Aniline - Dog Urine Stain - How to salvage this 1940’s French Aniline Leather Sofa set from dog peed?

[Roger Koh]

Yesterday my old incontinent dog peed on my favorite antique leather sofa. As soon as I discovered in I washed it with dish soap & water and later covered it with a leather hydrator. It's not completely dry but I can see a much darker place where the urine was. Help! I've been searching online and you seem to be the most knowledgeable.

The stain occurred sometime in the night before Christmas. Christmas day when I discovered the accident I had little resources at hand. The hydrator is a product I bought in Germany that I have good success with conditioning leather in the past; it’s by PNZ called Antik Wachs. It is a rich wax type cream that conditions and is not at all tacky. I massaged the wax by hand into the entire sofa. Everything, but the stain looks lovely. Then we left town on holiday the 26th, only returning this afternoon. This is a 1940’s French sofa set that I am terribly fond of. It has a number of stains but they only give it character, this stain however goes beyond character and must be addressed. I am in hopes this package of products can ultimately make the stain less pronounced.

If you can help me repair this amazing antique piece, it would be a testimony to the value of your products. I will follow exactly what you prescribe and document every stage/step with photos. Thank you sincerely for your help and your interest.


#1


#2


#3 Here is the stain. The dark part is stiffer than the unaffected area


#4 Close-up


#5 Water beads up initially, but then soaks in when massaged.


#6 Water – 5 minutes after application.

[Roger Koh]

Visual Observation:

Picture #1 & #2
Except or other than the compounded urine stain in question, this sofa has its unique character in appearance and worthwhile to be conserved – with rejuvenating softness, suppleness and strength back to its chemistry integrity for practical usefulness.

Picture #3
Besides this sad look, “The dark part is stiffer than the unaffected area”. The leather has shrunk as can be seen from the cushion side lines. The lighter brown colors are typically of fresh urine stain that causes a leaching of leather constituents that includes the tanning agent, fatliquors and others. What causes the charring effect could be a compounding effect from the alkaline dish soap. Leather is acidic average pH from 3 – 5. Alkaline solution will normally browns it and acidic solution will lightens it. This leather may have eroded its natural acidity from past alkaline cleaning solution unknowingly, with alkaline overexposure resulting in visible dark mark at the lower central back rest. Leather protein fibers can either shift positive or negative depending on the acidity or alkalinity exposure during cleaning in relation to its isoelectric point. When an acid solution pH is below its isoelectric point, it will ionize the protein fiber cationic (+); if an alkaline solution is above its isoelectric point, it will ionize the protein fiber anionic (-). Urine when fresh is slightly acidic to neutral pH 7, when ammonia smell is detected it certainly is shifting alkaline towards pH 11. Almost all other leather constituents are anionic or negative, and when the leather protein fibers shift negative; it leaches out the leather constituents, behaving just like magnet “like poles repel”. Fatliquor, the lifeblood of leather is what the tannery put in place to soften up the leather for suppleness and strength. Fatliquor is derived from fat and oil in a water emulsion, ready to use looks just like fresh milk. The fat plumps the leather, the oil lubricates the individual leather fibrils like connecting hinges and the water evaporates leaving behind breathing pores in between the inter-fibrillary spaces. Now, the diminishing effect of fatliquor left these fibers become stick together, that’s how “the dark part is stiffer than the unaffected areas”.

Picture #4
This close-up picture reveals more cracks on the darker areas. The stiffer the leather the easier to crack it when flex; cracking is the breaking of the individual fibers just like bundles of fibers in a rope. And if left alone or compounding the problem may lead to tackiness when damp; the denaturing or reverting to rawhide. Eventually may lead to dry rot when a finger can easily put through sooner or later.

Picture #5
“Water beads up initially, but then soaks in when massaged”. The water testing is to determine the leather absorbency that the fibers are not sealed by the wax for access to flush out the foreign contamination. Besides the unsightly white creamy streaks, this untimely wax application put extra hurdles to the decontamination process and should be stripped off entirely. Massaging at this stage will cause further breakage of the protein fibers that will eventually join up as cracks. Leather can be soft and weak in this case from massaging stiff leathers. The logical approach is to relax the leather fibers with a hydrator to soften it without breaking its fibers, thereafter fatliquor replenish it to soften and strengthen it when dry.

Picture #6
This shows the mud cracking effect of the leather; the leather is basically “dry”. Dry of its essential anionic charged fat, oil and water contents. Prior to the urine damage and the innocent salvage attempt the fatliquor has been continuously evaporating as VOC (volatile organic compound) as seen from Picture #1 & #2 shrinking cushion on the left. The failed attempt in my opinion has caused more damages to the leather from leaching out the fatliquor than if left alone. The diminishing effects from evaporating and leaching has squeezed dry the life out of the leather; the lifeblood of leathers, fatliquor!

