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Thread: Stains and body oil on aniline or semi-aniline leather chair

  1. #1
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    Default Stains and body oil on aniline or semi-aniline leather chair

    Hey Roger,
    Here are some pictures of a leather chair I need to clean and recondition. I would like to clean the stains and body oils without having to recolor if possible. What are your instructions?
    Thank you,
    Frank
    Attached Images Attached Images   

  2. #2
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    >>> clean the body oils

    Body oil, grease and sweat darken the leather as the contamination is being absorbed. It is the sweat that dries up the leather. So the procedure during the wet cleaning process deep into the leather structure is by Degreaser-2.2 > Acidifier-2.0 > Hydrator-3.3 and while the leather is still damp about 25% moisture content Fatliquor-5.0 in introduced with a few repeats until fully saturated. It is important not to allow the leather to be fully dried without Fatliquor-5.0 otherwise “Van der Waals” or “London Forces” sets in and the leather stiff up and cracks may accelerate. Slow natural drying also produces more supple leather.

    For your general readings . . .
    Leather Doctor® Degreaser-2.2 is a pH 2.2 leather-safe water-based degreaser with dye bleeding control. It is formulated for degreasing leather of penetrated oil, grease and sweat stains from skin, and hair contact, especially the headrest and armrest of upholstery, collar and cuffs of garment, handles of bag including steering wheel. It works best in conjunction with Rinse-3.0 to rinse surface soiling or Acidifier-2.0 for penetrated soiling. Hydrator-3.3 deep structural saturation further helps in releasing and moving suspended soiling by squeezing over a highly absorbent cotton towel until towel shows clean. The remaining suspended soiling is further moved by saturation and allows wicking by reverse-transfer through a tight surface contact with Towel-5. To remove penetrated soiling completely off the surface will require the three steps of penetration, suspension and extraction by Degreaser-2.2 > Acidifier-2.0 > Hydrator-3.3 system.

    A- Dry Soil Removal with Brush-1 & Eraser-4 for leather, Brush-2 & Eraser-4 for nubuck and Brush-3 & Eraser-5 for suede: A1- Brush with leather Brush-1/2/3. A2- Erase with leather Eraser-4/5. Then, vacuum nubuck and suede of loose soiling accordingly prior to degreasing.
    B- Degreasing with Degreaser-2.2: B1- Shake Degreaser-2.2 until it gels, saturate to reach penetrated soiling with appropriate above mentioned Brushes and Erasers and extract with dry terry cotton towel until towel shows clean. B2- Re-apply and allow dwelling 5 to 60 minutes or before it dries for a complete soiling suspension to occur and towel extract until it shows clean. B3- Immediately proceed to C(a) or C(b) for surface rinsing.


    C1- Surface Rinsing with Rinse-3.0: C1:1- Spray Rinse-3.0 and use dry terry cotton towel to extract until towel shows clean, let dry and proceed to F. C1:2 - To reduce tackiness due to prior alkaline over-exposure proceed to use Acidifier-2.0 C2.

    C2- Structural Rinsing with Acidifier-2.0:
C2:1- Spray Acidifier-2.0 to saturate penetrated soiling and use dry terry cotton towel to extract until towel shows clean, let dry and proceed to F or D for extra structural wet soil removal.


    D - Extra Structural Wet Soil Removal with Hydrator-3.3: D1- Spray Hydrator-3.3 to again saturate penetrated soiling and use dry terry cotton towel to extract until towel shows clean. D2- Extra extraction is by repeat saturation and indirect squeezing through a dry towel with an appropriate spatula until towel shows clean and let natural dry to inspect for satisfaction or proceed to E- Structural soil reverse-transfer technique.

    E- Structural Soil Reverse-Transfer Technique with Towel-5: E1- Leather structure is again saturated and Towel-T5 is wet-stretch out with Brush-1 void of air space and let dry naturally. E2- When it is crispy dry peel off Towel-5. E3- Proceed to dry soil removal (F).
    F- Dry Soil Removal with Brush-1 and Eraser-4:
F1- Lightly stretch the leather to open up the pores. F2- Brush with leather Brush-1.
F3- Erase with leather Eraser-4.
F4- Inspect for satisfaction, otherwise repeat or proceed to other revealed class of stain removal system.

