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View Full Version : Nubuck leather by GAMMA (Italy) – stains collection from recent to 7 years old



koa
03-15-2014, 10:38 PM
The large geographic stain on the seat is from one of my kids who slept on it and had an accident (peed) on it. The other stains on the seat are from water/liquid - eating in the area.

The dripping stains on the back and arm rests - We have a special need child that we thought was dripping pancake syrup on it when we saw the first couple of them. Over the years we found out that he goes downstairs at night, get naked and hump the chairs.

The stain are from recent to 7 years old

Obviously I like the wrong type of finish for my family situation.

My intentions are to try and get the stains off, change the color to disguise them (if necessary), and protect the surface better. I would also consider converting the finish.

Thank you very much.
KOA

#1
2678

#2 - back of sofa, dripping stain from special need child humping chair
2679

#3 - Tried to clean b4 doing my research
2680

#4 - kid pee (large stain) body oil, food and drink stains on sofa seat
2681

#5 - body oil, food and drink stains on seat
2682

Roger Koh
03-17-2014, 09:48 AM
Pictures shows this nubuck comes with leather trim of aniline type.

The below problem solving guides will therefore be used accordingly.

1 Nubuck (N) Leather Problem Solving Guide

2722


Nubuck is top-grain cattle leather that has been sanded or buffed on the grain side, or outside, to create a velvet like texture or nap. It has the characteristic of a slight nap, with the softest “hand” or tactile feel. Although nubuck is aniline dyed through and sanded it is commonly finish with a surface dye sometimes incorporating micro-pigment to cover up some natural blemishes. It looks similar to suede, but the difference is that suede is created from the flesh side of leather, whereas nubuck is created from the grain side of leather. As both nubuck and suede are napped leather, it is often incorrectly identified as suede. Leather is both hydrophilic and oleophilic, nubuck especially with its open nap absorbs both water and oil more readily, than any other smooth leather. It is generally more expensive than suede; fashion types include embossed, oil and wax pull-up effect. Fatliquor plays an important role when comes to maintenance to both reduce ingress of waterbased and grease stain; plumps the leather with fullness, reduces creases, and wrinkles. Leather protein-fiber component is amphoteric therefore, a leather-safe (pH 3 - 5) care product system is highly recommended to keep them clean while maintaining their chemistry integrity.




2 Aniline (A) Leather Problem Solving Guide

2689

Roger Koh
03-17-2014, 04:19 PM
>>> The large geographic stain on the seat is from one of my kids who slept on it and had an accident (peed) on it.

It would be good to have a more detailed close-up pictures for a closer inspection and how old is the stain?

Recommended kit for the urine stain is this Kit N5.uk for Nubuck.

2692
Leather Doctor Kit N5.uk – Nubuck Urine Killer Kit
Leather Doctor® 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.

Roger Koh
03-17-2014, 04:27 PM
>>> The other stains on the seat are from water/liquid - eating in the area.

Most liquid from drinks would contain tannin, the coloring derive from plants and vegetation and would require a specialty tannin stain remover such as d’Tannin-3.5 from this Kit N5.ns as an add-on to the main Kit N5.uk.

2693

Leather Doctor Kit N5.ns – Nubuck Tannin Remover Kit
Leather Doctor® Kit N5.ns, nubuck leather tannin stain removal kit is designed to remove cellulose stains such as coffee, tea, wine and other stains that derive from plants and vegetations will probably be removed with d’Tannin-3.5. It is a waterbased leather-safe tannin stain remover. Surface residue is removed with Cleaner-3.8 follows by Rinse-3.0 and let dry prior to d’Tannin-3.5 treatment. As most stains become penetrated, an inter-fibrillary colloidal water movement is further facilitated with Hydrator-3.3 to move suspended stains to resurface prior to fat and oil replenishing. Fatliquor-5.0 imparts leather with softness and strength when dry. The surface wear of the leather is greatly reduced with a rub-resistant Protector-S+ that enhances a non-stick silky-feel to shield against sticky soiling. Note that the mentioned products suffix numbers denotes its pH value in this holistic approach to removing vegetables and plants derived stains from nubuck leathers.

