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Thread: Leather Care for 1998 BMW M3 Drivers Seat

  1. #1
    Join Date
    Apr 2020
    Posts
    14

    Default Leather Care for 1998 BMW M3 Drivers Seat

    Hello,

    My drivers seat is showing signs of wear so I'm looking for advise on how to proceed.
    The uphostery option is black Nappa leather (N5SW).
    The seat, backrest and headrest are leather and the seat back is plastic.
    There is dye color lost on the left leg bolster and side bolster. For this reason,
    I plan to strip the finish, recondition the leather, re-dye the entire seat and apply
    a matte topcoat followed by a protector.

    My plan is to remove the seat from the car to perform the work. I'll be doing the
    work after-hours at the shop where I work where I will have access to shop air,
    a bench, lots of light and (hopefully) more controlled conditions than I would have at home.

    I've been reading over the info on the site and beginning to get a grasp of the overall steps
    but would like to get your input. Here are some photos of the seats.

    -bruce


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  2. #2
    Join Date
    Apr 2020
    Posts
    14

    Default Steps, Tools and Chemicals

    Here are my proposed steps, chemicals and tools for this refinishing job.

    Leather Refinishing Steps and Chemicals

    1. Strip: Stripper-2.3>Rinse-3.0

    2. Degrease: Degrease-2.2>Acidifier-2.0

    3. Condition: Hydrate-3.3>Fatliquor-5.0

    4. Seal: Adhesor-73

    5. Dye: Micro-54+Thickener-48

    6. Topcoat: MicroTop-54M

    7. Protect: Protector-B


    Leather Refinishing Tools

    brush-1
    brush-2
    brush-9
    eraser-4
    3M grey Scotchbrite (600-800)
    1000/1500/2000 wet dry sandpaper
    microfiber towels
    paper towels
    foam brush
    cling wrap
    airbrush
    heat gun

    For the airbrush, I thinking of getting the Paasche Model H single-action, external mix airbrush
    with 3 heads: .45mm (light fluids), .64mm (medium fluids) and 1.06mm (heavy fluids).
    Most likely I'll be using the 1.06mm head for the dye and topcoat. Thoughts?

  3. #3
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
    Posts
    4,655

    Default

    >>> My drivers seat is showing signs of wear.

    Besides it also is too dry of its original fatliquor (fat and oil content originally average 14%) when dry. So Hydrating-3.3 > Fatliquor-5.0 > Hydrating-3.3 process will replenish it from dry rotting. The hydrating may bring some dyestuff to resurface (if this is a semi-aniline dye through), then after the rejuvenating system, the coloring of the wear areas will look less contrasting (to reduce pigment coating as too thick a pigment coating is more prone to cracking). If the wear also shows signs of weakness from overstretching then the loose structure may be strengthened with Impregnator-26. This leather structure strengthening will reduce the original creases to develop too quickly, on the same location. Restoration and refinishing looking good also have durable performance, otherwise, it is short-lived.

    >>> The seat, backrest and headrest are leather and the seat back is plastic.


    For a good adhesion, Adhesor-73 is scrubbed with a white 3M pad to etch the plastic surface to prime it.

    Name:  rogerIcon.jpg
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    Roger Koh
    Leather, Skin, Hair, Eye & Acne Care System Formulator
    Consultant / Practitioner / Instructor / Coach
    web: www.leatherdoctor.com
    forum: www.leathercleaningrestorationforum.com
    email: [email protected]
    Last edited by Roger Koh; 04-19-2020 at 11:44 AM.

  4. #4
    Join Date
    Apr 2020
    Posts
    14

    Default Updated process

    Thanks Roger, I updated the process per your comments.


    Leather Refinishing Chemicals

    1. Strip: Stripper-2.3>Rinse-3.0

    2. Degrease: Degrease-2.2>Acidifier-2.0

    3. Condition: Hydrate-3.3>Fatliquor-5.0>Hydrate-3.3

    4. Strengthen: Impregnator-26

    5. Prime: Adhesor-73

    6. Dye: Micro-54+Thickener-48

    7. Topcoat: MicroTop-54M

    8. Protect: Protector-B


    Leather Refinishing Tools

    brush-1
    brush-2
    brush-9
    eraser-4
    3M grey Scotchbrite (600-800) #7448
    3M white Scotchbrite (2500) #7445
    1000/1500/2000 wet-or-dry sandpaper
    microfiber towels
    paper towels
    foam brush
    cling wrap
    airbrush
    heat gun

  5. #5
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
    Posts
    4,655

    Default

    >>> Step-1. Strip: Stripper-2.3>Rinse-3.0

    Remember that from the Stripping, Degreasing to the Conditioning process is known as the “WET PROCESS”. It means that the leather throughout these combinations processes has to remain wet at about 25% total moisture.


    >>> Step-2. Degrease: Degrease-2.2 > Acidifier-2.0

    Continue immediately with Step-3


    >>> Step-3. Condition: Hydrate-3.3>Fatliquor-5.0>Hydrate-3.3

    The purpose of the final Hydrator-3.3 application is to rinse off any whitish Fatliquor-5.0 residues, otherwise it may interfere with Refinishing from Step-4 onwards.


    >>> Step-4. Strengthen: Impregnator-26

    Impregnator is meant to impregnate below surface weakness or overstretching especially the creases.


    >>> Step-5. Prime: Adhesor-73

    Adhesor-73 is best etched with a white 3M pad, it also will remove some of deteriorating finishes to micro piles into the leather grain itself for super adhesion from peeling.


    >>> Step-6. Dye: Micro-54+Thickener-48

    A few very lights spray for each coating is recommended than a heavy coating. Of course dry in between coats is highly recommended.


    >>> Step-7. Topcoat: MicroTop-54M

    Matte is 75% dull and may not bring out the beauty of the grain, in fact, matte is used for hiding imperfection or blemishes.


    >>> Step-8. Protect: Protector-B

    I would prefer to have the leather scent on leather, even a blind man would know it is leather or in the dark when picking up your guest - use Protector-B+


    >>> microfiber towels

    Terry Cotton Towel is ideal for wet extraction, microfiber towel is only used on dry surfaces (of course there are many that swear on using microfiber, but my experience on wet extraction does not prove the usefulness on a wet leather surface.)

  6. #6
    Join Date
    Apr 2020
    Posts
    14

    Default

    Thanks Roger for the updates, I will change the microfiber towels to terry cloth and
    change the protector to B+ and change the topcoat to Satin (MicroTop-54S).
    If Satin is too shiny I guess it could be dulled-down. I've read the BMW topcoat
    described as Semi-Matte which sounds like it would be halfway between Satin and Matte.

    I have a question about the dye color. Is the standard black a match for the BMW black Nappa leather?
    This upholstery code is 0522_N5SW_leather, Walknappa/Black.

  7. #7
    Join Date
    Apr 2020
    Posts
    14

    Default Updated process, tools, and chemicals

    Leather Refinishing Chemicals

    1. Strip: Stripper-2.3>Rinse-3.0

    2. Degrease: Degrease-2.2>Acidifier-2.0

    3. Condition: Hydrate-3.3>Fatliquor-5.0>Hydrate-3.3

    4. Strengthen: Impregnator-26

    5. Prime: Adhesor-73

    6. Dye: Micro-54+Thickener-48

    7. Topcoat: MicroTop-54S

    8. Protect: Protector-B+


    Leather Refinishing Tools

    brush-1 (horsehair)
    brush-2 (stiff nylon)
    brush-9 (very stiff nylon)
    foam brush-3
    eraser-4
    paper towels-5
    3M Grey Scotch-Brite (600-800) #7448
    3M White Scotch-Brite (2500) #7445
    3M wet-or-dry sandpaper 1000/1500/2000
    white terry cloth towels
    cling wrap
    airbrush
    air regulator
    heat gun


    Procedure

    1. Stripping

    The purpose of this step is to remove the polyurethane topcoat finish.

