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View Full Version : Aniline (Sauvage) - How to restore this 20 years old Aniline Leather Sofa?



Roger Koh
12-01-2011, 04:19 PM
Photos attached. See swatch with drop of distilled water for about 1 minute. Worst is top off cushions; a lot of that is probably saltwater from my fish tank. Other stains most likely assorted protein food stains, beverages. Some body oils. Couch was in southern window area for long time. Must confess I cleaned many areas with woolite and distilled water followed by distilled water rinse. Stains are nearly 20 years old.
Include recommended products for cleaning, preping, and refinishing. Assume variety of stains (protein, perspiration, body oils, and salt stains) and that the sofa has never been cleaned for nearly 20 years. Also, I would like the original color restored and have a leather swatch.

#1
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline1of8.jpg

#2
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline2of8.jpg

#3
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline8of8.jpg

#4
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline3of8.jpg

#5
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline4of8.jpg

#6
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline5of8.jpg

#7
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline6of8.jpg

#8
http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline7of8.jpg

Roger Koh
12-01-2011, 05:22 PM
Picture Observation:

Picture #1
This picture shows the suede side and it’s to confirm that the leather is aniline dyed through – so the matching dyes closest to this shade would be the standard Aniline Dye-21 (Red Brown 159). However it will still depends how the stain turns out, option is to go darker to camouflage the darkest stain or alternatively Micro-pigment can be added to the transparent dye to make it “translucent”. Note that transparent leather has a higher value than translucent or opaque leather finish.

Picture #2
This picture shows the grain side, contrasting with the 20 years of fading; and I believe it will be the intended color to be restored.

Picture #3
This one minute water testing as mentioned shows the leather permeability; due to its original topcoat still intact. Perhaps if left longer may seep through its micro crazing to leave a damp mark. And hopefully the rest of the leather would behave in similar fashion with Aniline Topcoat-79G.

Picture #4 & #5
These pictures show an assortment of stains with rings. Rings usually indicate alkaline stains, where the rings are usually a combination of foreign contamination with the fugitive leather constituents that breaks the hydrogen-bonding. Constituents include the leather dyestuff and fatliquor. Generally after specialty stain removal, the leather pH has to be neutralized to bring back the leather with a positive charge; otherwise the re-dyeing will be patchy. A

Picture #6
This picture show more scratches perhaps inherent which shows that its full/top grain quality with additional topcoat scratches. Since aniline uses transparent dyes with see thru topcoat there is no way to hide the true leather grain characteristic.

Picture #7
Color contrasting different from exposed to concealed

Picture #8
A true aniline leather will have its color intensity variation even though they are facing the same elements – natural beauty in imperfection.

Roger Koh
12-02-2011, 02:53 PM
Stain & Others:

Protein Stains:
Leather is protein fiber, any penetrated protein stains tends to coagulate and becomes part of leather; it has the tendency to turn darker too as it ages. Thus protein stains is one of the toughest to remove. Product recommended for removal is with d’Protein-10 (pH 10), thereafter it is to be neutralized with Acidifier-2.0 (pH 2.0)

Beverages:
Alcoholic beverages have the tendency for rings due to the alcohol effect on the dyes and the fatliquor. Beverages derive from vegetable and plants have the tannin that causes brownish stains. Products recommended for brownish stains are d’Tannin-3.5 (pH 3.5) follows with Rinse3.0 (pH 3.0). The leather need to be hydrated for even appearance with Hydrator-3.3 (pH 3.3) to even out the rings appearance.

Body Oil:
Body oils produce darkening stains and are usually penetrated, it is usually the sweat content of the body oil that cause surfaces damages when it shift alkaline. Products recommended are Degreaser-2.2 (pH 2.2) follows with Rinse-3.0.

Salt Water:
Salt water has an average pH of 7.5 to 8.5, while the pH of average leather is from 3 to 5. Thus salt water reacts with the leather pH and charges it negative. The leather constituents like dyestuff and fatliquor are negative too – thus like magnet “like poles repels” – denatures the leather. Product recommended to recharge the leather positive is to use a pH 2.0 (Acidifier-2.0) – otherwise the new dyestuff would not hydrogen-bond with the protein fibers.