Question is, can the cushion be removed and is there a zip to access to the reverse side of the stain?

Then we can further discuss how best to save the situation.

Roger Koh
[email protected]

[Roger Koh]

These below pictures show that the stain has gone through the entire thickness of the leather.

The cushion is recommended to be plastic wrapped for a few reason:
1] Prevent it from staining.
2] Economize the usage of Hydrator-3.3.
3] To keep the leather in shape
4] Removal for inspection that the entire leather surface is equally hydrated out – would like to have pictures taken at this stage.
5] The reverse size should appear evenly without stains or marks when fully hydrated and when completely dry.

Note:
The only known leather-safe proven practice of removing contamination out of leather is by Hydrator-3.3.
1] The entire leather surface has to be evenly hydrated.
2] Since the stain has gone through the reverse – it has to be entirely hydrated and be seen evenly as so.
3] Towel Extraction is done from the surface until towel shows clean; with repeat reapplication and extraction until the contamination is effectively removed.
4] This hydrating is done with plastic wrapping to control evaporation while moving the contamination to the surface for towel extraction in a 72hrs session.
5] Result can be seen through the clear cling plastic wrap.
6] Besides using white terry towel for the extraction, horsehair detailing Brush-1, Eraser-4 and sandpaper 1000/1500grit is used in conjunction to improve the surface in the hydrating stage.

Needless to say, the topcoat has already been damaged and worth considering to be applied. Dyeing is for restoration, but for conservation; it may not be advisable for its "antique value" sake.

More will follow on the sequence of processes.

#1 Reverse Side 1


#2 Reverse Side 2


#3 Stain


#4 Stain Close-up

[lowsley]

I just received both packages from you, the decontamination kit and two additional bottles of hydrator. Please advise! Ready to get started.

[Roger Koh]

Get familiar with Kit-A3.uk...

Leather Doctor® Kit-A3.uk : Aniline Leather Urine Odor Killer Kit

Aniline leather urine odor killer Kit-A3.uk - features three specialty products; the d’Urine-2.1, d’Protein-10 and the Fatliquor LS-5.5 as the major contributors to the holistic leather-safe urine decontamination system. d’Urine-2.1 with a pH value of 2.1, is essential to neutralize the ammonia found in urine from shifting alkaline when it starts to decay. d’Protein-10 at pH 10 is to remove the coagulating protein component of the stain. Fatliquor LS-5.5 at pH 5.5 with its infused leather scent not only softens the leather structure when dry but also brings back the preferred classical leather scent over any other lingering odors. When urine stain has reached the tacky stage, topcoat refinishing is recommended with aniline Topcoat-79G found in Kit-A3.dr.
The care of urine decontamination, cleaning, and conditioning of all aniline leathers are the same; it’s their topcoat, fashion effect and matching tactile-feel protection that differentiate among them. Aniline leathers are dyed through with transparent dyestuff and most furniture leathers are finished with a clear topcoat that allows the natural beauty of the grain to show through with better durability. The beauty of the grains often comes with natural blemishes like scars as the complete original animal’s skin structure remain visible. Since transparent dyestuff is used for aesthetic appearance and to camouflage blemishes the intensity may varies accordingly. All aniline leathers uses the same transparent aniline dyestuff for coloring, pull-ups has additional wax or oil infused that makes the color comes alive; tactile-feel among them varies from buttery, draggy, waxy to silky. The standard aniline has the usual brighter luster Topcoat-79G with matching buttery-feel protection; while the waxed aniline has a waxy-feel matte appearance with Topcoat-59M and its matching waxy-feel protection; and pure aniline has its natural almost naked Topcoat-89N with its complimentary silk-feel protection. Another class of aniline is the pull-up and they are mostly wax than oil infused with Wax Effect-8.6 and Oil Effect-2.8 respectively into their leather structure. Complimentary tactile-feel surface protection is the matching draggy-feel for the wax pull-up and the buttery-feel for the oil pull-up. The name suffix of these products denotes their pH value. Leather has a pH value between 3 and 5, any leather cleaning products that has this similar pH range should be deemed leather-safe; otherwise has to be pH balanced thereafter to return to its pH chemistry integrity. Unlike non-absorbent leathers, generally almost all liquid will penetrate into the aniline leather structure, thus leather-safe products strengthens, while non-leather-safe products denatures the leather. These products are designed to provide safe and effective care of leather appearance through urine decontamination, cleaning, and protection. Including the essential leather rejuvenating system of hydrating stiff leathers and replenishing original fatliquor to prevent dryness by restoring its softness, suppleness and strength.