    Lightly sand leather surface (avoid seams) with 3M grey Scotch-Brite pad.

    Spray Stripper-2.3 onto leather and agitate with brush-1. Further agitate with brush-2, brush-9 or eraser-4 as necessary.

    Extract suspended finish with terry cloth towel before it dries.

    Spray Rinse-3.0 onto leather and agitate with brush-1.

    Extract suspended soiling with terry cloth towel before it dries.

    Proceed immediately to step 2.


    2. Degreasing

    The purpose of this step is to degrease the leather of penetrated oil, grease and sweat stains from skin and other sources.

    Shake Degreaser-2.2 until it gels. Spray onto leather and saturate to reach penetrated soiling with appropriate brushes and erasers and extract with dry terry cloth towel until towel shows clean.

    Re-apply and allow a dwelling time of 5 to 60 minutes (or before it dries) for a complete soiling suspension to occur and towel extract until it shows clean.

    Spray Acidifier-2.0 to saturate penetrated soiling and use dry terry cotton towel to extract until towel shows clean.

    Proceed immediately to step 3.


    3. Conditioning

    The purpose of this step is to rejuvenate the leather by replenishing the moisture, fat and oils in the leather which will increase the softness, plumpness and strength of the leather.

    Apply Hydrator-3.3 to pre-condition the leather. Use brush-1 to agitate and remove surface soiling. Extract with a terry cloth towel until the towel shows clean.

    Re-apply Hydrator-3.3 with the foam brush and allow it to be absorbed into the leather. Apply paper towels-5 to the leather surface without air gaps
    and saturate with Hydrator-3.3. Apply a cling wrapper over the paper towels to control evaporation. Check dryness of leather and re-apply Hydrator-3.3 often. The leather must be maintained wet.

    The cling wrap can be left on for up to 72hrs to soften up the leather structure. There should be a little moisture oozing out when pressed with fingers and thumb to have the hydration at its optimum level during this dwell time.

    When the leather is limp and soft, the cling wrapper can be removed and soiling is extracted with a terry cloth towel until the towel shows clean.

    While still damp, spray Fatliquor-5.0 onto the leather and spread with the foam brush so as to be fully absorbed by the leather. Re-apply as needed. In each application cycle, 83.33% of the fatliquor water content needs to be evaporated. It is the fat and oil contents that are essential to supple up the leather. The fat plumps the leather and the oil lubricates for softness. When the Fatliquor-5.0 application pools on the surface, this indicates sufficient absorption has occurred.

    Let the leather dry naturally without applied heat. When a surface shine appears, remove it with Hydrator-3.3 until the milky residue is removed from the surface.




    4. Strengthen

    The purpose of this step is to seal, strengthen and level out uneven absorption for the dyeing process. It fills and tightens with good leveling properties that are film-forming to improve abrasion resistance. It is meant to work on below-surface weakness or over-stretching, especially the creases in the leather.

    Shake well and apply Impregnator-26 with brush-1 to saturate all weak, overstretched and highly absorbent damaged areas.

    Concentrate on weak areas. Wipe off unnecessary excess to prevent build-up.

    Sand off surface excess when dry with 1000/2000 grit sandpaper.


    5. Prime

    The purpose of this step is to ensure proper sealing and adhesion of the color dye.

    Shake well, spread evenly with 3M white Scotch-Brite pad (2500) to work into grooves and worn areas. The excess is wiped away with a lint-free towel or until the towel shows clean.

    Let dry naturally or speed dry with a heat gun.


    6. Dye

    The purpose of this step to apply the color dye coat.

    Mix Micro-54 dye and Thickener-48 to stabilize the dye during spraying.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light coat and allow to dry. Accelerate drying with heat gun.
    Apply additional light coats as necessary.


    7. Topcoat

    The purpose of this step is to provide a thin but tough clear polyurethane topcoat to protect against abrasion and wear.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light coat and allow to dry. Accelerate drying with heat gun.
    Apply 2 more light coats.


    8. Protect

    The purpose of this step is to provide a non-stick, rub-resistant protection to the leather and a leather-like scent. This is a sacrificial protection layer and must be replenished periodically.

    Shake well, mist spray and spread with foam brush and it is ready to use when dry.

    During routine application, use a lint-free white towel to pick up soiling at the same time.

  8. #8
    Join Date
    Apr 2020
    Posts
    14

    Default small revisions

    Leather Refinishing Chemicals

    1. Strip: Stripper-2.3>Rinse-3.0

    2. Degrease: Degrease-2.2>Acidifier-2.0

    3. Condition: Hydrate-3.3>Fatliquor-5.0>Hydrate-3.3

    4. Strengthen: Impregnator-26

    5. Prime: Adhesor-73

    6. Dye: Micro-54+Thickener-48

    7. Topcoat: MicroTop-54S

    8. Protect: Protector-B+


    Leather Refinishing Tools

    brush-1 (horsehair)
    brush-2 (stiff nylon)
    brush-9 (very stiff nylon)
    foam brush-3
    eraser-4
    paper towels-5
    3M Grey Scotch-Brite (600-800) #7448
    3M White Scotch-Brite (2500) #7445
    3M wet-or-dry sandpaper 1000/1500/2000
    white terry cloth towels
    cling wrap
    airbrush
    air regulator
    heat gun


    Procedure

    1. Stripping

    The purpose of this step is to remove the clear polyurethane topcoat finish.

    Lightly sand leather surface (avoid seams) with 3M grey Scotch-Brite pad.

    Spray Stripper-2.3 onto leather and agitate with brush-1. Further agitate with brush-2, brush-9 or eraser-4 as necessary.

    Extract suspended finish with terry cloth towel before it dries.

    Spray Rinse-3.0 onto leather and agitate with brush-1.

    Extract suspended soiling with terry cloth towel before it dries.

    Proceed immediately to step 2.


    2. Degreasing

    The purpose of this step is to degrease the leather of penetrated oil, grease and sweat stains from skin and other sources.

    Shake Degreaser-2.2 until it gels. Spray onto leather and saturate to reach penetrated soiling with appropriate brushes and erasers and extract with dry terry cloth towel until towel shows clean.

    Re-apply and allow a dwelling time of 5 to 60 minutes (or before it dries) for a complete soiling suspension to occur and towel extract until it shows clean.

    Spray Acidifier-2.0 to saturate penetrated soiling and use dry terry cotton towel to extract until towel shows clean.

    Proceed immediately to step 3.


    3. Conditioning

    The purpose of this step is to rejuvenate the leather by replenishing the moisture, fat and oils in the leather which will increase the softness, plumpness and strength of the leather.

    Apply Hydrator-3.3 to pre-condition the leather. Use brush-1 to agitate and remove surface soiling. Extract with a terry cloth towel until the towel shows clean.

    Re-apply Hydrator-3.3 with the foam brush and allow it to be absorbed into the leather. Apply paper towels-5 to the leather surface without air gaps
    and saturate with Hydrator-3.3. Apply a cling wrapper over the paper towels to control evaporation. Check dryness of leather and re-apply Hydrator-3.3 often. The leather must be maintained wet.