    When soiling and stains are removed to satisfaction, proceed to leather rejuvenation with Hydrator-3.3 > Fatliquor-5.0 > Hydrator-3.3 system.

    Tips:
    Optimum fatliquor (fat and oil) moisture content in dry healthy leathers is up to average14% when read with a leather moisture meter or an equivalent. Existing cracks magnifies when fatliquor moisture content falls below 7% level when dry for most leather and especially for the naked vegetable-tanned leathers popularly known as Vachetta.
    Leather by nature is both hydrophilic and oleophilic and easily absorb body contact oil, grease and sweat. Penetrated and prolong soiling contamination that has high sweat content tends to denature the leather that manifest as stickiness, with a dye-bleeding problem. Leather-safe degreasing with charging the protein fiber ionic positive is the science and logic approach to effective degreasing. In additional to a deep non-hazardous and non-toxic degreasing, the leather is reverted from denaturing into rawhide. Degreasing at a low pH of 2.2 below the average iso-electric point (pI) of leather revitalize the ionic attraction. The amphoteric protein fiber returns to its ionic positive attraction towards the negative leather constituents that includes the tanning agent, dyestuff and fatliquor. When such contamination is thereafter rinsed with Acidifier-2.0, the leather returns to a healthy squeak with reduce dye bleeding in a leather-safe waterbased system. Moreover, the leather is softer when dry without leaching out of its original fat and oil as associated with a dry solvent system.


    >>> clean the stains

    It look to me that these may be aged “blood” stain as most of them have an outer ring

    For your general readings . . .

    Leather Doctor CleanProtein-9.9 is a pH 9.9 cationic specialty solution developed for removing blood, body-discharge, milk, cream, ice cream, egg, meat juices, vomit, perspiration, urine and other protein based stains. In addition, any staining that comes from a living animal or person will probably need this product in the removing process. It is mandatory to follow with Acidifier-2.0 to rinse and pH balance the alkalinity as a holistic leather-safe system, thus safe for all leather, vachetta, suede, nubuck, hair-on, woolskin and feather. Compound stains are further treated with KillUrine-2.2 for urine stains, CleanTarnish-1.3 for bloodstains and CleanTannin-3.5 for plant and vegetable related coloring.

    Instruction:
    1 Inspect and remove all caked and surface deposit prior to application.
    2 Apply, agitate and extract with repetition until the stain is removed.
    3 Neutralize and rinse with mandatory Acidifier-2.0 until towel shows clean to a squeaky feel.

    Tips:
    Bloodstains tend to coagulate and bind tenaciously, thus using an appropriate tool like a bamboo skewers helps to dislodge the stain.
    BLOOD STAINS is a protein based stain that has the tendency to coagulate with the leather protein fiber and makes removal tougher than other protein stains even working with appropriate leather protein stain removal. It has also the iron component that will get darker in color when it ages. Dried blood stains will range from tan to black with an outer ring. When the protein component is first removed with CleanProtein-9.9 and rinse with Acidifier-2.0 neutralizing effect, the other secondary iron component present will need to go through another reduction-oxidation (redox) chemical reaction again when dry and neutralized with Basifier-8.8. Thereafter, other option available is by leather rejuvenating to revive color intensity or color refinishing to camouflage remaining residue from compounded and failed attempt stains. Hydrogen Peroxide, an example is not recommended for bloodstain removal on leather, as oxidation will “cook” the protein leather fiber and the bloodstain as well, altering their original chemistry, thus remaining stains may not match up with the chemistry of the mentioned products formulated for.

    NUBUCK BLOOD STAINS REMOVAL – Instruction:
    1. If the blood has dried and caked, the build up area should be gently brushed with Nubuck Brush-2 or using a wooden ice-cream stick as spatula.
    2. Apply CleanProtein-9.9 to the center of the stain and start massaging gently with Brush-2 or Spatula to breakup the stain.
    3. Continue applying (control to not to overflow too far over the stain edge).
    4. Agitate and towel extract until towel shows clean.
    5. Neutralize and rinse off remaining residue with Acidifier-2.0 until towel shows clean.
    6. Allow to dry for inspection.
    7. Any traces of iron (rust) coloring component remaining is removed with CleanTarnish-1.3.
    8. Apply neatly onto the stain and let it natural dry to do its reduction-oxidation (redox) reaction.
    9. Inspect when dry for satisfaction or repeat treatment.
    10. Satisfied result will need immediately neutralized and rinse off with Basifier-8.8.

