Removing Stains from Leather

Materials Technology 

Automotive OEM technology is becoming more and more complex requiring educated and skilled technicians to work on them. As the materials used are constantly changing we must maintain our knowledge base and utilize the correct products and application methodologies to keep up with emerging technologies.

Automobile manufacturers have blurred the distinguishing lines on what exactly leather is. There are many so-called ‘leathers’ that are actually the bottom split (the fibrous part of the hide) which are covered with a vinyl or urethane coating. Diagnosis is the key, not guess work. Before deciding on what products to use, you need to ascertain the grade of leather and the type of leather finish applied

Be cognizant that the leather and finishes used for automotive upholstery varies from leather industry standard descriptions and although the names are similar the type of leather, pigmentation and finish are often very different.

 So it is very important to be able to recognise the various finishes and materials used by OEM’s as they all require different methodologies and products for proper care and maintenance.

Automobile model ranges use different materials for their vehicles interiors; leather upholstery like Aniline Immersion Dyed, Aniline Micro Pigmented, (Urethane) Finished, Artificial leather such as MB-Tex and unfinished materials like Synthetics and Alcantara, and sometimes combinations of products (Alcantara seat inserts on leather seating) as well as various grades of leather hide, full-grain, top-grain and split –grain (which is protected with urethane) all of which require different products and applications methods

Pre-test Spot Procedures

Diagnosis is the key, not guess work. Before using a cleaning product, a detailer needs to know the material they are working on, what they are trying to remove and wither the product chosen is compatible with the material and will not damage it.

With all cleaning products, always test a small, inconspicuous area first to ensure it won't discolour or stain the surface, and ensure that the pH of the product is suitable for the material. As can be seen stain removal requires some knowledge of basic chemistry.

Surface checks

·         Identifying characteristics

·         The water-drop absorbency test

·         Absorbency rate

Read the product labels and manufacturers safety data sheets (MSDS) to obtain a basic idea of contents, pH levels etc. Depending on the pH of the product you use you should return the surface to neutral (pH 7.0) before you apply any dressing or protective products.

Always select a chemical / cleaner that are biodegradable, environmentally friendly and safe to use by observing any precautions recommended so that they won’t harm you, your vehicle or the environment. Read the product labels and manufacturers safety data sheets (MSDS) to obtain a basic idea of contents, pH levels etc.

Testing cleaners on an inconspicuous area is the best way to ensure there are no surprises as to its affect, but be cognizant that it may not react in exactly the same way as a heavily soiled area or that has been subjected to UV-B radiation (faded) When spraying any surface with a liquid, it is always advisable to spray a small area first (test area) then allow to dry to make sure the solution does not react with the surface.

Providing the cleaning product selected is suitable, apply several drops of the selected cleaning solution onto a 100% cotton micro fibre towel and rub gently. Do not over wet. Use small amounts of the product and blot frequently, do not rub or use too much pressure.  

Do not use the product if it adversely changes the surface colour or texture.

Surface Cleaning Methodology

Leather is only damaged by dirt and if it becomes completely dehydration (or over soaking as the fibres swell and then distort) Before using a cleaning product a detailer needs to know the material they are working on, what they are trying to remove and wither the product chosen is compatible with the material and will not damage it.

Diagnosis is the key, not guess work. With all cleaning products, always test a small, inconspicuous area first to ensure it won't discolour or stain the surface, and ensure that the pH of the product is suitable for the material.

As can be seen stain removal requires some knowledge of basic chemistry. Read the product labels and manufacturers safety data sheets (MSDS) to obtain a basic idea of contents, pH levels etc. Always select a cleaner that are biodegradable, environmentally friendly and safe to use by observing any precautions recommended so that they won’t harm you, your vehicle or the environment

Clean the leather area(s) once every two weeks with a clean, cotton cloth that is damp (not wet).  Hydration is the most important thing you can do to keep your leather supple and looking new.

Proper vacuuming is extremely important; use the soft brush attachment connected to a very strong vacuum cleaner to clean deep the stitching and crevices (especially important with perforated leather). This removes the embedded dirt/dust and clothing fibres.

•         Using a soft brush remove light dust from surface

•         Vacuum surface

•         Apply surface care products with a 100% cotton micro fibre towel 

•         Wipe area with a damp 100% cotton micro fibre towel to hydrate surface

•         Use a suitable spot cleaner as required

•         Use a Urethane or an Aniline leather cleaning product (dependent upon ‘leather’ type)

•         Apply ultra violet (UV) and / or surface protection product

The advantage of foam or gel over liquid is the minimum amount of moisture they contain, very important for cleaning absorbent materials. Spray onto an applicator; do not spray directly onto the surface as it could cause spotting. 