    The cling wrap can be left on for up to 72hrs to soften up the leather structure. There should be a little moisture oozing out when pressed with fingers and thumb to have the hydration at its optimum level during this dwell time.

    When the leather is limp and soft, the cling wrapper can be removed and soiling is extracted with a terry cloth towel until the towel shows clean.

    While still damp, spray Fatliquor-5.0 onto the leather and spread with the foam brush so as to be fully absorbed by the leather. Re-apply as needed. In each application cycle, 83.33% of the fatliquor water content needs to be evaporated. It is the fat and oil contents that are essential to supple up the leather. The fat plumps the leather and the oil lubricates for softness. When the Fatliquor-5.0 application pools on the surface, this indicates sufficient absorption has occurred.

    Let the leather dry naturally without applied heat. When a surface shine appears, remove it with Hydrator-3.3 until the milky residue is removed from the surface.


    4. Strengthen

    The purpose of this step is to seal, strengthen and level out uneven absorption for the dyeing process. It fills and tightens with good leveling properties that are film-forming to improve abrasion resistance. It is meant to work on below-surface weakness or over-stretching, especially the creases in the leather.

    Shake well and apply Impregnator-26 with brush-1 to saturate all weak, overstretched and highly absorbent damaged areas.

    Concentrate on weak areas. Wipe off unnecessary excess to prevent build-up.

    Sand off surface excess when dry with 1000/2000 grit sandpaper.


    5. Prime

    The purpose of this step is to ensure proper sealing and adhesion of the color dye.

    Shake well, spread Adhesor-73 evenly with a 3M white Scotch-Brite pad (2500) to work into grooves and worn areas. Wipe away the excess with a white terry cloth towel.

    Let dry naturally or speed dry with a heat gun.


    6. Dye

    The purpose of this step to apply the color dye coat.

    Mix Micro-54 dye and Thickener-48 to stabilize the dye during spraying.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light coat of dye and allow to dry. Accelerate drying with heat gun.
    Apply additional light coats as necessary.


    7. Topcoat

    The purpose of this step is to provide a thin but tough clear polyurethane topcoat to protect against abrasion and wear.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light coat of MicroTop-54S and allow to dry. Accelerate drying with heat gun.
    Apply 2 more light coats.


    8. Protect

    The purpose of this step is to provide a non-stick, rub-resistant protection to the leather and a leather-like scent.

    Shake well, spray Protector-B+ onto the leather and spread with foam brush. It is ready to use when dry.

    This is a sacrificial protection layer and must be replenished periodically.
    Re-apply every coupe of months or as necessary.

  9. #9
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
    Posts
    4,655

    Default

    Tips:

    The Degreasing Step should come before the Stripping Step. You would understand when you do according to my recommendation.

    >>> Lightly sand leather surface (avoid seams) with 3M grey Scotch-Brite pad.

    Avoid sanding the leather grains, only the finishes.


    >>> Spray Stripper-2.3 onto leather and agitate with brush-1. Further agitate with brush-2, brush-9 or eraser-4 as necessary.

    Again, it is the leather finishes that need stripping, so avoid spraying onto leather grains as Stripper-2.3 does dry up its original fatliquor (fat and oil) too.

    Degreasing > Stripping > Conditioning is the “wet process” of leather cleaning and restoration, and should be kept at about 25% total moisture content in between processes, slow drying at the last process will produce a more supple leather, so do not use any heat drying process.


    >>> The purpose of this step is to seal, strengthen, and level out uneven absorption for the dyeing process.

    Note, that this is a pigment opaque coloring process and no transparent dyestuff is involved.


    >>> Sand off surface excess when dry with 1000/2000 grit sandpaper.

    Use Hydrator-3.3 to wipe surface residue to avoid the use of the sandpaper.


    >>> 6. Dye

    It is Micro-Pigment Color Coating, a dye is transparent, the pigment is opaque with good coverage.

  10. #10
    Join Date
    Apr 2020
    Posts
    14

    Default Updated pre feedback

    BMW Black Nappa Leather Seat Refinishing

    BMW Nappa leather is a full-grain leather, which means the surface has not been removed or altered. Accordingly it retains a lot of the original textures and markings of the hide. This semi-aniline leather has a finisher applied to it for durability as well as more pigmentation than aniline products. Despite these enhancements it still retains a natural look since it’s the original grain surface of the skin that’s not been altered beyond the hair being removed.

    When refinishing BMW Nappa leather, care must be taken to not diminish the grain surface. This applies especially to the use of abrasives during cleaning and preparation steps.

    Leather Doctor Refinishing Chemicals

    1. Degrease: Degrease-2.2>Acidifier-2.0

    2. Strip: Stripper-2.3>Rinse-3.0

    3. Condition: Hydrate-3.3>Fatliquor-5.0>Hydrate-3.3

    4. Strengthen: Impregnator-26

    5. Prime: Adhesor-73

    6. Color Coat: Micro-54 + Thickener-48

    7. Topcoat: MicroTop-54S

    8. Protect: Protector-B+


    Leather Doctor Refinishing Tools

    brush-1 (horsehair)
    brush-2 (stiff nylon)
    brush-9 (very stiff nylon)
    foam brush-3
    eraser-4
    paper towels-5

    Other Tools

    3M Grey Scotch-Brite pad (600-800) #7448
    3M White Scotch-Brite pad (2500) #7445
    3M wet-or-dry sandpaper 1000/1500/2000
    white terry cloth towels
    cling wrap
    airbrush
    air regulator
    heat gun


    Procedure


    1. Degreasing

    The purpose of this step is to degrease the leather of penetrated oil, grease and sweat stains from skin, food, drink and other sources.

    Shake Degreaser-2.2 until it gels. Spray onto seat surface and saturate to reach penetrated soiling with appropriate brushes and erasers and extract with dry terry cloth towel until towel shows clean.

    Re-apply and allow a dwelling time of 5 to 60 minutes (or before it dries) for a complete soiling suspension to occur and towel extract until it shows clean.

    Spray Acidifier-2.0 to saturate penetrated soiling and use dry terry cotton towel to extract until towel shows clean.

    Proceed immediately to step 2 to keep the moisture content up.


    2. Stripping

    The purpose of this step is to remove the clear polyurethane topcoat finish.

    Lightly sand clear topcoat finish (avoid raised seams) with 3M grey Scotch-Brite pad. Avoid sanding the leather grain, sand only the clear topcoat finish.

    Spray Stripper-2.3 onto clear topcoat finish and agitate with brush-1. Further agitate with brush-2, brush-9 or eraser-4 as necessary. Avoid spraying onto leather grains as Stripper-2.3 does dry up the leather fatliquor (fat and oil) too.

    Extract suspended finish with terry cloth towel before it dries.

    Spray Rinse-3.0 onto leather and agitate with brush-1.

    Extract suspended soiling with terry cloth towel before it dries.

    Proceed immediately to step 2 to keep the moisture content up.


    3. Conditioning

    The purpose of this step is to rejuvenate the leather by replenishing the moisture, fat and oils in the leather which will increase the softness, plumpness and strength of the leather.

    Apply Hydrator-3.3 to pre-condition the leather. Use brush-1 to agitate and remove surface soiling. Extract with a terry cloth towel until the towel shows clean.