    Tips:
    Option is by leather rejuvenating (Hydrator-3.3 > Fatliquor-5.0) any faded leathers to intensify it with camouflaging help.
    Another is by color refinishing to improve appearance.


    Note:
    In most cases working with blood stain on "Aniline" the delicate finishes are commonly removed together with the stain.
    Recommend you do a testing on a piece of scrap to experience the outcome of the removal before you attempt this project.


    Most body oil, grease and sweat removal will also involved in at least a topcoat refinishing, otherwise complete with dye coating refinishing.


    Roger Koh
    Leather Care System Formulator
    Consultant / Practitioner / Instructor
    web: www.leatherdoctor.com
    forum: www.leathercleaningrestorationforum.com
    email: roger@leatherdoctor.com

  3. #3
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    Thank you Roger. When you say a healthy squeak do you mean when the leather is wet or dry?

  4. #4
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    Healthy leather when wet will feels squeaky.

    Denatured leather when wet will feels tacky or slimmy.

    Denatured leather may be restored when the protein leather fiber is given a dose of ionic positive (+ve) charge with Acidifier-2.0 and in most cases returns to its pH chemistry integrity - a healthy squeaky feel when wet.

    Denaturing of leather is reverting the leather back to raw hide, as all the leather constituents are all leached out or hydrogen-bonding weakens.

    The main leather constituents are the tanning agent, dyestuff and fatliquor.

  5. #5
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    Ok. Based on what I have read, Hydrator 3.3 allows greater penetration and wicking of products especially when stains are deep or have been present for long periods of time.
    For body oils, Can I apply Degreaser 2.2 and apply Hydrator 3.3 on a paper towel together and then cover with cling wrap and a towel and let it dwell for 24-48 hours?
    For the blood stains, Can I apply Clean Protein 9.9 and soak Hydrator 3.3 on a paper towel, cover with cling wrap and a towel and let it dwell for 24-48 hours to remove long time blood stains?

  6. #6
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    >>> For body oils, Can I apply Degreaser 2.2 and apply Hydrator 3.3 on a paper towel together and then cover with cling wrap and a towel and let it dwell for 24-48 hours?

    Why Acidifier-2.0 (pH 2.0) is used as rinse, as well as charging the protein fiber ionic positive (+ve). Body oil, grease and sweat areas when wet does not have a healthy squeaky feel, it often feels tacky or in worst cases feel s slimy, is a sign of leather denaturing. In such situation it will always dries stiff and leads to cracks. With the loss of a strong ionic positive (+ve) charge, the ionic negative (-ve) fatliquor does not hydrogen-bond effective, thus leather suppleness may also be compromised. Rectifying the leather pH chemistry integrity is an important factors prior to fatliquoring it. Recommend Degreaser-2.2 > Acidifier-2.0 for surface rinse and Hydrator-3.3 for leather structural colloidal movement.


    >>> For the blood stains, Can I apply Clean Protein 9.9 and soak Hydrator 3.3 on a paper towel, cover with cling wrap and a towel and let it dwell for 24-48 hours to remove long time blood stains?

    Blood main component is protein, leather fiber is also protein based, thus they bind and coagulate and it is tough to break it down without physical agitation. Unless it is fresh where the protein has not coagulates or cured. Old stain has the iron components as well and will need a redox (reduction-oxidation) reaction with CleanTarnish-1.3. Basifier-8.8 is mandatory to neutralize the low pH of 1.3 back to average pH 3 to 5. Otherwise the leather will deteriorate. Old blood stain in most removal will require a refinishing to look good again.

    Roger Koh
    Leather Care System Formulator
    Consultant / Practitioner / Instructor
    web: www.leatherdoctor.com
    forum: www.leathercleaningrestorationforum.com
    email: roger@leatherdoctor.com

  7. #7
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    thank you very much guys for all the information i found here. i had the same stains on my couch and it looks horrible and the only thing i'm looking at (i CAN look at) are those stains and body oil. will try out your methods and see what happens! thanks a lot!

  8. #8
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    Please show some pictures of your progress and we can discuss further . . .

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