Woollite:
Woolite has the similar pH range as that of salt water between 7.5 and 8.5. To keep the leather protein fiber positively charged, solution used for its care should be around pH 3 – 5. To keeps the leather its chemistry integrity.

Stains are nearly 20 years old:
Old stain still remains as stain may have been set as part of the leather – thus the specialty products helps to remove them.

Roger Koh
12-02-2011, 03:17 PM
These are the recommended products for restorative cleaning prior to re-dyeing...
Products would include Kit A3.ps + d’Tannin-3.5 + Degreaser-2.3 + Leather Eraser-4

It would be from the stain removal, restorative cleaning, leather pH conditioning that will decide how best to dye it as discuss (picture #1)


http://i300.photobucket.com/albums/nn4/Rogerkoh/A3ps-2.jpg
Leather Doctor® Kit A3.ps : Aniline Leather Protein Based Stain Removal Kit

■ Aniline Leather Protein Based Stain Removal System
Protein stains tend to coagulate that requires a high alkaline product like d’Protein-10.0 to break it up; thereafter the high alkalinity is neutralized with a pH 2.0 acidifier. Compound protein stains like blood would require d’Tarnish-1.3 with its reducing bleaching reaction to further work out the other rusty iron component of the stain found in Kit-A3.bs. Compound food stains with tannin coloring like mustard and meat sauce would require d’Tannin-3.5 with its reducing bleaching reaction to work out the tannin colored stain found in Kit-A3.ns. With penetrated stains it’s common for a topcoat touchup thereafter with Topcoat-79G found in Kit A3.dr.
Instructions
1st Phase Protein Stain Removal:
1] Dried and caked stain is gently brush agitated to break it up.
2] Apply d’Protein-10.0 direct to the stain and brush agitates to cause the stain to begin loosening and start running.
3] Towel extracts and repeats application, agitation and extraction until the stain is removed.
4] Spray Acidifier-2.0 and towel extract until towel shows clean to a healthy squeaky clean.
2nd Phase Hydrating:
1] Spray Hydrator-3.3 with help of foam brush to penetrate the leather to even out appearance.
2] To further activate dormant dyestuff to resurface, the entire seat is wrapped with clear cling wrapper to control evaporation for an overnight dwell.
3] Towel extract until it shows clean and it’s ready for fatliquoring.
3rd Phase Fatliquoring:
1] Spray Fatliquor-5.0, spread with foam brush for an even appearance without the blotchiness and let natural dry.
2] Repeat application in between drying until it’s saturated.
3] The fully saturated leather is left for slow natural drying for extra softness.
4] Dry brush wicks up residue and inspect for satisfaction.
4th Phase Dry Preparation:
1] Topcoat damaged surface is work over frees of foreign residues with Eraser-4 prior to topcoat it.
5th Phase Topcoat Application:
1] Topcoat-79G first coating is applied by lint free towel or foam brush with optional 1000 - 1500 grit fine sanding in between dry coating.
2] Airbrushing is optional to avoid streaks.
6th Phase Non-stick Rub Resistant Protection:
1] Spray leather Scent-B, spread with lint free towel and it’s ready to use when dry.


■ Aniline Leather Tannin Stain Removal System
A dual action leather-safe system that works with penetrating, lubricating and suspending action in conjunction with reduces bleaching effect.
Instructions
1st Phase Removal:
1] Shake well, spray d’Tannin-3.5, horsehair Brush-1 agitate and towel extract until it shows clean.
2] Repeat spray and let natural drying for chemical reaction to take effect.
3] Brush off dry residue, rinse with Rinse-3.0 and inspect for satisfaction; otherwise repeat as necessary.
2nd Phase Hydrating:
1] Spray Hydrator-3.3 with help of foam brush to penetrate the leather to even out appearance.
2] To further activate dormant dyestuff to resurface as an option, the entire seat is wrapped with clear cling wrapper to control evaporation for an overnight dwell.
3] Towel extract until it shows clean and it’s ready for fatliquoring.
3rd Phase Fatliquoring:
1] Spray Fatliquor-5.0, spread with foam brush for an even appearance without the blotchiness and let natural dry.
2] Repeat application in between drying until it’s saturated.
3] The fully saturated leather is left for slow natural drying for extra softness.
4] Dry brush wicks up residue and inspect for satisfaction.
4th Phase Non-stick Rub Resistant Protection:
1] Spray leather Scent-B, spread with lint free towel and it’s ready to use when dry.