    Re-apply Hydrator-3.3 with the foam brush and allow it to be absorbed into the leather. Apply paper towels-5 to the leather surface without air gaps and saturate with Hydrator-3.3. Apply a cling wrapper over the paper towels to control evaporation. Check dryness of leather and re-apply Hydrator-3.3 often. The leather must be maintained wet.

    The cling wrap can be left on for up to 72hrs to soften up the leather structure. There should be a little moisture oozing out when pressed with fingers and thumb to have the hydration at its optimum level during this dwell time.

    When the leather is limp and soft, the cling wrapper can be removed and soiling is extracted with a terry cloth towel until the towel shows clean.

    While still damp, spray Fatliquor-5.0 onto the leather and spread with the foam brush so as to be fully absorbed by the leather. Re-apply as needed. In each application cycle, 83.33% of the fatliquor water content needs to be evaporated. It is the fat and oil contents that are essential to supple up the leather. The fat plumps the leather and the oil lubricates for softness. When the Fatliquor-5.0 application pools on the surface, this indicates sufficient absorption has occurred.

    Let the leather dry naturally without applied heat. When a surface shine appears, remove it with Hydrator-3.3 until the milky residue is removed from the surface.


    4. Strengthen

    The purpose of this step is to seal, strengthen and level out uneven absorption for the color coat process. It fills and tightens with good leveling properties that are film-forming to improve abrasion resistance. It is meant to work on below-surface weakness or over-stretching, especially the creases in the leather.

    Shake well and apply Impregnator-26 with brush-1 to saturate all weak, overstretched and highly absorbent damaged areas.

    Concentrate on weak areas. Wipe off unnecessary excess to prevent build-up.

    Use Hydrator-3.3 to wipe surface residue to avoid the use of the sandpaper.


    5. Prime

    The purpose of this step is to ensure proper sealing and adhesion of the color coat.

    Shake well, spread Adhesor-73 evenly with a 3M white Scotch-Brite pad (2500) to work into grooves and worn areas. Wipe away the excess with a white terry cloth towel.

    Let dry naturally or speed dry with a heat gun.


    6. Color coat

    The purpose of this step to apply the color coat. Micro-54 is designed for micro pigmented leathers also known as semi-aniline. This is a water-based compact resin blend high performance UV fade resistant pigment color coat.

    Mix Micro-54 and Thickener-48 to stabilize the color coat during spraying.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light color coat and allow to dry. Accelerate drying with heat gun. Apply additional light coats as necessary.


    7. Topcoat

    The purpose of this step is to provide a thin but tough clear polyurethane topcoat to protect against abrasion and wear. MicroTop-54 is the matching sealing topcoat in this pigment series system.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light coat of MicroTop-54S and allow to dry. Accelerate drying with heat gun. Apply 2 more light coats.


    8. Protect

    The purpose of this step is to provide a non-stick, rub-resistant protection to the leather and a leather-like scent.

    Shake well, spray Protector-B+ onto the leather and spread with foam brush. It is ready to use when dry.

    This is a sacrificial protection layer and must be replenished periodically. Re-apply every coupe of months or as necessary.

  11. #11
    Join Date
    Apr 2020
    Posts
    14

    Default Updated with revisions to color coat and topcoat

    BMW Black Nappa Leather Seat Refinishing

    BMW Nappa leather is a full-grain leather, which means the surface has not been removed or altered. Accordingly it retains a lot of the original textures and markings of the hide. This semi-aniline leather has a finisher applied to it for durability as well as more pigmentation than aniline products. Despite these enhancements it still retains a natural look since its the original grain surface of the skin thats not been altered beyond the hair being removed.

    When refinishing BMW Nappa leather, care must be taken to not diminish the grain surface. This applies especially to the use of abrasives during cleaning and preparation steps.

    BMW Nappa Leather is made for BMW by the German company Bader Leather.


    Leather Doctor Refinishing Chemicals

    1. Degrease: Degrease-2.2>Acidifier-2.0

    2. Strip: Stripper-2.3>Rinse-3.0

    3. Condition: Hydrate-3.3>Fatliquor-5.0>Hydrate-3.3

    4. Strengthen: Impregnator-26

    5. Prime: Adhesor-73

    6. Color Coat: Micro-54 + Thickener-48

    7. Topcoat: MicroTop-54G + Duller-63

    8. Protect: Protector-B+


    Leather Doctor Refinishing Tools

    brush-1 (horsehair)
    brush-2 (stiff nylon)
    brush-9 (very stiff nylon)
    foam brush-3
    eraser-4
    paper towels-5

    Other Tools

    3M Grey Scotch-Brite pad (600-800) #7448
    3M White Scotch-Brite pad (2500) #7445
    3M wet-or-dry sandpaper 1000/1500/2000
    white terry cloth towels
    cling wrap
    sponge applicator
    airbrush
    air compressor
    air regulator
    mask or respirator
    heat gun


    Procedure


    1. Degreasing

    The purpose of this step is to degrease the leather of penetrated oil, grease and sweat stains from skin, food, drink and other sources.

    Shake Degreaser-2.2 until it gels. Spray onto seat surface and saturate to reach penetrated soiling with appropriate brushes and erasers and extract with dry terry cloth towel until towel shows clean.

    Re-apply and allow a dwelling time of 5 to 60 minutes (or before it dries) for a complete soiling suspension to occur and towel extract until it shows clean.

    Spray Acidifier-2.0 to saturate penetrated soiling and use dry terry cotton towel to extract until towel shows clean.

    Proceed immediately to step 2 to keep the moisture content up.


    2. Stripping

    The purpose of this step is to remove the clear polyurethane topcoat finish.

    Lightly sand clear topcoat finish (avoid raised seams) with 3M grey Scotch-Brite pad. Avoid sanding the leather grain, sand only the clear topcoat finish.

    Spray Stripper-2.3 onto clear topcoat finish and agitate with brush-1. Further agitate with brush-2, brush-9 or eraser-4 as necessary. Avoid spraying onto leather grains as Stripper-2.3 does dry up the leather fatliquor (fat and oil) too.

    Extract suspended finish with terry cloth towel before it dries.

    Spray Rinse-3.0 onto leather and agitate with brush-1.

    Extract suspended soiling with terry cloth towel before it dries.

    Proceed immediately to step 2 to keep the moisture content up.


    3. Conditioning

    The purpose of this step is to rejuvenate the leather by replenishing the moisture, fat and oils in the leather which will increase the softness, plumpness and strength of the leather.

    Apply Hydrator-3.3 to pre-condition the leather. Use brush-1 to agitate and remove surface soiling. Extract with a terry cloth towel until the towel shows clean.

    Re-apply Hydrator-3.3 with the foam brush and allow it to be absorbed into the leather. Apply paper towels-5 to the leather surface without air gaps and saturate with Hydrator-3.3. Apply a cling wrapper over the paper towels to control evaporation. Check dryness of leather and re-apply Hydrator-3.3 often. The leather must be maintained wet.

    The cling wrap can be left on for up to 72hrs to soften up the leather structure. There should be a little moisture oozing out when pressed with fingers and thumb to have the hydration at its optimum level during this dwell time.

    When the leather is limp and soft, the cling wrapper can be removed and soiling is extracted with a terry cloth towel until the towel shows clean.