Roger Koh
03-17-2014, 04:38 PM
>>> The dripping stains on the back and arm rest - We have a special need child that we thought was dripping pancake syrup on it when we saw the first couple of them. Over the years we found out that he goes downstairs at night, get naked and hump the chairs.

All protein related stains has a tendency to coagulates and stiffen the nap will require removing them with d’Protein-10 > Acidifier-2.0 system. A coarser suede eraser than the leather eraser helps with better traction to remove excess deposit. Refills for these two products are available from the on-line store.


2694

Leather DoctorKit N5.ps – Nubuck Protein Remover Kit
Leather Doctor® Kit N5.ps, nubuck leather protein stain removal kit is designed to remove protein based stains that tends to coagulates. d’Protein-10 is designed to deflocculates coagulating protein stains such as blood, body-discharge, milk, cream, ice cream, egg, meat juices, vomit, perspiration, urine and other protein based stains. Moreover, any staining that comes from a living animal or person will probably need this product in the removing process. Acidifier-2.0 is a leather pH stabilizer that is used to rinse and neutralize to its desired neutral pH of 3 - 5 simultaneously and ensures that the leather retain its healthy squeaky feel with a wet finger testing. Hydrator-3.3 relaxes stiff leather and reduces surface tension prior to fat and oil replenishing. Fatliquor-5.0 replenishing rejuvenates the leather structure for softness and suppleness when dry. The surface wear of the leather is greatly reduced with a rub-resistant Protector-S+ that enhances a non-stick silky-feel to shield against sticky soiling. Note that the mentioned products suffix numbers denotes its pH value in this holistic approach to removing protein based stains from nubuck leathers.


2695
Suede Eraser-5
This is a 2½ x 2 x ¾ inch fine pumice block with corrugated side for effective nap exfoliation

Roger Koh
03-17-2014, 04:56 PM
>>> My intentions are to try and get the stains off, change the color to disguise them (if necessary), and protect the surface better. I would also consider converting the finish.

Stains are considered foreign contamination and have to be removed as much as possible, leather rejuvenated prior to color to disguise or camouflage them. Protection is comes in three levels, the saturating of the leather structure with fatliquor impedes ingress of liquid stain to a degree. Dyestuff is protected with a dye fix from crocking or bleeding and a non-stick rub-resistant protector keeps the surface for easy cleaning. Converting the finishes would be an option, in my opinion I would rather retain as nubuck for more seating comfort with class. To camouflage any remnants stains the darkest present would be the lightest choice of color to hide them and the leather should return to its “finger writing effect” with softness and strength.

Degreaser-2.2, Nubuck-28 and Dyefix-99 would be addition for a camouflaging color refinishing to the Kit N5.uk.

2707
Leather Doctor Kit N7.cl – Nubuck Dye Refinishing Kit
Leather Doctor® 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 shows 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.

koa
03-18-2014, 08:29 PM
The urine stain has been on for about 4 years; the dripping stains <1 to 7 years; the food and drink stains <1 to 5 years. To think about it, I also applied protection cream about 4 years ago (with minimal knowledge of types of leather).

#1 - dripping stain
2712

#2
2713

#3
2714

#4 - Food and drink stain
2715

#5 - Urine stain
2716

Roger Koh
04-07-2014, 09:36 AM
http://www.leathercleaningrestorationforum.com/forum/showthread.php?8144-How-to-salvage-this-1940%92s-French-Aniline-Leather-Sofa-set-from-dog-peed

The system approach for dried urine stains are the same, however have to take note that the leather type and finishes may differ so tools used have to match the finishes. Use the Nubuck (N) Leather Problem Solving Guide posted above as reference. Urine under the heading of “Stain Type” is solved by the system step 1 to 7 from left to right. Steps 1 to 5 is the cleaning phase and remains until the result proves satisfactory before moving into leather rejuvenating it as the second phase with step 5 and 6. When dry it is finished with step 7.

Now we start with the cleaning Post #7 picture #5 as follows:

#1. Dry soil removal utilizes tools Eraser-4, Eraser-5 nubuck Brush-2 and a vacuum cleaner to remove surface soiling.
#2. The stain area nap may have been chemically deteriorated or damaged from the urea content that shift the leather protein fiber ionic negative (-ve) or alkaline. Using Eraser-4 first and follows with Eraser-5 to completely removed surface damages that may lighten up the stain area to match the surrounding. This removal is feather out to the entire cushion surface to the edges. Follows with a thorough vacuuming completes the dry soil removal process.