■ Aniline Leather Degreasing System
Degreasing process involves two steps; first is the sufficient penetration of the degreaser to react with the grease and second is to cause a wicking action to bring out the grease. This process may be repeated depending on the depth of grease penetration. An advance technique is to cling wrapped the degreaser to control evaporation for a more effective dwell time.
Instructions
1st Phase Degreasing:
1] Warm up Degreaser-2.2 and shake very well until it turns to an opaque gel.
2] Apply direct and agitate with horsehair Brush-1 and/or Eraser-4 and towel extract until it shows clean.
3] Penetrated stains may require a deeper penetration, a dwell time of 5 to 30 minutes or before it dries for chemical reaction to occur, follows with towel extraction. Severe cases can be saturated and cling wrapped to control evaporation for a longer overnight dwell.
4] Suspended residue is to be rinse with Rinse-3.0 and towel extract until it shows clean.
5] Let natural dry for suspended particulates to wicks up, erase with Eraser-4 and inspect for satisfaction, otherwise repeat as necessary.
2nd Phase Stripping:
When topcoat damages are revealed, it is recommended that the entire panel is stripped to ensure an even appearance for topcoat refinishing. This is best done after the degreasing process.
1] Apply optional Stripper-2.3, scrub with leather Eraser-4 and towel extract to remove the topcoat damaged panel entirely.
2] Optional is use leather Razor-60 for shaving off topcoat, smoothen with 1000 – 1500 grit wet/dry sanding disc in conjunction with Rinse-3.0 with repeat towel extraction.
3] Spray Rinse-3.0 to remove topcoat residues to a squeaky clean.
3rd Phase Hydrating:
1] Spray Hydrator-3.3 with help of foam brush to penetrate the leather for an even appearance.
2] To further activate dormant dyestuff to resurface, the entire seat is wrapped with clear cling wrapper to control evaporation for an overnight dwell for an even appearance. The relaxed leather structure allows the creases and wrinkles to be further worked out for better appearance.
3] Towel extract until towel shows clean prior to immediate fatliquoring.
4th Phase Fatliquoring:
1] Fatliquor-5.0 follows the same procedure as the Hydrator-3.3, with in between drying application as moisture evaporates until it’s saturated.
2] The fully saturated leather is left for slow natural drying for extra softness.
5th Phase Dry Preparation:
1] Inspect for complete removal of existing topcoat, texture roughness is to be smoothen with sanding (1000 – 1500 grit).
2] The leather surface is work over free of residues with Eraser-4 to an even appearance.
6th Phase Topcoat Application:
1] First coating is applied by lint free towel or foam brush with optional 1500 grit fine sanding in between dry coating for smoothness.
2] Airbrushing is optional for a professional result with in between fine sanding to achieve the desired smooth feel.
7th Phase Non-stick Rub Resistant Protection:
1] Spray Leather Scent-B, spread with lint free towel or foam brush and it’s ready to use when dry.

mikeg
12-05-2011, 02:05 PM
Sounds good. I am ready to order products. Please tell me how.

Should I send swatch for exact color match? Or will off-the-shelf color work?

Regards,

Mike

Roger Koh
12-06-2011, 10:16 AM
Mike, for ordering need you to email your shipping address for us to prepare you a PayPal invoice.

Color:
Yours is using “transparent” color, everything on the surface will see through, the beauty and the stains – so unless the stains are fully removed you still see the stains.

1] To have your choice of existing color, any stain darker has to be removed.

2] Other options will be to increase the color intensity by adding dark brown or black to camouflage whatever stain is still left behind.

Note:
Dye stains the leather surface, but remembers that the topcoat that resist absorption will also resist the dye – just like picture #3
You may have uneven absorption thus result in blotchiness – another alternative is to “coat” the surface by adding up to 30% of Adhessor-73 to the Aniline Dye-21 – so that now it will coats over the existing topcoat as well.

Other Color Consideration:
Hydrating with Hydrator-3.3 with overnight dwell will activate the dormant dyestuff to resurface – this process will help intensify the color further, narrowing the difference for easier color re-dyeing.

Fatliquor will also add intensity to the leather prior to re-dyeing.