    While still damp, spray Fatliquor-5.0 onto the leather and spread with the foam brush so as to be fully absorbed by the leather. Re-apply as needed. In each application cycle, 83.33% of the fatliquor water content needs to be evaporated. It is the fat and oil contents that are essential to supple up the leather. The fat plumps the leather and the oil lubricates for softness. When the Fatliquor-5.0 application pools on the surface, this indicates sufficient absorption has occurred.

    Let the leather dry naturally without applied heat. When a surface shine appears, remove it with Hydrator-3.3 until the milky residue is removed from the surface.


    4. Strengthen

    The purpose of this step is to seal, strengthen and level out uneven absorption for the color coat process. It fills and tightens with good leveling properties that are film-forming to improve abrasion resistance. It is meant to work on below-surface weakness or over-stretching, especially the creases in the leather.

    Shake well and apply Impregnator-26 with brush-1 to saturate all weak, overstretched and highly absorbent damaged areas.

    Concentrate on weak areas. Wipe off unnecessary excess to prevent build-up.

    Use Hydrator-3.3 to wipe surface residue to avoid the use of the sandpaper.


    5. Prime

    The purpose of this step is to ensure proper sealing and adhesion of the color coat.

    Shake well, spread Adhesor-73 evenly with a 3M white Scotch-Brite pad (2500) to work into grooves and worn areas. Wipe away the excess with a white terry cloth towel.

    Let dry naturally or speed dry with a heat gun.


    6. Color coat

    The purpose of this step to apply the color coat. Micro-54 is designed for micro pigmented leathers also known as semi-aniline. This is a water-based pigment color coat.

    The first coat is applied by sponge. This is done to work the color into hard to reach areas and to also minimise later spray applications. Dab the sponge onto the leather and avoid creating streaks.

    The next step is to spray the leather color onto the leather using the airbrush to produce a uniform and professional appearance.

    Mix Micro-54 and Thickener-48 to stabilize the color coat during spraying.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Working with one seat panel at a time, first spray the seams and around the edges. Then proceed to spray on thin coats, overlaping 50%, until it looks nice and uniform.

    Allow each coat to dry before spraying the next. Accelerate drying with heat gun.


    7. Topcoat

    The purpose of this step is to provide a thin but tough clear polyurethane topcoat to protect against abrasion and wear. MicroTop-54 is the matching sealing topcoat in this pigment series system. Duller-63 is used to adjust the surface sheen. BMW Nappa Leather should have a semi-matte appearance.

    To adjust the surface sheen for semi-matte, mix MicroTop-54G (Gloss) with Duller-63 by adding approximately 35% Duller-63.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light coat and allow to dry. Accelerate drying with heat gun. Apply 2 more light coats or as needed.


    8. Protect

    The purpose of this step is to provide a non-stick, rub-resistant protection to the leather and a leather-like scent.

    Shake well, spray Protector-B+ onto the leather and spread with foam brush. It is ready to use when dry.

    This is a sacrificial protection layer and must be replenished periodically. Re-apply every couple of months or as necessary.

  12. #12
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
    Posts
    4,655

    Default

    Bruce,

    Here is the revised version for your consideration . . .

    BMW Black Nappa Leather Seat Refinishing

    BMW Nappa leather is top-grain leather, which retains a lot of the original textures and markings of the hide. This semi-aniline leather is first dyed through with transparent dyestuff so that the suede side takes the same color shade as the grain side. A fine opaque micro-pigment is then applied to the grain side to camouflage blemishes or imperfection for a mono-tone appearance. We can consider its finish as half transparent aniline-dyed grains and half opaque micro-pigment sprayed on for a more even appearance, thus befits its name as semi-aniline.

    The advantage of restoration and refinishing a semi-aniline over pigmented leather is that the excess dyestuff within the leather structure can be hydrated to resurface to reduce the contrast in appearance between worn, sun-faded, creases and micro-cracks from surrounding areas prior to reduced micro-pigment coatings. Diminishing original average 14% fatliquor (fat and oil) content from aging lightens the color saturation and is replenishable to increase the color saturation. These hydrating and fatliquoring capabilities rejuvenate the leather structure both in appearance and suppleness. When worn, creases, and micro-cracks appearances are less contrasting, less micro-pigment is used. In contrast, more coatings mean producing a lower grade leather. Micro-pigment is a finer and higher quality pigment that is also strong against sunlight fading. This micro-pigment is adjusted with an auxiliary thickener to control flow during fine airbrushing. In a three dimensional airbrushing, a cone shape pattern spray produces better results due to ease of directional control. An artistic technique produces a professional result, and a few light coats with in-between drying produces better results than heavy coatings. The objective is to retain its natural appearance with suppleness for seating comfort and a good feel of hand.

    When refinishing BMW Nappa leather, care must be taken not to diminish the grain surface. This applies especially to the use of abrasives during cleaning and preparation steps. Sanding is only performed on the coatings or finishes, sanding to the grains is to be avoided as the coarseness of the grain increases with reduced tensile strength.

    BMW Nappa Leather is made for BMW by the German company Bader Leather.

    . . . to continue.

  13. #13
    Join Date
    Apr 2020
    Posts
    14

    Default

    Quote Originally Posted by Roger Koh View Post
    Bruce,

    Here is the revised version for your consideration . . .

    BMW Black Nappa Leather Seat Refinishing

    BMW Nappa leather is top-grain leather, which retains a lot of the original textures and markings of the hide. This semi-aniline leather is first dyed through with transparent dyestuff so that the suede side takes the same color shade as the grain side. A fine opaque micro-pigment is then applied to the grain side to camouflage blemishes or imperfection for a mono-tone appearance. We can consider its finish as half transparent aniline-dyed grains and half opaque micro-pigment sprayed on for a more even appearance, thus befits its name as semi-aniline.

    The advantage of restoration and refinishing a semi-aniline over pigmented leather is that the excess dyestuff within the leather structure can be hydrated to resurface to reduce the contrast in appearance between worn, sun-faded, creases and micro-cracks from surrounding areas prior to reduced micro-pigment coatings. Diminishing original average 14% fatliquor (fat and oil) content from aging lightens the color saturation and is replenishable to increase the color saturation. These hydrating and fatliquoring capabilities rejuvenate the leather structure both in appearance and suppleness. When worn, creases, and micro-cracks appearances are less contrasting, less micro-pigment is used. In contrast, more coatings mean producing a lower grade leather. Micro-pigment is a finer and higher quality pigment that is also strong against sunlight fading. This micro-pigment is adjusted with an auxiliary thickener to control flow during fine airbrushing. In a three dimensional airbrushing, a cone shape pattern spray produces better results due to ease of directional control. An artistic technique produces a professional result, and a few light coats with in-between drying produces better results than heavy coatings. The objective is to retain its natural appearance with suppleness for seating comfort and a good feel of hand.

    When refinishing BMW Nappa leather, care must be taken not to diminish the grain surface. This applies especially to the use of abrasives during cleaning and preparation steps. Sanding is only performed on the coatings or finishes, sanding to the grains is to be avoided as the coarseness of the grain increases with reduced tensile strength.

    BMW Nappa Leather is made for BMW by the German company Bader Leather.

    . . . to continue.
    Thank you Roger for the added technical detail. I will incorporate this into the whole posting but first I want to ask you about the color coating process.
    In light of what you have just said about the ability to restore the color coat during rejuvenation, perhaps in the case of this seat all I may need to do is
    apply a new color coat only to the leg and side bolsters. Assuming we can get a good color match to blend in with the rest of the seat, it would save a lot of
    effort in stripping and re-coating the other parts of the seat. Does that sound possible or too good to be true?