■ Aniline Leather - Urine Decontamination System:
The damaging effect of urine - when fresh it is mildly acidic to neutral with hardly any smell. It is the uric contents that attract the natural bacteria from the atmosphere and when fermented shift its pH value alkaline; from distinctly ammonic smell to the foul mercaptan smell at the advanced stage. The intensity of the odor will depends on the amount of urine deposited, frequency and urine types; with pets urine seems to produce the strongest odor. Severe and advance stage stain may produce fugitives black and white residues; the blacks may derive from the tanning agent and the white from the fatliquor. When the urine turns alkaline, it will shift the protein leather fibers negative below its isoelectric point; that repels the ionic negative tanning agent and fatliquor like magnet does ‘like poles repel’, thus the breaking of the hydrogen-bonding between them. This phenomenal of breaking bonds is the beginning of the denaturing of the leather resulting from tackiness to eventual dry rotting.
Instructions
1st phase - Dry Soil Removal:
1] Disposable latex gloves and dust mask protection during dry soil removal is recommended depending on the severity of the urine contamination.
2] Dry soil removal may involve - erasing with the sponge side of the leather Eraser-4 and stitching seams brushing with horsehair leather Brush-1. 3] It’s recommended to test wipes the entire surface with a white absorbent towel to check for effective dry soil removing until towel shows clean, prior to moving into the wet cleaning phase.
2nd phase - Wet Soil Removal:
Note: It is recommended to wear latex gloves and mist mask as personal protection. The sour odor is a sign of the continuous working power of the d’Urine-2.1 and will eventually wears out.
2a) Fresh Stain:
1] Spray d’Protein-10 to saturate the stain, horsehair Brush-1 agitate and towel extract until it shows clean.
2] Spray d’Urine-2.1 to saturate the stain, horsehair Brush-1 agitate and towel extract until it shows clean.
3] Spray Rinse-3.0 to saturate the stain and towel extract until it shows clean.
2b) Tacky Stain:
1] Apply d’Urine-2.1 to saturate the stain, horsehair Brush-1 agitation to penetrate and towel extract until it shows clean to a squeaky feel.
2] For severe cases spray to saturate the stain and cling wrapped to dwell 8 hours or overnight follows with towel extraction until it shows clean.
3] Apply d’Protein-10 to saturate the stain and horsehair Brush-1 agitate follows with towel extract until it shows clean.
4] Reapply d’Urine-2.1 to saturate the stain again, brush agitate and towel extract to neutralize the high alkalinity of the d’Protein-10.
5] Spray Rinse-3.0 to saturate the stain and towel extract until it shows clean.
3rd Phase Hydrating:
Leather structure hydrating is to facilitate the dispersion of the remaining foreign contamination still suspended, to wicks up, for a periodic towel extraction while damp and eliminating rings when dry.
3rd phase - Structural Leather Scent Enhancing with Fatliquor LS-5.5:
This phase is to infuse the leather structure with this leather scent fatliquor as a 2-in-1 treatment with hydrating as the preconditioner. The scentless version is available as Fatliquor-5.0.
3a) Hydrating:
Hydrating process in this urine decontamination system is to facilitate an effective internal water movement in the inter-fibrillary spaces; to suspense and wick foreign contamination to the surface to be towel extracted repeatedly while damp and erased when crispy dry. Additional technique is to cover the surface with absorbent tissue paper to trap foreign residue as it wicks through in the final drying process. Thus it is essential that moisture level reach an optimum level with moisture oozing out when press between finger and thumb. It would also require more dwelling time for the hydrator to do its work effectively. This is done with plastic cling wrapper to control evaporation for an overnight dwell. The benefit of a longer dwell reduces contrast from stain removing as the dormant dyestuff is activated to surface. It also allows charging of the protein fibers below its iso-electric point positive, to effectively hydrogen-bond with the ionic negative charged fatliquor.
1] Spray Hydrator-3.3, spread with foam brush to plump the entire thickness of the leather.
2] Advance technique uses absorbent tissue paper to lay over the entire surface, soak and free of air spaces as an extension of the surface.
3] This technique allows wicks up foreign soiling to be caught through by the tissue paper when it’s perfectly dry.
4] The crispy dried surface is further dry clean with Brush-1 and/or Eraser-4 to remove wicks up soiling particulates for inspection.
5] Repeat as necessary or proceed to fatliquoring.
3b) Leather Scented Fatliquor Replenishing:
Leather scent enhancing in urine odor removal is the natural choice over any other lingering odors. This infusing the thickness of the leather with the classic leather scent will have a longer lasting effect than just merely from the surface that is subject to rubbing off. Fermented urine alkaline overexposure may have cause fatliquor to leach out that timely replenishing is highly recommended. Besides the primary function of maintaining the leather for suppleness; it also contributes to the overall appearance in boosting the overall color intensity. Without fatliquor replenishing it will turn stiffer when dry and when flex or pressure is put on them will eventually crack. It is recommended to inspect the surface for an even appearance with Hydrator-3.3 prior to fatliquor replenishing it. Effective fatliquor is to saturate the leather structure, plumping it, in between water content evaporation. When dry thereafter, the leather fibrils will be well separated and lubricated to slide over one another smoothly during practical usage with softness, suppleness and strength.
1] Spray Fatliquor LS-5.5, spread with foam brush plumping it for an even appearance.
2] Repeat application in between water contents evaporates until it’s saturated.
3] Leave to natural dry for extra softness.
4th phase – Leather Scent Protection:
This protection has its contributing benefits: non-stick against sticky soiling making cleaning easier; rub-resistant reduces wear to the topcoat, thus prolonging its natural luster appearance; imparting the unforgettable classic leather scent that charms. Otherwise the scentless version is available as Protection-B.
1] Apply Protection-B+ after shaking well, spread with lint free towel and is ready for use when dry.
Color Refinishing Option:
Topcoat inspection is done at this stage to determine the extent of existing damages. As salvage cleaning may further remove deteriorated and weak finishes, topcoat refinishing is recommended. If original topcoat has been abraded off, it’s often noticeable with a duller appearance. Aniline Dye-21 and Topcoat-79G color refinishing system to match is an option.
5th phase - Non-stick Rub-resistant Protection:
This protection has its contributing benefits: non-stick against sticky soiling making cleaning easier; rub-resistant reduces wear to the topcoat, thus prolonging its glossy appearance; imparting the unforgettable classic leather scent that charms. Otherwise the scentless version is available as Protection-B.
1] Apply Protection-B+ after shaking well, spread with lint free towel and is ready for use when dry.