Conclusion:
In transparent dyes “what you see may not what you get” – as mentioned other factors mentioned above will influence how the color will appears as it only amplify the “beauty” and “stains” already exist. Color intensity is also build by layers – exactly just like water coloring versus oil painting.

Further questions you may have?

Roger Koh
[email protected]

Roger Koh
12-06-2011, 10:21 AM
These are the products you may need for the re-dyeing, assuming you do not need any repairs...



http://i300.photobucket.com/albums/nn4/Rogerkoh/Auxiliary3-1.jpg
Leather Dyeing & Coloring Auxiliary (3):
Leather Adhesion Coating,
Leather Topcoat Crosslinker &
Leather Colorcoat Flow Controller.


Leather Doctor® Adhesor-73
It’s an auxiliary for Pigmented and Aniline leathers refinishing.
This is an aqueous compact resin adhesion promoter to ensure proper adhesion prior to color coating.
It's also added to Aniline Dye-21 for dye coating absorption resistant areas to reduce color blotchiness.
And it’s also used after WaxEffect8.6 prior to top coating.
This product is also available in concentrate to be cut with distilled water at a ratio of 1: 1.
Thus a quart makes 2 quarts of Ready-To-Use product to save on shipping.
Ready-To-Use packing sizes are available in 60ml, 250ml and in Quart.
Concentrate packing sizes are available in quart (2 quarts).
Email [email protected] for prices.
Note:
Strip clean of foreign contamination prior to application – use Prep-7.7 > Cleaner-3.8 > Rinse-3.0.
Instruction:
1] Shake well, hand padding preferred to ensure better anchorage for non-absorbent leathers.
2] Fine airbrushing for absorbent leathers to reduce patchiness.
3] Let dry naturally or speed dry with blow dryer.
3] Proceed with choice of further coating.

Leather Doctor® Thickener-48
This is an auxiliary aqueous carboxylated acrylic co-polymer thickening agent to stabilize color during spraying.
It’s to adjust the flow of color to improve hold-up especially on vertical panels and antiquing two-tone fashion leathers.
It is highly effective and maintains the viscosity over the period of use.
This product is available in 60ml and 120ml.
Email [email protected] for prices.
Instruction:
1] Add 5 to 15% of total weight of color and stir simultaneously while adding.



http://i300.photobucket.com/albums/nn4/Rogerkoh/AnilineSystem12.jpg
Aniline Leather Dyeing System (12):
Aniline Black Dye,
Aniline Orange Dye,
Aniline Red Dye,
Aniline Red-Brown Dye,
Aniline Yellow Dye,
Aniline Dark-Brown Dye,
Aniline Rubine Dye &
Aniline Blue Dye.
Aniline Natural Topcoat,
Aniline Waxy Matte Topcoat &
Aniline Gloss Topcoat.



Leather Doctor® Aniline Dye-21
It’s for staining absorbent aniline leathers.
This is a new generation aqueous transparent staining aniline dyestuff that is more lively and brilliant than most liquid dyes.
It’s to provide a more superior light fastness and fades resistance than most standard liquid dyes.
For coating aniline leathers that has existing topcoating; add up to 30% Adhesor-73 to even out appearance.
Standard colors available in Black-115, Orange-157, Red-180, Red-Brown-159, Yellow-128, Dark-Brown-124, Rubine-113 and Blue-119.
This product is also available in concentrate to be cut with distilled water at a ratio of 1: 8.
Thus a 120ml makes 1.14 quarts of Ready-To-Use product to save on shipping.
Ready-To-Use packing sizes are available in 60ml, 250ml and in quart.
Concentrate packing sizes are available in 120ml (1.14), 250ml (2.37) and quart (9 quarts).
Email [email protected] for prices.
Instruction:
1] Prep clean - use Prep-4.4 follows by Cleaner-3.8 then Rinse-3.0.
2] When prep clean using Degreaser-2.2 either rinse with Acidifier-2.0 for bleeding control or with standard Rinse-3.0.
3] Inspection when dry – use leather Eraser-4 to remove wick-up soiling particulates.
4] Shake well before application.
5] For adhesion surface coating - add 10 to 30% Adhesor-73 (less is more natural).
6] Airbrush to even out the color avoiding streaks or drips.
7] Blow dry in-between coats until desired result is achieved.
8] Leather rejuvenation – use Hydrator-3.3 follows with Fatliquor-5.0.
9] Topcoat protection to match original luster - use Aniline Topcoat-89N(natural), Aniline Topcoat-59M (waxy matte) or Aniline Topcoat-79G (gloss).