    Also, are you ok with the idea of applying the first color coat by sponge dabbing or do you think I should use the airbrush exclusively?

    -bruce

  14. #14
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
    Posts
    4,655

    Default

    >>> In light of what you have just said about the ability to restore the color coat during rejuvenation,

    No, we cannot restore the “color coat”, we only can activate the excess aniline dyestuff within the leather structure, to resurface. Test a spot to determine the success rate with Hydrator-3.3 for satisfaction.


    >>> perhaps in the case of this seat all I may need to do is apply a new color coat only to the leg and side bolsters. Assuming we can get a good color match to blend in with the rest of the seat, it would save a lot of effort in stripping and re-coating the other parts of the seat. Does that sound possible or too good to be true?

    There is no need to strip the rest of the good areas down to the leather grain. Just sand off the topcoat will do. The entire leather will all need a color coating, it is how much to strip and how much to coat back. To even out wear and final appearance. So it is seldom a 100% strip down and builds up job.

    >>> Also, are you ok with the idea of applying the first color coat by sponge dabbing or do you think I should use the airbrush exclusively?


    The primer coating is scrub with 3M white nylon, it will take off some deteriorating finishes too. The first color coating is also preferably etched into the primer coating for better bonding. Then begins the second coating with fine spraying without excess flow. Flow is excess spraying, either control with Thickener-48 or balance of more air and less feed.

  15. #15
    Join Date
    Apr 2020
    Posts
    14

    Default Updates from comments

    BMW Black Nappa Leather Seat Refinishing

    BMW Nappa leather is top-grain leather, which retains a lot of the original textures and markings of the hide. This semi-aniline leather is first dyed through with transparent dyestuff so that the suede side takes the same color shade as the grain side. A fine opaque micro-pigment is then applied to the grain side to camouflage blemishes or imperfection for a mono-tone appearance. We can consider its finish as half transparent aniline-dyed grains and half opaque micro-pigment sprayed on for a more even appearance, thus befits its name as semi-aniline.

    The advantage of restoration and refinishing a semi-aniline over pigmented leather is that the excess dyestuff within the leather structure can be hydrated to resurface to reduce the contrast in appearance between worn, sun-faded, creases and micro-cracks from surrounding areas prior to reduced micro-pigment coatings. Diminishing original average 14% fatliquor (fat and oil) content from aging lightens the color saturation and is replenishable to increase the color saturation. These hydrating and fatliquoring capabilities rejuvenate the leather structure both in appearance and suppleness. When worn, creases, and micro-cracks appearances are less contrasting, less micro-pigment is used. In contrast, more coatings mean producing a lower grade leather. Micro-pigment is a finer and higher quality pigment that is also strong against sunlight fading. This micro-pigment is adjusted with an auxiliary thickener to control flow during fine airbrushing. In a three dimensional airbrushing, a cone shape pattern spray produces better results due to ease of directional control. An artistic technique produces a professional result, and a few light coats with in-between drying produces better results than heavy coatings. The objective is to retain its natural appearance with suppleness for seating comfort and a good feel of hand.

    When refinishing BMW Nappa leather, care must be taken not to diminish the grain surface. This applies especially to the use of abrasives during cleaning and preparation steps. Sanding is only performed on the coatings or finishes, sanding to the grains is to be avoided as the coarseness of the grain increases with reduced tensile strength.

    BMW Nappa Leather is made for BMW by the German company Bader Leather.

    Leather Doctor Refinishing Chemicals

    1. Degrease: Degrease-2.2>Acidifier-2.0

    2. Strip: Stripper-2.3>Rinse-3.0

    3. Condition: Hydrate-3.3>Fatliquor-5.0>Hydrate-3.3

    4. Strengthen: Impregnator-26

    5. Prime: Adhesor-73

    6. Color Coat: Micro-54 + Thickener-48

    7. Topcoat: MicroTop-54G + Duller-63

    8. Protect: Protector-B+


    Leather Doctor Refinishing Tools

    brush-1 (horsehair)
    brush-2 (stiff nylon)
    brush-9 (very stiff nylon)
    foam brush-3
    eraser-4
    paper towels-5

    Other Tools

    3M Grey Scotch-Brite pad (600-800) #7448
    3M White Scotch-Brite pad (2500) #7445
    3M wet-or-dry sandpaper 1000/1500/2000
    white terry cloth towels
    cling wrap
    airbrush
    air compressor
    air regulator
    mask or respirator
    heat gun


    Procedure


    1. Degreasing

    The purpose of this step is to degrease the leather of penetrated oil, grease and sweat stains from skin, food, drink and other sources.

    Shake Degreaser-2.2 until it gels. Spray onto seat surface and saturate to reach penetrated soiling with appropriate brushes and erasers and extract with dry terry cloth towel until towel shows clean.

    Re-apply and allow a dwelling time of 5 to 60 minutes (or before it dries) for a complete soiling suspension to occur and towel extract until it shows clean.

    Spray Acidifier-2.0 to saturate penetrated soiling and use dry terry cotton towel to extract until towel shows clean.

    Proceed immediately to step 2 to keep the moisture content up.


    2. Stripping

    The purpose of this step is to remove the clear polyurethane topcoat finish.

    Note: For very worn areas such as side and leg bolsters, strip the color coat as well.

    Lightly sand clear topcoat finish (avoid raised seams) with 3M grey Scotch-Brite pad. Avoid sanding the leather grain, sand only the clear topcoat finish until a white residue appears.

    Spray Stripper-2.3 onto clear topcoat finish and agitate with brush-1. Further agitate with brush-2, brush-9 or eraser-4 as necessary. Avoid spraying onto leather grains as Stripper-2.3 does dry up the leather fatliquor (fat and oil) too.

    Extract suspended finish with terry cloth towel before it dries.

    Spray Rinse-3.0 onto leather and agitate with brush-1.

    Extract suspended soiling with terry cloth towel before it dries.

    Proceed immediately to step 2 to keep the moisture content up.


    3. Conditioning

    The purpose of this step is to rejuvenate the leather by replenishing the moisture, fat and oils in the leather which will increase the softness, plumpness and strength of the leather.

    Apply Hydrator-3.3 to pre-condition the leather. Use brush-1 to agitate and remove surface soiling. Extract with a terry cloth towel until the towel shows clean.

    Re-apply Hydrator-3.3 with the foam brush and allow it to be absorbed into the leather. Apply paper towels-5 to the leather surface without air gaps and saturate with Hydrator-3.3. Apply a cling wrapper over the paper towels to control evaporation. Check dryness of leather and re-apply Hydrator-3.3 often. The leather must be maintained wet.

    The cling wrap can be left on for up to 72hrs to soften up the leather structure. There should be a little moisture oozing out when pressed with fingers and thumb to have the hydration at its optimum level during this dwell time.

    When the leather is limp and soft, the cling wrapper can be removed and soiling is extracted with a terry cloth towel until the towel shows clean.

    While still damp, spray Fatliquor-5.0 onto the leather and spread with the foam brush so as to be fully absorbed by the leather. Re-apply as needed. In each application cycle, 83.33% of the fatliquor water content needs to be evaporated. It is the fat and oil contents that are essential to supple up the leather. The fat plumps the leather and the oil lubricates for softness. When the Fatliquor-5.0 application pools on the surface, this indicates sufficient absorption has occurred.