Allowed to remain in place these types of cleaners gently loosen and encapsulate surface dirt and grime so it can be gently wiped away. For heavily soiled areas, or where the soil has become ingrained such as in creases in the leather, a soft brush can be used to agitate and loosen the dirt.

For heavily soiled areas use a foam cleaner (Leather Master™ Foam Cleaner) that contains a surfactant that will lift dirt and soil, allow react time to do its work and then use a soft brush to agitate and loosen the dirt (Swissvax Leather Brush) especially on light coloured leathers; this enables the cleaning of the micro pores and creases and lifts the dirt out and reveal any further work that needs doing (dye transfer, stains, etc.)

Alternative: Leather Master™ Strong Cleaner Wipes - contains a highly effective detergent for stubborn dirt. It can be used on all type of leather except Nubuck and Alcantara®  .

Choosing a Leather Care Product

The most important consideration in leather care is to identify the finished leather used. Once you’ve correctly identified the leather and / or the applied finish applicable to your vehicle's upholstery, it’s easier to select suitable products / methods (one size fits all is just a vendor's marketing myth) First you need to identify the material and finishes used; Aniline and Protected or Coated

Different types of leather require specific cleaning and care and therefore require a slightly different process. Check your 'leather type' before attempting to clean or apply any products to its surface.

Leather Master Products are used as a ‘benchmark’ by other leather care product vendors. All aqueous (water- based) cleaners will remove any body oil or salts, dirt and grime and wash them from the leather surface.

Today, Leather Masters™ leads the industry with over 350 different leather products. All Leather Masters™ products are manufactured in Montecchio Maggiore, Italy.

The world's largest tannery, located nearby, keeps them up to date on the latest changes within the industry. As an added bonus you’ll use a lesser amount of product with superior results.

The complex tanning process of chromed tanned hides results in the fat liquoring and oils necessary to keep the hide soft and pliable being locked in, this is further sealed by a durable polyethylene covering to protect the hide from abrasion from clothing as well as the dust / dirt introduced by the vehicle’s AC system.

Leather Cleaning Tools

·         A soft upholstery brush (Swissvax Leather Brush) – http//: www. detailersdomain.com

·         A soft (CCS Euro Foam Applicator) sponge for cleaner application

·         AG Hi Tech Cleaning Pads specially designed to enhance the cleaning power and performance of cleaners on a wide variety of interior surfaces.

·         100% cotton 100% cotton micro fibre towel towels (for Aniline leather) (Swisswax)

·         3M delicate duty scuff pad (White)

·         DI Accessories Terry Cloth Applicator (for urethane covered) leather

Foam Cleaner

Foam from a solvent free pump action dispenser is extremely efficient for the cleaning of leather upholstery as it lifts and encapsulates dirt to enable it to be safely removed without scratching the surface. The foam created by an aerosol or pump type dispenser has the consistency of shaving cream, making it ideal for leather

Leather Master Rapid S Cleaner (A-Aniline / Non-Coated) (P-Protected / Coated) is a concentrated cleaner specifically designed for automotive leather (including Nappa and Perforated) that have accumulated dirt, soil, and dye transfer and body oils.

Dispense foam onto the car seats, work foam into the surface with a dampened sponge, allowing it to sit for one minute and wipe the foam away with a clean 100% cotton micro fibre towel, and then protect with Protection Cream once dry do not allow a leather protection product to dry as it can leave spotting

For heavily soiled areas, or where the leather has become engrained with creases in the leather, a soft brush can be used to agitate and loosen the dirt (Swissvax Leather Brush)

Stains

(See also Leather Protection) The first thing you should do upon discovering a stain is to act immediately. Don’t wait because heat and/or time will just cause the stain to set in deeper, resist the urge to rub or wet it as this will make it much harder to remove. Be patient, some stains respond slowly, some stains cannot be removed due to differences in fibres, dyes, construction of fabric, finishes, etc.; this would also depend on the length of time the stain has remained on the fabric. Some stains will require professional treatment and/or re- dyeing.

Before deciding upon treatment, you should first access what ‘type’ of stain it is, before a stain can be removed the surface tension that bonds it must be released, then the stain encapsulated and held in suspension to be removed. With all cleaning products, always test a small, inconspicuous area first to ensure it won't discolour the surface, and ensure that the pH of the product is suitable for the material.