Leather Doctor® Aniline Topcoat-79G
It’s a gloss finish for upholstery Aniline leathers.
This is an aqueous fine particular size urethane resin emulsion topcoat.
It’s to protect aniline dyestuff with excellent toughness and flexibility.
This product is also available in concentrate to be cut with distilled water at a ratio of 1: 1.
Thus a quart makes 2 quarts of Ready-To-Use product to save on shipping.
Ready-To-Use packing sizes are available in 60ml, 250ml and in quart.
Concentrate packing sizes are available in quart (2 quarts).
Email [email protected] for prices.
Instruction:
1] Apply after Aniline Dye-21; otherwise prep clean - use Prep-4.4 follows with Cleaner-3.8 then Rinse-3.0.
2] Pad or fine spray without streaks or drips.
3] Non-Stick, Rub-Resistance buttery-feel protection with a classic leather scent - use Protection-B+ (leather Scent-B).

mikeg
12-07-2011, 09:13 PM
I think I understand what you are saying regarding stains.

I can live with the stains as long as the restoration brings the leather back to its original suppleness. The swatch is buttery - I love it.

Transparent dye process is fine as long as the color intensity gets close to original.

Roger Koh
12-08-2011, 10:06 AM
I think I understand what you are saying regarding stains.

Stain removing is a challenge, not so bad as we have a range of specialty products to handle them; very unpredictable but still they have to go ultimately – see this Aniline Leather Problem Solving Guide - that’s the challenge!


http://i300.photobucket.com/albums/nn4/Rogerkoh/Aniline13-LPG.jpg
Leather-Safe Aniline Leather Problem Solving Guide-A9


I can live with the stains as long as the restoration brings the leather back to its original suppleness.

To bring back the original suppleness, we have to do what was originally been done in the tannery – If the leather structure (thickness of the leather about 1mm in thickness) can be evenly hydrated after the stain removal and restorative cleaning and pH balancing back to the leather neutral pH of 3 – 5. We can fatliquor replenish it as soft as you wish – not a problem if you follow instruction!


The swatch is buttery - I love it

Buttery softness is referring to the overall leather suppleness; while buttery-feel is referring to the surface tactile-feel. You can have both with Fatliquor-5.0 for the former and with Protection-B+ for the latter. Besides you have the extra bonus of the 18th Century unforgettable classical leather scent – fresher than show-room condition.


Transparent dye process is fine as long as the color intensity gets close to original.

Remember that the dye was stain in the tannery prior to topcoat protecting it; now that the soft urethane protection is on top, how do the dye able to penetrate these topcoat to re-dye the leather again? Two possibility for an even dyeing result; it’s either removing the existing topcoat entirely for an even re-dyeing penetration or coating on top of the topcoat. When you go through the cleaning process you will realize that the used areas are more easily permeable than the non-used areas. The more absorbent areas will receive more dyestuff, thus will result in deeper color intensity, while the non permeable areas will resist the dyes – thus result in unevenness as the result to the existing uneven topcoat at different areas. A solution to overcome this difference in absorption rate is to “coat-dye-it” – this is done with addition of Adhesor-73 up to 30% (less is more natural) to the Aniline Dye-21. Now the higher viscosity dyestuff will coat the existing topcoat for a more even appearance.

We can discuss how to remove the existing topcoat entirely if you wish to do so. The advantages is the more natural result when comes to re-dyeing.

In such unpredictable 20 years of staining situation – I would only know for sure if I should get close the color back to the original until I re-inspect the situation prior to re-dyeing it. Adding Dark Brown to the Red Brown may be a good consideration to test it out. If you are not sure if you will like the color – spray/pad the dye over a clear plastic sheet and place over the leather – what you see is what you will get!

Roger Koh
[email protected]

Roger Koh
12-09-2011, 05:43 PM
To recap, I am ok with having residual stains after the cleaning process and want to stay with the original manufacterers finish as much as is possible. So aniline dye with (i'm guessing here) some protective finish.

