From pictures this leather is identify as “Aniline” with a gloss luster.
We shall discuss your 2 main problems; the smell and the darkening effect; and how to solve it as the first phase prior to determining if it would require further dye and topcoat refinishing.
Urine Smell/Odor:
Urine when fresh is often odorless, it’s the protein content in the urine that attracts the natural bacteria from the atmosphere and when fermented off gassing that result in smelling. When ammonia smell is detected the pH value may have already reach 10; While the neutral of leather averages 4. Thus at every increase of one pH point the strength has increase 10 times. So from pH 4 to 10; the leather is one million times alkaline over exposure. The pH phenomena may also be compounded with using Baking Soda which has a pH of 8 – 9 depending on concentration.
at pH 5 = 10 times
at pH 6 = 10 x 10 = 100 times
at pH 7 = 100 x 10 = 1000 times
at pH 8 = 1000 x 10 = 10,000 times
at pH 9 = 10,000 x 10 = 100,000 times
at pH 10 = 100,000 x 10 = 1,000,000 times.
The Darkening Effect:
This darkening effect could be the coloring from the tanning agent and/or dyestuff that has leached out from such high pH exposure. Alkalinity on leather browns the leather and on severe cases charred it; while acid lightens it. Leather is protein fiber and it is “amphoteric”; acidity or alkalinity such as urine and baking soda will shift it ionic charges negative (-ve). Thus causing the protein fiber breaking it’s hydrogen bond with its other leather constituents like the tanning agents, dyestuff and fatliquor which remains unchanged ionic negative (-ve); behaving just like a simple magnet – like poles repel – without effective decontamination the leather begins to denature and other side effect is tackiness or sliminess that leads to stiffness and dry rot.
The recommended sequence of procedure is as follows:
1] Test for tackiness or sliminess using tap water and detect with fingers; if it is tacky or slimy spray d’Urine-2.1 and soak the stain area, blot with towel; until a squeaky feel is detected; if the feel is normal using tap water as the surrounding areas with squeakiness, the leather is healthy enough to proceed with d’Protein-10.
Note: since the leather is already removed from the cushion; it is safer to do all the harsh agitation from the suede side, avoiding further physical rubbing which may have already removed the topcoat (Aniline Topcoat-79G), besides the dye leaching out.
2] Remove the Protein Component (uric acid) of the Stain:
Use d’Protein-10 – Spray onto the stain and let it soak thru and dwell for up to 30 minutes with periodic blotting the contamination until the white towel shows clear.
3] Neutralize the pH 10 of the d’Protein-10 and the Ammonia salt of the Urine:
Use d’Urine-2.1 – Spray onto the stain and let it soak thru, blot with towel through the thickness, preferably from the suede side until the towel shows clean; then spray soak though the stain and let it natural dry. The lingering sour odor will dissipate when its work is completed.
4] Hydrate to Redistribute the Displace Leather Constituents to re-Stabilize the Leather Chemistry Integrity:
Use Hydrator-3.3 and soak through (by spraying and foam brushing) the entire thickness of the leather that need to cover the entire cushion (I do not think that the 250ml can do a sufficient work to cover the ENTIRE surface area through the thickness, for such a large cushion – “these large cushion pictures came late to advice you accordingly”); You would need at least 4 times the amount to do this project effectively. This soaking is best to dwell for up to 72hours; while keeping the moisture level oozing wet when press between finger and thumb. During the dwelling time the entire cushion is recommended to be put into a see thru plastic bag or loosely cling wrapped it. This is done with having the cushion plastic wrapped from getting wet. That is to say that the leather is between the two layers of plastic, while the cushion is in place. During the dwell; the stain area is periodically blot so that the internal moisture from the surrounding areas are pull through to suspend the foreign contamination to the surface. Attention is pay to the evening out of appearance of the stain, even while soak wet; before removing the exterior plastic wrapping. The stain areas are further treated with facial tissue by wet cling wrapping it without air spaces. This allows any residual stains to be caught while wicking through the tissue paper, instead of remaining on the surface. This drying process is left to dry naturally.
5] Inspection:
When crispy dry, peel off the now stick together tissue paper. Wick up residue that remains on the leather surface if any is erased with leather Eraser-4. Any topcoat damages may reveal as dulling or lightening of color; that may require refinishing with Aniline Topcoat-79G, after fatliquor replenishing it.
6] Fatliquor Replenishing:
Use Fatliquor-5.0 spray and foam brush to saturate the leather for an even appearance, finish the entire bottle, letting it soak in, water contend evaporates before the next application.
Note:
Show pictures of every step above; and the step 6 will determine whether it’s necessary to topcoat refinish it with Aniline Topcoat-79G to even out its pre-damaged luster.
Roger Koh
[email protected]
Here’s the urine decontamination kit, you may need refills and topcoat system to refinish it; dyeing is the last resort but unlikely necessary.
http://i300.photobucket.com/albums/nn4/Rogerkoh/Leather%20Doctor%20products/KitA3uo.jpg
Leather Doctor® Aniline Leather – Ammonia pH Neutralizer – Odor Killer – Urine – Kit A3.uo