Since perspiration and oils are a major stain factor in leather, be cognizant of bare skin when you are in your vehicle.

a) Perspiration

(Transpiration) consists mainly of water, but also contains minerals, lactate, sodium and urea. It will leave a white residue, as it is slightly acidic it will stain, and should be removed from the surface ASAP (See also Body Oils)

b) Body Oils

If you use suntan lotion or Spray Tan, be sure to use a towel when you get back in your vehicle so that the oil does not get onto your leather. You can also use a towel when leaving the gym as body oils/ perspiration contain organic acids that will stain. (See also Oil and oil-based Products)

c) Blood

Is an organic stain and should be removed as soon as possible; if it sets it will be more difficult to remove. Once the stain has been removed the area should also be treated with a disinfectant (Lysol™ Disinfectant).

Take all necessary precautions when dealing with blood (latex cloves, and etc.) and when disposing of blood stained items.

Wipe down the area with a damp 100% cotton micro fibre towel and remove blood stains using a 2:1 solution cold distilled water / Hydrogen peroxide, this will eliminate the blood and provide a disinfectant. Finally, thoroughly rinse the area with a damp 100% cotton micro fibre towel as hydrogen peroxide will ‘bleach’ the leather if allowed to remain

d) Pet stains and odour

An organic stain that should be removed as soon as possible by using specially formulated enzyme action cleaner to eliminate odours caused by pet urine or vomit to digest the stains and odours left behind by pet urine and faeces. (Petastic Naturals)

e) Dye Transfer 

Colour transfer, sometimes called crocking. Crocking is where the dye will abrade the top coat layer of the leather. Leather Master Leather Dye Transfer Cleaner - (A-Aniline / Non-Coated) (P-Protected / Coated) dye transfer is a specialized cleaner and stain remover designed to eliminate colour and dye transfers on light types leathers. Use for the removal of blue jean transfer, newspaper print and deep stains like mustard on protected finished leathers. This product works, even when nothing else will. 

Often on light-colour leathers, it appears that the colour is coming off the leather because you can only see the surface. What has actually happened is a transfer of a lighter colour to the leather's surface from blue jeans and/or newspaper print.

If the dye has permeated then the finish should be softened to help release the dye (Leather Master Soft Touch) Using a strong solvent on leather that has a stain or dye transfer will do two things; cause the dye to ‘bleed’ further into the surface making it even more difficult to remove, and it may damage the finish requiring replacement.

As always with stain removal; start with the least invasive first.

1.      Isopropyl alcohol (IPA)

2.      A 1:1 solvent / detergent solution; d-limonene based (citrus) solvent (P21S® Total Auto Wash) and a slightly alkaline detergent.

You may not see complete removal immediately; check your results after a few hours. If you have tried appropriate leather cleaning products with no success it does not mean that the products do not work, simply that the problem is not a 'cleaning' one and the dye transfer is more severe or has been on too long

The surface may require re-coloring with a very light pigment coating applied to recolor. This would not require a full recolor as long as you had a pigment that matched the leather.

Use Leatherequi Super Prepping Agent and 1000 grit finishing paper, lightly wet sand the leather. Wipe surface with soft 100% cotton micro fibre towel to remove as much of the faded or oxidized leather dye as possible. Re-dye the leather.

            f) Coffee

If the coffee has permeated the leather and left a stain, there is nothing that will remove it as the surface has been dyed. If the stain is on the surface (see Leather Master Super Remover) but will not clean off, then the colour will need to be restored and refinished.

g) Ink Stains

Sadly, the prognosis on ink stains or colour transfer on leather is not good; as the stain permeates the leather and dyes it, and for this reason it is not easily released, especially if it has been allowed to set.

Aniline leathers have an aqueous (water- based) pigmentation that is absorbent, so an ink stain will permeate the leather hide, dyeing it, making it almost impossible to remove.

Urethane coated leather are also aqueous (water- based), so inks and dyes will permeate and be absorbed by the clear protective lacquer. Therefore, the only way to remove the stain is to remove this clear lacquer.

Hairspray is a solution of long, chainlike polymer molecules in a very volatile solvent, this solute is waterproof, which interferes with surface transpiration making it difficult to hydrate the leather. Some use butane as its carrier / propellant system, which will discolour finished leather turning it yellow. 

The nozzle and spray system atomizes the solvents into micro particulates allowing it to permeate both the finish and the leather hide, dissolving the pigmentation (colour) and the clear protective urethane. Compromising the leather finish means that the leather absorbs dirt immediately, and this is not easily removed. It also dilutes the stain and helps it to permeate both the urethane protection and the leather hide.. 