Let have some pictures for inspection before the next step.


Roger Koh
Leather Care Consultant
www.LeatherDoctor.com

koa
04-08-2014, 05:39 AM
http://www.leathercleaningrestorationforum.com/forum/showthread.php?8144-How-to-salvage-this-1940%92s-French-Aniline-Leather-Sofa-set-from-dog-peed

The system approach for dried urine stains are the same, however have to take note that the leather type and finishes may differ so tools used have to match the finishes. Use the Nubuck (N) Leather Problem Solving Guide posted above as reference. Urine under the heading of “Stain Type” is solved by the system step 1 to 7 from left to right. Steps 1 to 5 is the cleaning phase and remains until the result proves satisfactory before moving into leather rejuvenating it as the second phase with step 5 and 6. When dry it is finished with step 7.

Now we start with the cleaning Post #7 picture #5 as follows:

#1. Dry soil removal utilizes tools Eraser-4, Eraser-5 nubuck Brush-2 and a vacuum cleaner to remove surface soiling.
#2. The stain area nap may have been chemically deteriorated or damaged from the urea content that shift the leather protein fiber ionic negative (-ve) or alkaline. Using Eraser-4 first and follows with Eraser-5 to completely removed surface damages that may lighten up the stain area to match the surrounding. This removal is feather out to the entire cushion surface to the edges. Follows with a thorough vacuuming completes the dry soil removal process.

Let have some pictures for inspection before the next step.


Roger Koh
Leather Care Consultant
www.LeatherDoctor.com

#1 Urine stain cleaning
30433044

Roger Koh
04-08-2014, 11:57 AM
Please show pictures of the entire cushion for visual comparison of surrounding areas.

koa
04-08-2014, 06:12 PM
After using the erasers and brush.
#1 Urine stain cleaning
3025

Roger Koh
04-09-2014, 10:33 AM
Tips:

A test require to determine the health of the leather. . .

1. Drip tap water on both the corner of the urine stain area and non-stain cushion area, let it soak in and finger test if you do pick up any tacky or slimy feel on the urine stain area.
2. Please show pictures of the testing.
3. Recommend that pictures is of high resolution to see the condition of the leather better, the previous pictures show deteriorating or damages to the urine stain area and need to be treated cautiously without further exaggerating it.

koa
04-09-2014, 08:00 PM
I was able get some sticky layer off after few attempts of sliding finger over the edge of the urine stain.

#1 Water test urine stain edge.
3041
#2
3042

Roger Koh
04-09-2014, 09:17 PM
The urine stain is deteriorating the leather skip the d'Protein-10 but instead saturate with d'Urine-21 to neutralize the urea content and protonate the protein fiber for a squeaky feel.

Let the d'Urine-2.1 dry for inspection (the odor will dissipate when dry).

Handle with care as the leather will be stiff when dry (no flexing or stress that may cause further cracks).

koa
04-12-2014, 01:42 PM
After d'urine-2.1
#1
3045
#2
3046

Roger Koh
04-12-2014, 02:14 PM
The next stain group to treat are those dark spot that could be protein based.

Use a cotton swab to apply directly to those spots and work with brush and both eraser on these stiffer stains, towel extract and follows with Acidifier-2.0 to pH balance them. We will inspect with pictures when they are dry.

Follow the steps as we are going through the various soiling or stain types by grouping them in sequence.

When these stains spots are well taken care for, the general cleaning will involves Degreaser-2.2 > Acidifier-2.0.

We will still have a general inspection for appearance before we proceed to rejuvenate the leather with Hydrator-3.3 > Fatliquor-5.0 system.


Roger Koh
Leather Care Consultant
www.LeatherDoctor.com
[email protected]
[email protected]

Roger Koh
05-19-2014, 11:07 AM
A higher quality picture will help see more details.

Besides the look, how does it feel when move finger across.

