of leather degreasing process especially for penetrate stains, camouflage damaged topcoat is often reveal as a dull surface. When alkalinity is part of the stain, there may be a lost of color to the aniline leather crust. The lost of color to the area can be reactivated and distributed back with Hydrator-3.3 dwelling process with evaporation control with a cling wrapper and leave to dwell up to 72 hours.
Thereafter when dry and erased with Eraser-4 to remove wick up soiling particulates the surface is re-topcoat with AnilineTop-21G.
Tips:
Hydrator-3.3 > Fatliquor-5.0 process may extent to the interior leather lining.
The same with rub-resistant protection using Protector-B for easily slide our feet in and out easily.
Roger Koh
Leather Care Consultant
www.LeatherDoctor.com
[email protected]
Products mentioned are found in this Kit A6.tc, see also kits for other problems from this link:
http://www.leatherdoctor.com/servlet/the-Kit-–-Aniline-Leather-Care-%28Gloss-fdsh-Satin%29/Categories
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Leather Doctor Kit A6.tc – Aniline Leather Topcoat Refinishing Kit
Leather Doctor® Kit A6.tc, aniline leather topcoat refinishing kit is designed for topcoat repairs from friction wear, accidental scratch, scuff and abrasion to deteriorating greasy sweat stains. These topcoat damages are identified as white, dull or darkening stain from bare body contacts. Accidental whitish damages in most cases are free of soiling and direct AnilineTop-21G application with in between dry sanding rectifies most damages. Repairs to topcoat from daily wears that dulls will require a degreasing to remove penetrated rub-in soiling prior to topcoat application in a sequence process including Degreaser-2.2 follows with Rinse-3.0; Hydrator-3.3 follows with Fatliquor-5.0 prior to topcoat application. In a greasy and sweaty topcoat damaged areas especially to the headrest and armrest, a deep degreasing is essential follows with Acidifier-2.0 to stabilize the hydrogen bonding between the protein fibers with the other leather constituent like the tanning agent, dyestuff and fatliquor. This deep degreasing process is assisted by leather Eraser-4 in both the wet and dry cleaning process to remove soiling particulates off the leather surface. Hydrator-3.3 helps in the colloidal water movement bringing suspended soiling particulates to resurface through a dwelling and wicking process. Fat and oil is replenished by Fatliquor-5.0 in an emulsion form to penetrate into the leather structure. Once the fat and oil is hydrogen bond with the protein fiber, the water content breaks free leaving a breathing space for natural transpiration. The fat plumps the leather with fullness preventing the leather structure from collapsing during compressing and flexing while the oil lubricates the fiber from sliding smoothly over one another like millions of connecting hinges. Protector-B+ impart a non-stick, rub-resistant surface with a buttery feel helps reduce friction wear to the topcoat and extended a high level of appearance for a longer period of time. When the leather is contaminated with foreign soiling, it is essential to look at topcoat refinishing in a holistic approach. Note that the cleaning and rejuvenating products suffix denotes its pH value in this leather-safe aniline leathers topcoat refinishing system.