Using household cleaners will usually exasperate the problem

1. Ink Away Ink Remover (P-Protected / Coated) is designed for removal of recent (within 48 hours) ink contamination. Ink marks older than 3-5 days may not respond or will only be lightened (see Strong Effect Cleaner). The biodegradable formula is very easy to use (wax-like stick container) and works well for all types of ink as well as lipstick

2. Professional Ink Remover  - safely removes ink from: automotive interior surfaces, leather & cloth upholstery, headliners, sun visors, and vinyl and plastic surfaces.

3. Leather Master Super Remover  - for removing dye transfer, blue jean, newspaper print and deep stains like mustard on protected leathers. This product works, even when nothing else will. Often on light-colour leathers, it appears that the colour is coming off the leather because you can only see the surface. What has actually happened is a transfer of a lighter colour to the leather's surface from blue jeans and/or newspaper print.

4. Strong Effect Cleaner - ) Leather Master's "Strong Cleaner" is arguably the most effective leather cleaner on the market.

5. If the above cleaner has not removed the ink try a ‘safe’ solvent (Cliptone GT14 Safety Solvent Cleaner, A-Aniline / Non-Coated) (P-Protected / Coated) on a clean 100% cotton micro fibre towel, pat the stain using light pressure, this will break up the ink dyes, and make it easier to wipe off. Do not rub affected area otherwise it will thin out and may spread the dye

h) Nail Polish

Most nail polishes are made of nitrocellulose dissolved in a solvent (e.g. butyl acetate or ethyl acetate) which will damage the finish and may remove the top coating (urethane) on finished leather.

1.      Removing nail polish from leather can be tricky and time consuming. Always test the leather before trying any chemicals; if it is not tested, the leather could be damaged beyond repair

2.      Acetone is a strong solvent, but can be used if you work very carefully, generally acetone will damage the finish and remove the top coating (urethane) on finished leather. Gently dab using a paper towel, don’t rub the nail polish as this will exacerbate the problem by spreading the polish. Then test the leather for colour fastness. This will help you determine if the leather can withstand the chemicals needed to clean it.

3.      It would be safer to use foam cleaner (Leather Master™ Foam Cleaner) which given time may soften it enough to enable its removal with a plastic razor blade. If the foam doesn’t soften it sufficiently use a safe solvent (Wurth Clean Solve) by applying with a small paintbrush or a cotton Q-tip on the nail polish. If the nail polish has removed some colour it may be necessary to renew the pigmentation

4.      If neither one of these methods work on your leather, contact a leather professional. They have access to more chemicals and should be able to remove the stain.

.           i) Suntan Oil

Or sunless tanning lotions- to clean leather that has oil / grease stains, there are a couple of different things to try;

a)  Leather Master Rapid S Cleaner is a concentrated cleaner specifically designed for automotive leather (including Nappa and Perforated) that have accumulated dirt, soil, and dye transfer, oil or grease and body oils.

b) If the stain is fresh it can be treated and successfully removed with cornstarch rubbed briskly into the stain with your fingers until the heat from the friction is felt. The heat loosens the oil and allows the cornstarch to absorb the oil before the leather can; if the stain has ‘set’ use baking soda and leave over-night.

c)  Leather Master Leather Degreaser, an aerosol product for cleaning oily stains; it dissolves and removes oil and grease from leather surface. This cleaner can be applied for cleaning all types of leather.

Dispense foam onto the car seats, work foam into the surface with a dampened sponge, allowing it to sit for one minute and wipe the foam away with a clean 100% cotton micro fibre towel, and then protect with Protection Cream

Finished leather - (P-Protected / Coated) Iz einszett 'Plastik-Reiniger' is an intensive, non-corrosive, non-acidic aqueous (water- based) detergent cleaner for urethane.

Prevention - since body dirt and oil are a big stain factor in leather, be cognizant of bare skin when you are in your vehicle. If you use suntan lotion a lot, be sure to use a towel when you get back in your vehicle so that the oil does not get onto your leather. You can also use a towel when leaving the gym as body oils/ perspiration contain organic acids that will stain. 

Leather Master™ - Protection Cream will provide resistance against this type of stains, spills and provides the hydration necessary to keep the leather soft and supple

j) Water marks (stains)

If there is a stain because the water has dried in the middle of a piece of leather, it has a clear point of demarcation to the rest of the leather; reduce that point of demarcation by wetting the entire cushion or area out to a seam or edge.