    Let the leather dry naturally without applied heat. When a surface shine appears, remove it with Hydrator-3.3 until the milky residue is removed from the surface.




    4. Strengthen

    The purpose of this step is to seal, strengthen and level out uneven absorption for the color coat process. It fills and tightens with good leveling properties that are film-forming to improve abrasion resistance. It is meant to work on below-surface weakness or over-stretching, especially the creases in the leather.

    Shake well and apply Impregnator-26 with brush-1 to saturate all weak, overstretched and highly absorbent damaged areas.

    Concentrate on weak areas. Wipe off unnecessary excess to prevent build-up.

    Use Hydrator-3.3 to wipe surface residue to avoid the use of the sandpaper.


    5. Prime

    The purpose of this step is to ensure proper sealing and adhesion of the color coat.

    Shake well, spread Adhesor-73 evenly with a 3M white Scotch-Brite pad (2500) to work into grooves and worn areas. Wipe away the excess with a white terry cloth towel.

    Let dry naturally or speed dry with a heat gun.


    6. Color coat

    The purpose of this step to apply the color coat. Micro-54 is designed for micro pigmented leathers also known as semi-aniline. This is a water-based pigment color coat.

    The first coat is applied by 3M white Scotch-Brite pad. This will etch the color coat into the primer coating for better bonding and to also minimise later spray applications.

    The next step is to spray additional fine leather color coats onto the leather using the airbrush to produce a uniform and professional appearance.

    Mix Micro-54 and Thickener-48 to stabilize the color coat during spraying.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Working with one seat panel at a time, first spray the seams and around the edges. Then proceed to spray on thin coats, overlaping 50%, until it looks nice and uniform.

    Allow each coat to dry before spraying the next. Accelerate drying with heat gun.


    7. Topcoat

    The purpose of this step is to provide a thin but tough clear polyurethane topcoat to protect against abrasion and wear. MicroTop-54 is the matching sealing topcoat in this pigment series system. Duller-63 is used to adjust the surface sheen. BMW Nappa Leather should have a semi-matte appearance.

    To adjust the surface sheen for semi-matte, mix MicroTop-54G (Gloss) with Duller-63 by adding approximately 35% Duller-63.

    Setup airbrush for spraying and adjust air pressure for proper pattern.

    Apply a light coat and allow to dry. Accelerate drying with heat gun. Apply 2 more light coats or as needed.


    8. Protect

    The purpose of this step is to provide a non-stick, rub-resistant protection to the leather and a leather-like scent.

    Shake well, spray Protector-B+ onto the leather and spread with foam brush. It is ready to use when dry.

    This is a sacrificial protection layer and must be replenished periodically. Re-apply every couple of months or as necessary.

  16. #16
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
    Posts
    4,655

    Default

    This is an edited version, and to be refined accordingly as necessary to further clarify that fits the actual real-life review.

    BMW Black Nappa Leather Seat Refinishing:

    BMW Nappa leather is full-grain leather, which means the surface has not been removed or altered. Accordingly, it retains a lot of the original textures and markings of the hide. This semi-aniline leather has a finisher applied to it for durability as well as more pigmentation than aniline products. Despite these enhancements, it still retains a natural look since it’s the original grain surface of the skin that’s not been altered beyond the hair being removed. When refinishing BMW Nappa leather, care must be taken to not diminish the grain surface. This applies especially to the use of abrasives during cleaning and preparation steps. BMW Nappa Leather is made for BMW by the German company Bader Leather.


    Cleaning and Conditioning based on Modern Tannery Scientific Principles:

    The neutral pH value of leather is on the acidic side of the pH scale between 3 and 5. Keeping in mind that after cleaning and conditioning the leather structure should return to its original neutral pH value. This neutral pH environment stabilizes the leather constituents of the tanning agent, dyestuff and fatliquor to its original chemistry integrity. Thus selecting a range of leather-safe products is vital to its effective and safe cleaning and conditioning processes.


    Leather Doctor Cleaning and Restoration Products:

    The suffix number of each cleaning and conditioning product represents its pH value. Thus Degreaser-2.2 has a pH value of 2.2.

    1. Degreaser: Degrease-2.2 > Acidifier-2.0

    2. Stripper: Stripper-2.3 > Rinse-3.0

    3. Conditioner: Hydrate-3.3 > Fatliquor-5.0 > Hydrate-3.3

    4. Strengthener: Impregnator-26

    5. Primer: Adhesor-73

    6. Color Coat: Micro-54 + Thickener-48

    7. Top Coat: MicroTop-54G + Duller-63

    8. Protector: Protector-B+


    Leather Doctor Refinishing Tools:

    Brush-1 (horsehair)

    Brush-2 (stiff nylon)

    Brush-9 (very stiff nylon)

    Foam brush-3

    Leather eraser-4

    Paper towels-5


    Other Tools:

    Wet/Dry Sandpaper 1000, 1500, 2000 grits.

    3M Grey Scotch-Brite pad (600-800) #7448

    3M White Scotch-Brite pad (2500) #7445

    3M wet-or-dry sandpaper 1000/1500/2000

    White terry cloth towels

    Cling wrap

    Foam Brush

    Airbrush

    Air compressor

    Air regulator

    Mask or Respirator

    Hair Dryer

    Oscillator Sander


    Procedure:

    1. Degreasing of Surface Oil, Grease and Sweat:

    1-A. The purpose of this Degreasing step-1 is to degrease the leather of penetrated oil, grease, and sweat stains from skin, food, drink, and other sources.

    1-B. Shake Degreaser-2.2 until it gels. Apply onto the seat surface and saturate to reach penetrated soiling with appropriate soft horsehair brushes and leather eraser and extract with dry terry cloth towel until towel shows clean.

    1-C. Re-apply and allow a dwelling time of 5 to 60 minutes (or before it dries) for a complete soiling suspension to occur, brush and scrub with a leather eraser and towel extract until it shows clean.

    1-D. Spray Acidifier-2.0 to saturate penetrated soiling and use dry terry cotton towel to extract until the towel shows clean.

    1-E. Towel extract surface dry without drying out the moisture level of the structure and proceed immediately to Stripping step-2 for a more effective working power of Stripper-2.3.


    2. Stripping Deteriorating Finishes:

    2-A. The purpose of this step is to remove the clear polyurethane topcoat finish.

    2-B.Lightly sand clear topcoat finish (avoid raised seams) with 1000, 1500 & 2000grit wet sandpaper. Avoid sanding the leather grain, sand only the clear top coat finish until a white residue disappears.

    2-C.Spray Stripper-2.3 onto clear topcoat finish and agitate with brush-1. Further agitate with brush-2, brush-9 or eraser-4 as necessary in conjunction with 1000, 1500 & 200grit to smooth the surface testing with fingertips. Avoid spraying onto leather grains as Stripper-2.3 does dry up the leather fatliquor (fat and oil) too.

    2-D. Extract suspended finish with a terry cloth towel before it dries.

    2-E. Spray Rinse-3.0 onto leather and agitate with brush-1.

    2-F. Extract suspended soiling with a terry cloth towel before it dries.

    2-G. Proceed immediately to Conditioning step-3 and keep the moisture content up.


    3. Leather Structure Conditioning for Suppleness:

    3-A. The purpose of this step is to rejuvenate the leather by replenishing the moisture, fat and oils in the leather which will increase the softness, plumpness, and strength of the leather.

