Urine on full aniline leather sofa?

My elderly cat peed on my leather sofa. I soaked up what I could but unfortunately she did it overnight so it had mostly dissipated by the time I realized what had happened. I see there are a couple similar threads with animal urine on leather but the guidance seems to vary a bit by situation so just want to make sure I understand the best approach to getting the stain out (if possible).

The attached photos are what the couch looks like in a mostly/nearly dried state as well as the underside. It’s definitely a bit stiffer than the rest and when wet, the underside does have that tacky slimy feel I’ve learned here is an indicator the leather is breaking down and returning to rawhide. I can’t remove the leather cover off the cushion fully, as it’s sewn to the cushion in places but I can reach most of the undersides. Any thoughts on the best way to tackle?

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>>> Any thoughts on the best way to tackle?

The ideal approach is from the suede side, both in terms of easy absorbent, and working from the suede side will reduce further stress to the aniline finishes.

For your reading

Urine:
Urine is a compound waste discharge, comprises of urochrome, uric acid, and the ammonium salt to deal with. When deposited urine attracts the natural bacteria from the atmosphere and starts to ferments, a putrid odor will develop from the protein component of the urine and ammonia odor will develop from the ammonium salt. When ammonic odor becomes present, the pH of the contamination would have shifted to 10. Such high pH above the neutral average 3 to 5 of leather causes the amphoteric protein fiber to shift ionic negative (-ve); that causes the protein fibers to repels its other ionic negative (-ve) constituents like the tanning agent, fatliquor and dyestuff. Behaving just like the attraction of a magnet, alike poles repel. When the leather constituent breaks hydrogen bond with the protein fiber, the leather starts to denature and revert to rawhide. A typical appearance of an aged or compounded contamination is a darkening effect from the fugitive tanning agents, a whitening effect from the fatliquor. Fugitive dyestuff or bleeding is only apparent from a white towel detection and yellowing from the urochrome. The denaturing or reverting to the rawhide effect of the leather is further confirmed by tackiness or in worst-case sliminess in the present of moisture. The leach out fatliquor results in stiffness and fugitive dyestuff results in discoloration. A systematic sequence of decontamination approach includes surface residue removal with CleanUrine-1.5 (pH 1.5), and rinse with Acidifier-2.0 (pH 2.0) recharging the protein fiber ionic positive (+ve) and neutralizing the ammonium salt with KillUrine-2.1 (pH 2.1). Utilizing such a low pH treatment retards bacteria activities from off-gassing putrid odors, a natural pH control without the need to use bactericide or fungicide for mold prevention. Therefore, urine is a type of soiling that will require a biochemistry approach to decontaminate it. Restoring the leather begins after decontamination with Hydrator-3.3, a pH 3.3 multifunctional product that has ionic positive (+ve) charging abilities, active surfactants essential for foreign water movement within the inter-fibrillary spaces to redistribute the leather constituents and purging foreign contamination to resurface. This is the last of the wet cleaning process to remove the suspended urochrome yellowish compound through visible white tissue paper as an extension of the leather in the wicking process as the leather dries naturally. Only then, without a trace of the urine stain that Fatliquor-5.0 (pH 5.0) replenishing commences. The emulsified fat and oil encased water molecule breaks free when hydrogen bond attraction takes place between the fat and oil with the protein fiber, leaving a breathing space essential for leather transpiration to function naturally. The fat plumps the leather with fullness from easily collapsing into creases and wrinkles during stress or flex, while the oil lubricates the fibers so that they slide over one another like millions of inter-connecting hinges with smoothness. One important unique characteristic of leather is suppleness with strength and much depends on the fatliquor, in this holistic approach to effective leather urine decontamination and restoration. For severe neglected cases with finishes damages as seen in this picture, refinishing commences after leather suppleness restoration.


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https://www.leatherdoctor.com/leathe...tor-kit-l5-uk/

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Roger Koh
Leather, Skin, Hair, Eye & Acne Care System Formulator
Consultant / Practitioner / Instructor / Coach
web: www.leatherdoctor.com
forum: www.leathercleaningrestorationforum.com
email: [email protected]

Thank you, Roger! So I did a round of the CleanUrine, Acidifier, and KillUrine and there definitely seems to be improvement with the staining as well as a reduction in the slimy texture when wet and less color transfer when blotting with a clean towel. However, there is still some staining and wondering if it is worth repeating the decontamination steps before moving on to the restoring steps or if this is to be expected? I realize, of course, that some remaining staining may be unavoidable given the severity of the case.

>>> there is still some staining and wondering if it is worth repeating the decontamination steps
Yes, you could repeat the decontamination steps. Good also if you show some pictures.


>>> that some remaining staining may be unavoidable given the severity of the case.

The remaining staining could possibly be improved with surface treatment using LeatherTarnishRemover-1.3 > LeatherBasifier-8.8 system as an option.