Featured Contents:

Leather Doctor® d’Protein-10 in 250ml
This is a pH 10 aqueous leather protein stain remover. It’s for removing blood, body-discharge, milk, cream, ice-cream, egg, meat juices, vomit, perspiration, urine and other protein based stains. And any staining that comes from a living animal or person will probably need this product in the removing process. Use as accordingly to other leather trim including; aniline, vachetta, nubuck, suede, hair-on-hide and woolskin.

Leather Doctor® d’Urine-2.1 in 250ml
This is a pH 2.1 aqueous leather urine stain neutralizer. It’s for neutralizing the ammonia and alkaline phosphorus salt found in urine from “reverse-tanning” the leather.
It’s applicable and use accordingly to other leather trims that may include; aniline, vachetta, nubuck and suede.

Leather Doctor® Fatliquor LS-5.5 in 250ml
This is a pH 5.5 leather scent fortified fatliquor to impart an unforgettable classic leather scent into the leather structure as the main objective for its usage. More than what Fatliquor-5.0 is used for, primary to rejuvenate the leather structure for softness, suppleness and strength. To replenishes original fatliquor that diminishes thru ageing, heat and alkaline exposure or cleaning. To penetrates and lubricates the leather fibers so that after drying they will be capable of sliding over one another smoothly. Besides to softens the leather with stretchability, compressibility and flexibility; fatliquor enhances its rip tensile strength greatly. Relaxes coarse breaks, creases and wrinkles to provide tautness, suppleness and prevents cracking. To help to keep leather at its optimum physical performance and prevent premature ageing. It’s safe for all other leather trims including; aniline, vachetta, nubuck, suede, hair-on-hide and woolskin.

Contents:

Leather Doctor® Prep-4.4 in 60ml
This is the leather-safe milder version of Prep-7.7 with a Ph value of 4.4. It’s high viscosity; designed to be painted on neatly; with a foam brush onto the leather. It works by allowing sufficient dwell-time; to penetrate, lubricate and suspense foreign soil contamination; prior to extraction with towel. It’s is used to strip foreign soil contamination prior to refinishing. Also as stains remover for: Grease based ink stains like ballpoint ink.
Water based ink stains like stamp pad ink. Dye transfer stains like blue jeans, ink prints and newsprints.

