View Full Version : Urine stain on Italian Nubuck leather sofa!

01-04-2017, 03:43 PM
Urine stain from my granddaughter.
Sofa color didn't come through very well.
It is a medium to light green.



Roger Koh
01-04-2017, 03:53 PM
Follow this holistic system to complete remove, decontaminate, rejuvenate and protect. The stains should vanish at the end of the system. Let me know and show some pictures if you are stuck without getting the desired expected result. You may post any questions before you commence to be doubly sure of what you will be doing. Below is the recommended kit.

Leather DoctorŽ Kit-N5.uk nubuck urine killer kit is specially formulated to decontaminate urine problems. Aged urine is detectable with its characteristic ammonic odor. The presence of ammonic odor may indicate the shifting of pH value up to 10. The leather will most likely feel sticky or slimy when wet finger testing it. This sticky feeling is a sign of leather denaturing and reverting to rawhide. Stabilizing this sticky phenomenon is done with pre cleaning with CleanUrine-1.5 follows with Acidifier-2.0. KillUrine-1.2 treatment is to neutralize the urine turning ammonic and is let to soak in contact for chemical reaction to take place and is very noticeable with a strong sour odor. This odor diminishes as it slowly evaporates. At this stage, the leather should feel squeaky after returning to its chemistry integrity of pH 3 - 5. Stiff leather is relaxed and sticks together fiber separated by Hydrator-3.3. The penetrated stain removing process continues with hydrating until complete satisfaction during a dry inspection prior to fat and oil replenishing with leather scented Fatliquor LS-5.5. In severe cases color refinishing is the last resort for a pleasing appearance. Note that the mentioned products suffix numbers denotes its pH value in this holistic approach for perforated-leather urine decontamination process.

Tips on 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 ammonic 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, like 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 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, an active surfactantcy 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 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.


Restoration Cleaning: 1. Dry surface soiling is removed with NubuckBrush-2 and Eraser-4 vacuum off. Remaining soiling is removed with CleanUrine-1.5 (pH 1.5) in conjunction with detailing NubuckBrush-2, Eraser-4 and terry towel extraction until towel shows clean. The remaining residue is further rinse off with Acidifier-2.0 (pH 2.0) and towel extraction until towel shows clean. Leather surface is inspected for any tackiness and should return to a healthier squeaky feel after rinsing.

Urine Treatment: 1. Apply KillUrine-2.1 and let it soak until natural dry. Sour odor will dissipate once it evaporates completely.

Hydrating: 1- Hydrator-3.3 is applied to soak into the leather to relax stiff and stick together fibers and to wick out suspended foreign contamination. 2- Wrapping the leather with paper towel and wet it out with Hydrator-3.3 is an advance technique to let the leather soak up the hydrator for slow absorbent leathers. 3- The paper towel is left on the leather to dry naturally; this technique allows the wick soiling particulates to be trapped by the paper towel instead of remaining on the leather surface.

Fatliquoring: 1- Fatliquor.LS-5.5 is applied and distributed with brushing until the leather is saturated. 2- Continuous second or third application is repeated with each round and let the water content evaporates until saturation. 3- Leave the leather natural drying for extra softness.

Rub-Resistant Protection: 1- Protector-S+ is applied by mist spray and brushing to even out appearance. 2- For routine application, a paper towel is recommended to extract soiling simultaneously.

02-07-2017, 10:19 PM
Appearance is somewhat better, but still darker than other cushion.
Will try eraser now.


02-07-2017, 10:20 PM
Somewhat better.
Will try Eraser-4 next.


02-07-2017, 10:22 PM
Better, but still darker.
Suggestions or should I let well-enough alone and apply protector?
Should I apply protector to the whole couch?


Roger Koh
02-07-2017, 10:24 PM
I think we are no more looking at soiling.

It is more of a color saturation and if you clean the adjacent cushion as well using the same product system the appearance will match up.

Want to give it a try?