Leather Identification:
Pictures show its aniline dyed leathers, where the natural grain (crust surface) shows through.
The right side of second picture show some crackle effect and it could be a wax pull-up effect as well (pictures from un-used areas, perhaps the reverse side of cushion may help to positively identify it.
Leather identification is important because if the original finishes damages is revealed in the degreasing or stain removing process; products are there ready to rectify it.
General structure for the entire process may consist of the following sequence of steps, but may not necessary to follow through at every step at all.
1] A Holistic Restoration:
Picture #2 – Cat vomit stains is classified as a protein stain, which has the tendency to coagulate with the leather protein fiber; thus making removal more difficult than any other stain because of its penetrating and coagulating capability within the leather structure.
a) A high pH cleaner is necessary to do the job using d’Protein-9.9 (pH 9.9) to wedge and swell the protein fiber before the stain can be release. Dwell time is also an important factor to allow the leather to become more flexible and flaccid. Water contents should be able to be squeeze out between finger and thumb to ensure proper soaking. At this stage the stain becomes fugitive again and it is towel extracted.
b) Degreasing can follow after much of the water content and soiling is extracted, in conjunction to remove the greasy component of the stain with Degreaser-2.2 (pH 2.2). This low pH besides degreasing controls dye bleeding and reduces fatliquor leaching out. It is used in conjunction to neutralize the high pH of 9.9; recharging the “amphoteric” leather protein fiber cationic (+ve). As all other leather constituents like fatliquor and dyestuff are anionic (-ve) “unlike poles attracts like magnets” to maintain the chemistry integrity of the leather.
c) Grease is removed noticeable of an emulsified creamy appearance; this creamy release is further rinse with an acidic Rinse-3.0 (pH 3.0) until the release shows clarity again.
d) Obviously the stain area cannot be contain as any solution applied to the stain area moves sideward’s; therefore the entire panel gets all soaked up.
e) To further move the foreign solid within the leather structure, Hydrator-3.3 is used to re-soak starting from the stain and feather out. Advance techniques use layers of thin absorbent tissue paper as an extension of the leather, free of air space. This technique allows the residual soiling to be caught instead of remaining on the leather surface as the moisture contends floats the soiling particulates through the tissue paper. The tissue paper is peel off the surface when crispy dry and any remnants soiling on the leather surface is erased using leather Eraser-4.
f) Inspection – Surface will appears cleaner and lighter with loss of luster if any of the stain deteriorated weaker topcoat is removed. This is restored after fatliquor replenishing.
g) Fatliquor replenishing follows with an appearance application and let natural dry. When almost dry Hydrator-3.3 is mist spray to check any residual surface deposit has to be wipe away.
h) Dry preparation is the final step where aniline gloss topcoat is applied to restore the luster.
Picture #1 – Degreasing follows the above procedure skipping the d’Protein-9.9 process.
Products you may need are found in this Kit A6.dr; dyes may not be needed in this case, otherwise the likely combination may comes from Yellow, Orange and a shade of either Red-Brown or Dark-Brown to match. d'Protein-9.9 is an add-on to this kit.
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Leather DoctorŽ Aniline Leather – Color Refinisher & Degreaser – Kit A6.dr
Use this leather problem solving guide for reference:
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Leather-Safe Aniline Leather Problem Solving Guide-A9
Roger Koh
[email protected]