1a] Original finish is achieved by removing the existing topcoat entirely, re-dyeing then re-topcoating in similar sequence of original processes.

1b] Otherwise, an option is to coat over the existing topcoat with the help of Adhesor-73 (your choice). The feel is heavier due to the additional of Adhesor-73 to the Aniline Dye-21

Either the above 1a] or 1b] topcoat protection is mandatory using Topcoat-79G (gloss)


Based upon my pictures and swatch are you able to guess the type of leather (aniline wax, pull-up, etc)?

This is most likely the standard aniline finish – with Topcoat-79G (gloss) + Protection-B+.
Could possibly be but most unlikely a waxed finish – with Topcoat-59M (waxy matte) + Protection-W+.
Not possible is a wax pull-up – with Wax Effect-8.6 + Adhesor-73 + Topcoat-79G + Protection-D+.
Out of the question if this is an oil pull-up – with Oil Effect-2.8 + Adhesor-73 + Topcoat-79G + Protection-B+
Seldom a sofa is Pure Aniline -with Topcoat-89N (natural) + Protection-S+.

Roger Koh
12-09-2011, 06:04 PM
Need your recommendation on finishing products based upon keeping couch close to original look.

To restore to original look recommendation is as follows:
1. All stains has to be removed, otherwise the stain will show through.
2. Dyes will only stain the protein fiber and not the stain, unless they are coated with addition of Adhesor-73.
3. Dye is stain by hydrogen-bonding, that is the protein fibers has to be positive charged with help of Acidifier-2.0 for the new negative dyestuff to bite the protein fiber.
4. The intensity of color is build by successive layers.
5. Do not expect a mono-tone appearance – that is only achieve with using opaque “Micro-Pigment” converting this aniline leather to a semi-aniline leather.
6. The products you may need is seen at above post.

mikeg
12-27-2011, 12:11 PM
Finished cleaning one cushion; applied fatliquor with foam brush several times as it was absorbed into leather;

What is approx. "dry" time for fatliquor at room temp?

Can too much be used and how would you know and would the leather rectify itself over time?

Note dark and light areas of cushion in photo.

regards,

http://i300.photobucket.com/albums/nn4/Rogerkoh/Mike-fatliquor.jpg

Roger Koh
12-27-2011, 07:14 PM
Finished cleaning one cushion; applied fatliquor with foam brush several times as it was absorbed into leather;
What is approx. "dry" time for fatliquor at room temp?

With a good air circulation and lower humidity, the drying time will be shorter; however still takes overnight drying.
Note that the slower the drying, the softer the leather would be.


Can too much be used and how would you know and would the leather rectify itself over time?

The leather naturally takes up lesser with each application and may reach a point that it will not absorb anymore.
If you have a moisture meter you could do your own reading just like for wood – should average 14% when dry to the touch.
If too much is applied and the temperatures goes below 10 degrees Celsius - It may manifest as white residue – Apply heat with hair dryer and it will be reabsorbed into the leather structure – Overtime it will diminish as VOC (volatile organic compound) – Periodic top-up will keep the leather at its optimum level with suppleness, perpetually.


Note dark and light areas of cushion in photo.

The dark areas are typically damaged topcoat. These are areas that should be towel extracted while damp throughout the wet processes including during the hydrating and the fatliquor replenishing. When crispy dry they should be erased with Eraser-4 without a trace of soiling particulates.

See the after Eraser-4 pictures, before “dry prep” into color refinishing.

Roger Koh
12-29-2011, 04:59 PM
Pictures taken after extensive cleaning, follows with rinsing; as clean as it will ever get.

Leather hydrated then immediate fatliquoring with foam brush. Center panel has 3 hydrate/fatliquoring coats; outer panel two coats. Back zipper panel is original finish with 1 fatliquor coat, thus fairly representative of what it should look/feel like.

Center panel sanded one day after application with 1500/3000 grit diamond pad. It became softer than when untreated, but still rougher than undisturbed zipper panel (very buttery). Sanding should be done when dry, Yes?

Can’t tell if dormant dyestuff is resurfacing or fatliquor is darkening surface. Hydrating treatment evaporates at room temperature even when covered with plastic wrap. Perhaps not generous enough with hydrating; running short of it for entire couch.

Please comment on use of glycerin and distilled water as a hydrator.