I believe you are continuing the cleaning process accordingly?

koa
05-19-2014, 03:05 PM
I was quite impressed after the first round or treatment. It feels soft and velvet like in most areas, but also stiffer and fine-sandpaper like in some areas - ?from overzealous cleaning.

Updated pictures after cleaning body fluid related stains. These are the more stubborn areas.

#13240
#23241
#33242
#43243
#53244

Roger Koh
05-20-2014, 09:11 AM
>>> Updated pictures after cleaning body fluid related stains. These are the more stubborn areas - but also stiffer and fine-sandpaper like in some areas.


Tips:

For detectable stiffer stains - use a bamboo skewers slice flat at one end making a mini-spatula out of it for doing some heavy scrapping neatly.

The “fine-sandpaper like in some areas” will be relaxed with the help of Hydrator-3.3 up to 72hrs control dwelling and thereafter replenished with Fatliquor-5.0 for softness and strength.

Let see any improvement with pictures.

Is picture #4 the after urine stain cushion?

koa
05-20-2014, 09:46 AM
Picture #4 is a representation of other cushions (not the urine stained)

koa
06-01-2014, 08:15 PM
I used the mini-spatula and even small metal brush from my rotary tool set. Got some of the stiffer stains off but some persist with sometimes slightly depressed pattern like a chemical burn or glued naps.

#1
3298
#2
3299

Roger Koh
06-02-2014, 09:40 AM
Protein stains tends to coagulate and may help to soften up with d'Protein-10 in conjunction with physical agitation.

Use a cotton swab and work neatly on the stain to test how it response.

Remember that its high pH value needs to be pH balance with Acidifier-2.0.

koa
06-02-2014, 12:38 PM
I've done that a couple of times over. Would it be possible to camouflage them with a dye? I'm looking to change the color of the set and open to the any color that would give the best disguise.

Roger Koh
06-02-2014, 12:53 PM
You may have to pick the darkest stain as the lightest color of choice.
In this case you may have to consider Dark-Brown and see if it still covers up the stain.
A test is to have it on white paper and match it against the stain to decide.


Product Information:

3303
Leather Doctor Nubuck-28
Leather Doctor® Nubuck-28 is a translucent hybrid dyestuff that both stains and surface colors to camouflage or obscure unwanted stains by fine airbrushing for nubuck and suede. When prepared surface ready for dyeing is free of any surface contamination, use transparent Aniline-21 to maintain its natural clarity and tactile sensation as priority before resorting to Nubuck-28.

Tips:
For color change, stronger UV strength or camouflaging minor staining issue use Nubuck-28.
For color refreshing from sun fading use Aniline-21
For dye fixing use Leather Doctor® DyeFix-99

Roger Koh
Leather Care Consultant
www.LeatherDoctor.com
[email protected]

koa
06-03-2014, 06:15 AM
Dark-Brown is what we also have in mind, I will go with it.
Would it help to clean the urine stain from inside (suede side) or what is the best way to make the area lighter.
How should I proceed to general cleaning to prepare for the staining and color change.
Thank you very much.

Roger Koh
06-04-2014, 09:25 AM
>>> Would it help to clean the urine stain from inside (suede side)

All penetrated stain cleaning is easier to be done from the suede side as the fiber from this side is looser and stains are much easily removed without much concern if the surface is distorted or abraded. However you will need suede Brush-2 and Eraser-5 for both brushing and erasing suspended soiling particulates.


>>> or what is the best way to make the area lighter.

Need to see pictures to determine the color difference and what cause it darker, the urine itself or products (if you know what was used) that cause it to darker.


>>> How should I proceed to general cleaning to prepare for the staining and color change?

First concentrate on the stain, any solid will still show through, thus have to be removed entirely before we go into general preparation for dyeing.
Color has to be darker than present in-between grains as well as the darkest soften-up stains (dyestuff will not adhere to solid stains).

koa
06-09-2014, 03:33 PM
what is the best way to make the area lighter.
Did not use any product prior to d'Urine treatment. The above pictures below after hydrator 3.3
#1 3353
#2 3352

Roger Koh
06-12-2014, 02:44 PM
>>> What is the best way to make the area lighter. Did not use any product prior to d'Urine treatment. The above pictures below after hydrator 3.3

What you see is one working aspect of Hydrator-3.3 such as:
e) To facilitates colloidal water movement within the inter-fibrillary spaces for wicking foreign soiling particulates to resurface.