    Apply Hydrator-3.3 to pre-condition the leather. Use brush-1 to agitate and remove surface soiling. Extract with a terry cloth towel until the towel shows clean.

    3-B. Re-apply Hydrator-3.3 with the foam brush and allow it to be absorbed into the leather. Apply paper towels-5 to the leather surface without air gaps and saturate with Hydrator-
    3.3. Apply a cling wrapper over the paper towels to control evaporation. Check dryness of leather and re-apply Hydrator-3.3 often. The leather must be maintained wet.

    3-C. The cling wrap can be left on for up to 72hrs to soften up the leather structure. There should be a little moisture oozing out when pressed with fingers and thumb to have the hydration at its optimum level during this dwell time.

    3-D. When the leather is limp and soft, the cling wrapper can be removed and soiling is extracted with a terry cloth towel until the towel shows clean.

    3-E. While still damp, spray Fatliquor-5.0 onto the leather and spread with the foam brush so as to be fully absorbed by the leather. Re-apply as needed. In each application cycle, 83.33% of the fatliquor water content needs to be evaporated. It is only 16.66% of the fat and oil contents that are essential to supple up the leather. The fat plumps the leather and the oil lubricates for softness. When the Fatliquor-5.0 application pools on the surface, this indicates sufficient absorption has occurred.

    3-F. Let the leather dry naturally without applied heat. When a surface shine appears, remove it with Hydrator-3.3 until the milky residue is removed from the surface.




    4. Leather Structure Strengthening:

    4-A. The purpose of this Strengthening step-4 is to seal, strengthen, and level out uneven absorption for the color coat process. It fills and tightens with good leveling properties that are film-forming to improve abrasion resistance. It is meant to work on below-surface weakness or over-stretching, especially the creases in the leather.

    4-B. Shake well and apply Impregnator-26 with brush-1 to saturate all weak, overstretched, and highly absorbent damaged areas.

    4-C. Concentrate on weak areas. Wipe off unnecessary excess to prevent build-up.

    4-D. Use Hydrator-3.3 to wipe surface residue to avoid the use of the sandpaper.


    5. Primer/Sealer Coating:

    5-A. The purpose of this Prime step-5 is to ensure proper sealing and adhesion of the color coat.

    5-B. Shake well, spread Adhesor-73, and etch evenly with a 3M white Scotch-Brite pad (2500) to work into grooves and worn areas. Wipe away any deteriorating finishes and the excess with a white terry cloth towel, until the towel shows clean.


    6. Color Coating:

    6-A. The purpose of this Color Coat step-6 is the application of the color coatings. Micro-54 is designed for micro pigmented leathers also known as semi-aniline. This is a water-based opaque pigment color coat.

    6-B. Mix Micro-54 and an auxiliary leather Thickener-48 to stabilize and reduce flow of the color coating during spraying.

    6-C. The first coat is applied with a foam brush. This is done to work the color into hard to reach areas and to also minimize later spray applications. Dab the foam brush onto the leather and avoid creating streaks.

    6-D. The next step is to spray the color coatings onto the leather using the airbrush to produce a uniform and professional appearance.

    6-E. Setup an airbrush for spraying and adjust air pressure for a proper pattern.

    6-F. Working with one seat panel at a time, first spray the seams and around the edges. Then proceed to spray on thin coats, overlapping 50%, until it looks nice and uniform.

    6-G. Allow each coat to dry before spraying the next. Accelerate drying with a hairdryer.

    6-H. Let dry naturally or speed dry with a hairdryer.


    7. Top Coating:

    7-A. The purpose of this Topcoat step-7 is to provide a thin but tough clear polyurethane finish to protect the color coat against abrasion and wear. MicroTop-54 is the matching sealing topcoat in this pigment series system. Duller-63 is used to adjust the surface sheen. BMW Nappa Leather should have a semi-matte appearance.

    7-B. To adjust the surface sheen for semi-matte, mix MicroTop-54G (Gloss) with Duller-63 by adding approximately 35% Duller-63.

    7-C. Setup airbrush for spraying and adjust air pressure for a proper pattern.

    7-D. Apply a light coat and allow it to dry. Accelerate drying with a hairdryer. Apply 2 more light coats or as needed.


    8. Rub-Resistant Protection:

    8-A. The purpose of this Protection step-8 is to provide non-stick, rub-resistant protection to the leather and impart a leather-like scent.

    8-B. Shake well, spray Protector-B+ onto the leather, and spread with a foam brush. It is ready to use when dry.

    8-C. This is a sacrificial protection layer and must be replenished periodically. Re-apply every couple of months or as necessary.

  17. #17
    Join Date
    Apr 2020
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    14

    Default sander clarification

    Quote Originally Posted by Roger Koh View Post

    Oscillator Sander
    Do you mean a random orbital sander?

    Could you clarify when this would be used?

  18. #18
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
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    4,655

    Default

    >>> Do you mean a random orbital sander?

    A sander that is not rotary, but orbital or oscillate that has less chances to cut into the leather in motion.


    >>> Could you clarify when this would be used?

    A velcro sand disc is attached for dry or wet sanding during the stripping or dry prep process.

    The topcoat that is to be removed has a whitish powder when it produces a color residue, it is time to slow down or stop.

  19. #19
    Join Date
    Apr 2020
    Posts
    14

    Default

    Quote Originally Posted by Roger Koh View Post
    >>> Do you mean a random orbital sander?

    A sander that is not rotary, but orbital or oscillate that has less chances to cut into the leather in motion.


    >>> Could you clarify when this would be used?

    A velcro sand disc is attached for dry or wet sanding during the stripping or dry prep process.

    The topcoat that is to be removed has a whitish powder when it produces a color residue, it is time to slow down or stop.
    I was originally thinking that the topcoat finisher would only need a slight scoring with a grey 3m scotch-brite pad (600-800) and then Stripper-2.3 would be applied to complete the topcoat finish removal.

    But now, if I understand correctly, the stripping process is to first sand down the topcoat finish to the color coat. That point is reached when the sanding residue changes from white (topcoat) to black (the color coat in this case). Then Stripper-2.3 is applied to complete the removal of the finisher and color coat residue. Then another round of sanding to smooth the surface.

    So rather than rely mainly upon a chemical process to remove the finisher, a mechanical removal of the majority of the finish coat is performed followed by a small chemical removal step.

    Does that sound right?

  20. #20
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
    Posts
    4,655

    Default

    Yes, without a sander, it is quite impossible to finishes, they are tough.
    So a combination of the mechanical and chemical processes will shorten the stripping process.
    Both mechanical and chemical have their pros and cons and we want to utilize the pros from both means.
    The saying, there are many ways to skin a cat, applies to the person that has different skill levels. As long as the finished is removed without physical and chemical damages to the leather structure you are right in your own way. Remember, Stripper-2.3 has a pH value of 2.3, but that does not mean it will not dissolve the fat and oil but is safe to the tanning agents and the dyestuff only.

  21. #21
    Join Date
    Feb 2007
    Location
    Greater Vancouver, Canada.
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    4,655

    Default

    Use this system in combination with Stripper-2.3 . . .

    Stripper-2.3 > Hydrator-3.3 > Fatliquor-5.0 > Hydrator-3.3 as a continuous wet system to replenish the fat and oil removed at the same time. The fat and oil replenishing will ensure that existing leather dryness and cracks are not magnified or made worse. Fatliquor is the lifeblood of leather. Just like an operation will need blood replenishing, to stay alive after the operation, make sense?

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