#1
http://i300.photobucket.com/albums/nn4/Rogerkoh/169.jpg

#2
http://i300.photobucket.com/albums/nn4/Rogerkoh/174-1.jpg

#3
http://i300.photobucket.com/albums/nn4/Rogerkoh/177.jpg

Roger Koh
12-29-2011, 11:46 PM
Pictures taken after extensive cleaning, follows with rinsing; as clean as it will ever get.

Wish you have a before picture for direct comparison on how much you have accomplished. These pictures should have been taken after hydrating > Eraser-4 for inspection (before fatliquor). I believe it can be further improved from another re-clean accordingly: Prep-4.4 > Cleaner-3.8 > Rinse-3.0 > Hydrator-3.3 > Eraser-4 > “Picture of Inspection”.


Leather hydrated then immediate fatliquoring with foam brush. Center panel has 3 hydrate/fatliquoring coats; outer panel two coats. Back zipper panel is original finish with 1 fatliquor coat, thus fairly representative of what it should look/feel like.

This phase of fatliquoring commences only after utmost satisfaction is accomplished as mentioned above.


Center panel sanded one day after application with 1500/3000 grit diamond pad. It became softer than when untreated, but still rougher than undisturbed zipper panel (very buttery). Sanding should be done when dry, Yes?

Sanding can both be done during wet with Rinse-3.0 to remove healthy untouched topcoat to even out the panel (fresh topcoating will gives a better appearance even though dyeing is opt out). Or it can be done dry inbetween topcoat application to smoothen the surface. Sanding is not recommended direct on leather worn of topcoat (the more you sand the leather the rougher it becomes); use Eraser-4 instead to remove soiling particulates, it can be used wet in conjunction with Rinse-3.0 or alone when the leather is crispy dry. The undisturbed zipper panel (very buttery) is where the topcoat is still there. The center panel buttery softness will return if hydrating is effective to relax the leather; fatliquoring to replenish what makes leather soft, supple and strong when dry; and topcoating to improve the handle with Protection-B+ to imparts the buttery smooth feel. Anyway I am just pointing to the finish line that our desire for the leather finish is attainable, but not there yet.


Can’t tell if dormant dyestuff is resurfacing or fatliquor is darkening surface.

Pictures still show traces of soiling that need to be further wick-up. It can be towel extracted periodically while the moistures brings the soiling up to the surface and work with Eraser-4 when crispy dry. Repeat hydrating if necessary to continuous brings these soiling to the surface and erasing when dry. Eventually you will have a soil free surface.


Hydrating treatment evaporates at room temperature even when covered with plastic wrap. Perhaps not generous enough with hydrating; running short of it for entire couch.

If you do not experience moisture oozing out of the leather when gently press with thumb and finger; it is insufficient to do its works accordingly. Use the kitchen food cling wrap to seal it tight.


Please comment on use of glycerin and distilled water as a hydrator.

All liquid will wet the leather, but not all these liquids qualify as a leather-safe hydrator – excess of liquid of the wrong type will stiffen the leather as experience in most water damaged situation.
A leather-safe hydrator need to have a pH range from 3 to 3.5, so if this mixture can achieve within this pH range it may qualify, but...
A leather-safe hydrator is in fact a surfactant that has penetrating power to separates the fibrils within the leather thickness and moves foreign contamination to the surface – shake it up to see if it lathers up, and...
A leather-safe hydrator is at this acidic pH range to ionic charge the leather protein fibers positive below its isoelectric point – so that all the negatives leather constituents including the fatliquor will hydrogen-bond with the protein fibers, just like magnets “unlike poles attracts”.
Any excessive liquid pH above the isoelectric point of the leather protein fibers averaging 4 will cause the destabilizing of the leather – often manifest as bleeding, and drying with stiffness.

Glycerin pH is mostly 7 and above depending on the types; distilled water averages 5.2. How do you attain a pH of 3 to 3.5 – unless you add Acidifier-2.0 to the mix?
Glycerin has the ability to lubricate but what hydrating requires is the penetrating power to separate and relax fibers.
Glycerin is used for its ability to attract moisture to have a wet look and may have a sticky residue, not sure if it turns browning when exposed to sunlight.

What we do is what practice in a modern tannery, although products are proprietary the principle and the sequence of process is universally acceptable with the fact of science and the art of practice.