Leather Doctor® Cleaner-3.8 in 250ml.
This is a Ph 3.8 all purpose leather-safe anionic cleaner that is particularly effective in emulsifying oily soils and in suspending its particulates. It works by penetrating, lubricating and suspending soiling safely and effectively through gentle chemical reaction; working in perfect harmony with all leather constituents that include the tanning agent, preservative, dyestuff and especially the fatliquor. It’s safe for all leather trims including; aniline, vachetta, nubuck and suede. This product is always followed through with Rinse-3.0 as a system to a healthy squeaky feel.

Leather Doctor® Rinse-3.0 in 250ml.
This is a pH 3.0 aqueous anionic leather-safe rinse to neutralize harmful alkaline and perspiration residues; for stabilizing and strengthening leather to its neutral pH value of 3 to 5 chemistry integrity. It’s safe for all leather trims including; aniline, vachetta, nubuck and suede.

Leather Doctor® Hydrator-3.3 in 250ml
This is a pH 3.3 aqueous leather-safe hydrator with active surfactantcy for lowering the interfacial tension between the protein leather fibers and its constituents. It’s for relaxing creases and wrinkle and eliminating them while damp prior to fatliquoring it. It’s for hydrating dried, stiffed or shrunk leathers to separates the crushed, stick together fibrils and relaxes them in the inter-fibrillary leather structure for effective distribution of the Fatliquor-5.0. It’s for charging the leather protein fibers below its iso-electric point positive to hydrogen-bond with the ionic negative charged Fatliquor-5.0. It’s for facilitating colloidal water movement within the leather structure during the wicking process to move soiling particulates to the surface. It’s for reactivating the dormant dyestuff to resurface thus reducing the contrast between the color coat and the leather crust. It’s for reducing or eliminate blotchiness when dry especially absorbent leathers. It’s for facilitating better finish penetration during refinishing thus providing good surface properties, especially the uniformity of surface dyeing during aniline refinishing. It’s safe for other leather trims that may include aniline, vachetta, nubuck, suede, hair-on-hide and woolskin.

Leather Doctor® Fatliquor-5.0 in 250ml
This is a pH 5.0 anionic charged micro emulsion fatliquor leather rejuvenator. It’s for replenishing original fatliquor that has diminished thru sun-bleaching, ageing, heat and alkaline exposure or cleaning. It penetrates and lubricates the leather fibers so that after drying, they are capable of sliding over one another smoothly. Besides softening the leather with stretchability, compressibility and flexibility; fatliquor enhances its rip tensile strength greatly thus reduces split or tear to the stitching and perforated holes. It relaxes coarse breaks, creases and wrinkles to provide drapes, suppleness and prevents cracking. It helps to keep leather at its optimum physical performance and prevent premature ageing. It’s safe for all other leather trims including; aniline, vachetta, nubuck, suede, hair-on-hide and woolskin. It is available with infused leather scent as Fatliquor LS-5.5.

Leather Doctor® Protection-B+ (Leather Scent-B) in 120ml.
This is a non-film forming, non-stick rub resistant protector that enhances a soft natural buttery-feel with an unforgettable classic leather scent. It’s for imparting a non-stick breathable barrier essentially to shield the detrimental effects of sticky soiling including the nasty ballpoint ink. It is effective to release those tenacious dye-transfers stains especially on light colored leathers easily, without resorting to unnecessary color refinishing. Its natural buttery-feel protection increases the leather resistance to wet and dry rubs, thus reduces stretch, scuff and abrasion. And it reduces friction squeaks that wear the finishes when leather is rubbed against during used.

Horsehair Detailing Leather Brush-1
This horsehair detailing brush is ergonomically designed to be an extension of our hand with sturdy grooved grip, designed to produce an effective result easily and efficiently for many years to come. It’s recommended for all smooth leather, to deliver a scratch-free agitation cleaning. The length is 7 inches with a three row 1½ inches bristles cleaning head.

PolyBrush®
This is the 3” made in USA washable foam brush that last. It’s used for spreading the Prep-7.7, rinse clean and thereafter used for the leather Scent-B and Scent-D application to prevent overspray.

Washable Rags
This rag works like cloth, lint free and highly absorbent for extracting suspended soiling or for wiping the leather Scent-B and Scent-D during routine easy cleaning-protection application.

Refills are available…for more information email [email protected]

[Roger Koh]

and get ready the cushion with tools mentioned earlier...

1] Cushion plastic wrapped and inserted back in place.
2] Besides using white terry towel for the extraction, horsehair detailing Brush-1, Eraser-4 and sandpaper 1000/1500grit is to be used in conjunction to improve the surface in the hydrating stage.