This means that at each application and drying cycle suspended soiling particulates is continuously being wick up to the surface to be removed off. Recommended to utilize the “reverse transfer” technique by placing a stretchable paper towel from the kit working with horsehair Brush-1without airspace to trap the soiling particulates to be peel off then still remaining on the leather surface.

A few options to remove the resurface soiling are by a curve edge of coffee wooden stirring stick or nubuck Brush-2 or Eraser-4 or Eraser-5, whichever is convenience and produce the best result.

The area will lighten up once surface-soiling particulates is physical removed. The Hydrator-3.3 application and drying cycle is repeated until no more soiling particulates resurface to completely remove what we may see is just a tip of an iceberg of penetrated soiling.


Please show pictures of your progress!

koa
01-14-2019, 12:23 AM
I am resuming cleaning my nubuck sofa and loveseat, and plan to change the color to dark brown. I used the degreaser followed by acidifier/rinser few years ago but did not get to the fatiliquor phase. We have chair covers over the seating areas since. I think I've gotten all stains I can off, but still have darker stained streaks and lighter overcleaned and decolorized areas. I plan to clean again before dyeing using Nubuck 28 as you previously suggested.

Image 1
8973

Image 2
8974

Image 3 seat cushion with urine stain
8975

Roger Koh
01-14-2019, 11:24 AM
>>> and plan to change the color to dark brown.

Take a look at the suede side, what color is it. If it is brown, then it could be activated with Hydrator-3.3 and redistribute the color to the surface, that will reduce the color difference to a degree with possibility.


>>> I plan to clean again before dyeing using Nubuck 28 as you previously suggested.

Nubuck pigment/dyestuff note:
Nubuck-17 is a transparent dyestuff that stains with penetration.
Nubuck-39 is an opaque pigment coloring that surface coats for better coverage.
Nubuck-28 is a combination of Nubuck-17 and Nubuck-29 that both stains and coats.


>>> I think I've gotten all stains I can off, but still have darker stained streaks

Nubcuk-39 will help to cover these darker streaks.


>>> and lighter overcleaned and decolorized areas.

Hydrator-3.3 and Fatliquor-5.0 helps both to activate and redistribute the dyestuff to surface and saturate hue density to make it less obvious so that color blending difference is much reduced.

Further questions are welcome.

8979
Roger Koh
Leather, Skin & Hair Care System Formulator
Consultant / Practitioner / Instructor / Online-Life-Coaching
online store: www.leatherdoctor.com
forum: www.leathercleaningrestorationforum.com
email: [email protected]

koa
01-14-2019, 01:48 PM
Hi Roger,
Will Nubuck 39 - Tan cover the darker streaks or i should stick with dark brown. I would prefer a lighter color in order to see stain so we could clean promptly.

I think we are going to dye; can I use Fatliquor-5.0 before dyeing.
Thanks

Roger Koh
01-14-2019, 02:54 PM
>>> Will Nubuck 39 - Tan cover the darker streaks or i should stick with dark brown. I would prefer a lighter color in order to see stain so we could clean promptly.

Since you are thinking of using a opaque pigment - white or any shade of white would be my personal choice for a few reasons - 1, maintain the original contrast in color. 2, To maintain the same ambient atmosphere in a interior decorative point of view, a lighter color for a large furniture makes the room bigger and a dark large furniture makes the room looks smaller. An opaque pigment blocks out unwanted pretty well because it is one of the solid color besides black.


>>> I think we are going to dye; can I use Fatliquor-5.0 before dyeing.

The Hydrator-3.3 > Fatliquor-5.0 > Hydrator-3.3 system is highly recommended prior to dyeing/coloring. Dyestuff and coloring need to bind with the protein fiber, if they are dry-rotting and weak, dye or color has nothing solid to hold on or just peel off within the fiber structure. When see most color loss leather a test with a sticky tape often reveal the weaken fibers that cause the poor adhesion and not the dyeing or coloring system itself. Fatliquor-5.0 add strength and suppleness to the nubuck.