Take a bowl of room temp water and a clean sponge, soak the sponge wring it as dry as possible and starting at the spot dampen the leather and move the sponge to the edges of the cushion, allowing the moisture to become less and less as you get further from the spot. Do not scrub, just gently wipe.

Do not soak the leather just get it damp enough at the stain to release the stain and wet the rest of the leather so that the entire cushion can dry uniformly across the cushion rather than in that one spot. (See also Water Damage)

k) Paint

·         Do not rub or use pressure on the affected area. Pat with a dry rag to gently wipe the paint away if the stain is very fresh.

·         Try to loosen the paint with a warm water compress using a 100% cotton micro fibre towel. This should soften the paint and loosen its grip on the leather so that you can gently peel it away.

·         Clear away any excess paint by abrading the surface of dried paint with a plastic (ScrapeRite blades) or single-sided razor blade

·         Do not use paint thinner as it will cause the paint to migrate and ‘bleed’ producing a larger stain

a)      Use Leather Master™ Strong Cleaner with a 100% cotton micro fibre towel to wipe the paint off the affected area. Use a 100% cotton micro fibre towel soaked in distilled water to remove the soap. Pad gently with a dry 100% cotton micro fibre towel

b)      Or use a ‘safe’ solvent (Cliptone GT14 Safety Solvent Cleaner) on a clean 100% cotton micro fibre towel pat, this will break up the compounds of the paint, and make it easier to wipe off. Do not rub affected area otherwise it will thin out and may spread the paint.

·         Use Leather Master™ Soft Touch on a clean 100% cotton micro fibre towel, this is also recommended if the stain is fresh. Gently spread (do not rub or use pressure) the on the stain. Wait for a few minutes, and then gently pad the spot lightly with a dry 100% cotton micro fibre towel

For urethane covered leather try olive oil on a 100% cotton micro fibre towel

            l) Crayon

Abrade the crayon with a plastic razor (or a credit card) and then use a heat gun (or a hair dryer) and a towel to absorb any reside. Follow up foam leather cleaner or a leather safe degreaser and finally a leather protection cream.

            m) Wax

Freeze the wax first with an ice cube and scrape off what you can with a plastic razor blade (or the edge of an old credit card) With an all-white paper towel, set your hair dryer to the hottest setting and heat the wax wiping up the wax as it melts with the paper towel.

Stain removal products

Leather is a natural material and varies greatly between manufacturer processing and dyeing procedures, age of leather and individual hides. This is why it's so important to pre-test each cleaner for its suitability on an inconspicuous area prior to use.

1z Plastic Cleaner (Plastik-Reiniger) - an intensive, non-corrosive, non-acidic two-phase deep cleaner that removes grime build-up, scuff marks, bitumen (tar) and nicotine thoroughly and effortlessly with dust-resistant anti-static action. Use to clean armrests, door handles, shift knobs, vinyl seats, pedals, dashboard, storage compartments, tires, rocker panels, wheel wells, and etc. Water-based formula is biodegradable, silicone and formalin-free as well as environmentally friendly

Surface re-Finishing

Pigmentation (Colour) Replacement - Certain areas of your vehicles leather interior like seats, upholstery, side moldings and steering wheels inevitably start to show signs of wear, even if well taken care of, that spoil its overall impression. Often these imperfections are not serious and are simply colour that has worn off or light scratches in the leather surface which can be removed and will disappear with the right application technique and leather pigmentation. Swisswax Leather Refurbishing Pigmentation

Leather Master™ Refinish (Leather Clear Coat) – offers the most advanced, highest-grade waterborne coatings manufactured with pigments, not dyes, to give lasting durability. Oil-based leather care products can cause the urethane covering to be compromised by permeating cracks and fissures (i.e. delamination; as the oils effect the adhesive used) when refinishing leather demands lasting durability and exceptional quality this two-part system of premium coatings that delivers OEM standards.

The urethane pigmentation used for automobile upholstery is classified as a semi-solid permeable membrane, being a thermosetting polymer (elastomers) it remains flexible while retaining its tensile strength, to enable it to expand and contract, following the temperature fluctuations (elasticity) of the substrate. The urethane although very resilient to abrasion wear from entering and exiting the vehicle, by using additives it still maintains its physical properties like flexibility, tactile hand and its patina

Footnotes:

I would like to think that these articles become an asset to anyone who is new to detailing and to professional’s alike, as well as industry experts who seek to advance their knowledge.

I hope the above article was informative. By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.

I would appreciate it if you would share this article as it helps other detailers further their knowledge.

Questions and/ or constructive comments are always appreciated.

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