View Full Version : Nubuck Chair Seat Urine, Loss of grain?

02-06-2014, 09:01 AM
Roger, we received a Nubuck chair with a dried Urine stain. We cleaned and rinsed the area and removed some color and the real problem is we removed some of the pebbled finish. Is there any way to restore the original pebble finish. I'm confident we can work on stain further and restore color if needed. But can the finish be restored?


I have a picture of the whole seat
A picture of untouched grain
and a picture showing half good grain and half of the distorted area.

Roger Koh
02-06-2014, 12:36 PM
>>> But can the finish be restored?

Unfortunate since nubuck is “unfinished” leather rather it is aniline smooth leather with a dye fix created nap. The pebbled grain loss is irreplaceable and remains as a natural scar. The only possibility is to feather out the edges of the scar to make it less outstanding.

Neglected urine damages may lead to dry rotting, which may be the case for the deterioration and damages.
The main culprit is the shifting of the urine to alkalinity that does the damaging and need timely rectification to neutralize and protonate it before it has gone over the pH chemistry integrity threshold.

Kit N5.uk performs Nubuck urine decontamination and color restoration is with Kit N7.cl combination.

Leather Doctor Kit N5.uk – Nubuck Urine Killer Kit
Leather DoctorŽ Kit N5.uk, nubuck leather urine killer kit is designed 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 with wet finger testing it. This stickiness is a sign of leather denaturing and reverting to rawhide. pH balance to stabilize the denaturing leather is rectify with Acidifier-2.0 prior to cleaning the protein residue with d’Protein-10. Rinse-3.0 may follow prior to treatment with d’Urine-2.1. 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 prior to fat and oil replenishing with leather scented Fatliquor LS-5.5. The surface wear of the leather is greatly reduced with a rub-resistant Protector-S+ that enhances a non-stick draggy-feel to shield against sticky soiling. Note that the mentioned products suffix numbers denotes its pH value in this holistic approach for nubuck leathers urine decontamination process.

Leather Doctor Kit N7.cl – Nubuck Dye Refinishing Kit

Leather DoctorŽ Kit N7.cl, nubuck dye refinishing kit is designed for dye refinishing after degreasing in a holistic approach. Most severely penetrated, prolonged and neglected stains from the bare head and hands that show a darkening effect with a sticky feel have its dyestuff probably deteriorated by the oil, grease and sweat. When the stain feels sticky, it is a sign of leather denaturing and reverting to rawhide from breaking of bonds with the tanning agent. When sign of dye is transfer to a white towel, it indicates that the dyestuff has also break bonds with the protein fiber. When leather is stiff or show signs of whitish residue migrating, it shows that the fatliquor is breaking bonds as well with the protein fiber. The main component of the leather protein fiber is amphoteric while the other constituents are not; shifting of the pH caused from sweat to alkalinity affects the pH imbalance. To revert from denaturing into rawhide prior to dye refinishing, contaminated alkaline soiling is removed with Degreaser-2.2, a waterbased (pH 2.2) multifunctional degreaser that emulsifies greasy contamination besides controlling dye bleeding and charging the protein fiber ionic positive for strengthening the attraction between the ionic negative tanning agent, dyestuff and fatliquor. Deflocculated and suspended soiling is towel extracted, thereafter rinse and pH balanced with Acidifier-2.0 to prevent the leather from reverting to rawhide. When leather feels sticky or slimy it is a sign of leather denaturing, a squeaky feel when wet is a sign of healthy leather. Hydrator-3.3 relaxes stiff leathers and removes surface tension free from surface blotchiness prior to fat and oil replenishing. Fat and oil is replenished with Fatliquor-5.0 to rejuvenate the leather for the desired suppleness when dry. Protector-S+ enhances a non-stick silky-feel to shield against sticky soiling. Note that the mentioned product suffix number denotes its pH value in this holistic leather-safe nubuck dye refinishing system.

Roger Koh
Leather Care Consultant