Sunday, 6 August 2017

Various Leather Surface Conditions / Repair


How your leather feels (its Patina – literally ‘hand’) tells you more about its condition than anything; it should feel like something between velvet and satin. Supple, inviting and luxurious. Leather care starts with maintaining factory fresh feeling leather from the beginning. Keeping it clean is important, and hydration is the key; preserving the life, flexibility, appearance and longevity of your leather.
1. Burns or torn vinyl / leather –scrape away any burned edges and cut off any rough and / or frayed particles. Obtain a piece of vinyl leather and trim it slightly larger than the tear, apply a suitable adhesive (Pro Stick 65™ Hi-Strength) allowing it to become ‘tacky’. Place this sub-patch under the vinyl / leather and allow to fully dry. If necessary, use (Leather Magic!) filler to level the surface; use several light coats of filler and allow to dry between coats.

You can use a hair dryer to assist in drying. Remember to hold hair dry at a 300 angle. After the leather repair is level, apply a colour dye to match if required

2. Bolster abrasions - it will depend on how badly the leather is abraded. Most bolsters have sections where the leather is more worn than others. If it is heavily worn, the leather can be very thin. You can tell by pinching the leather to see if it is paper thin. Too much sanding will result in burning through the leather. Lightly sand the finish and then apply a filler

3. Cracking – keeping leather clean is the key to finished leathers durability, it is the combination of dirt and abrasion that causes the finish to crack and deteriorate over time. It is the pigment/finish coating that cracks and not the leather itself so keeping the leather clean will help prevent dirt from causing a problem.
Urethane upholstery fibre structure will stretch in all directions with no particular grain or stress pattern. The urethane surface coating will not withstand multi directional stress, however, and when it’s flexed or stretched continuously in the same place the surface coating develops minute cracks.
Repeated flexing and stretching eventually causes what appears to be a ‘cracks’ in the surface coating, but is usually the pigmentation taking on wear pattern or directional creasing   

If the finished leathers urethane pigment coating has begun to fail (micro cracking) which cannot be seen with the naked eye but will make the leather appear dirty especially on light coloured leather. Steam or cleaning products may permeate the between the hide and the pigmentation coating causing it to delaminate (separate)
Leather Repair Compound (DT-152 Leather Magic) this is a water base filler material which is air dried requiring no heat to cure. When cured, this material remains totally flexible and natural feeling just like the original leather. It is a thick, paste compound which may be easily worked into crevices and cracks in order to bond the separated leather together permanently and fill crevices completely flush with the surrounding surface areas.

Cracked and / or faded surfaces need to be correctly prepped and then re-dyed. By using an aqueous (water-based) pigmentation product like this kit from Leather Magic; wipe the leather down with the solution, using the 220 grit sand paper; this will remove most of the minor creases and provide a 'key' for the pigmentation. Apply 3-4 thin coats of colour (allow to dry between coats) you have the option to spray the final coat with a sprayer (all included in kit) – Leather Magic Repair. And then add a clear topcoat for surface abrasion protection

4. Creasing - automotive finished leather is a multi-strata material, it comprises; a water-based urethane pigmentation (colour) to provide both an even colour and protection from wear when getting in and out of the vehicle and a thin water-based urethane (Ethyl carbamate) used for protecting automobile upholstery.
If dirt and / or abrasive grit are allowed to remain in these creases it will abrade the surface, eventually causing the leather to split along the crease lines, dirt in these crease lines also makes the surface appearance appear worse than it is, especially on light coloured finished leather.
So keeping the finished leather surface clean is very important. If the finished leather creases have become excessive the pigmentation and / or the urethane can be renovated. (See also Wrinkle’s)
5. Wrinkle’s - similar to a paints clear coat, upholstery urethane 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 and is therefore subject to show wrinkle’s.

These can be lessened by using a damp (microwave heated) towel, which will cause the urethane to contract slightly. The foam, leather hide and its urethane covering are subjected to compression (the weight applied by people sitting on them) which causes them the stretch, which in turn produces creases (wrinkles). If they become excessive it may mean that the foam is compressed to the point it will no longer ‘rebound’ and should therefore be replaced (See also Creasing)

6. Dry leather - it is the moisture level that has altered and re-hydration is needed to restore balance. Keeping leather clean and hydrated is the key to maintaining leather and although commercial 'conditioners' may 'feel good it's not the leather itself that feels softer, but merely the product sitting on the surface. (See also Moisture Content)

7. Damaged or Torn Stitching - an oil-based product will attract abrasive dirt and permeated the leather via the stitching, the oil will soften the leather, and the abrasive dirt plus friction will caused the leather and stitches to tear. To stitch leather properly, you need specialist tools, its s not like stitching fabric as the leather is thick and resists piercing.

There are a host of problems unique to stitching leather, and there is an array of specialized tools just for this process. The needles tend to be much larger than needles that are meant for sewing cloth, these have triangular points which cut through the leather.

 Waxed polyurethane, linen or canvas thread is usually used for stitching. The use of an awls and a pinwheel requires that the leather to be resting against a firm surface, usually a small wooden block, so you need to remove the hide from the foam underneath to re-stitch leather.

8. Deformed leather surface – similar to a paints clear coat, upholstery urethane 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 foam is subjected to compression, while the leather hide and urethane are under tension. Compression of the taught urethane / leather hide causes stretch marks.

The application of low pressure / dry vapour steam will help restore the shape, used in conjunction with hand pressure. Steaming is what the factory does to mould the leather around all the curves of seats and interior panels, and upholsters use to stretch or reshape leather.
Place a damp micro fibre towel in the microwave and heat for a few minutes - until they are really hot but not so hot that you can't touch them. Place on the seats and leave for a few minutes - great at removing ingrained dirt too.
9. Delamination –occurs when the pigmented urethane protection separates from the leather substrate. If oil is allowed to permeate any micro fissures in the leather or via the stitching it will compromise the resin binder system and delaminate from the hide releasing its adhesive bond, and it will be able to move in a different direction from the hide, which will result in surface fissures and cracking, further compounding the problem eventually leading to the subsequent replacement of the protective (urethane) covering

10. Holes or Tears can be repaired by cleaning any rough or frayed edges and then placing a sub-patch of backing material that is larger than the hole must then be secured in place by means of a sub-patch and adhesive to give the leather patch something to anchor to. Before you insert the backing piece cover it with adhesive, allow the adhesive to become tacky.
Take a piece of circular leather cut to a half inch larger all round than hole and hold it in place with adhesive applied to the sub-patch backing piece. Pro Stick 65™ Hi-Strength- spray adhesive for bonding foams, carpet and upholstery
11. Leather pigment restoration – kits available that allows you to recolour worn and faded leather easily. The colour coat provided is a water- based material, colour matched, that is designed to be highly compatible with leather, and provides a long lasting finish– Leather Magic 

12. Loose covers- the urethane pigmentation upholstery fibre structure of finished leather is designed to stretch along with its substrate, however sometimes it becomes over-stretched and in some instances can be rectified by dampening the surface and then applying heat it’s possible that the surface will tighten up. Dampen the surface (do not soak) with distilled water and then position the end of a hair dryer eight to 10 inches away from the wrinkled leather surface. Move the end back and forth so that the hot air is not concentrated on one section of the leather for too long. This prevents the dryer from burning the leather.
The heat from the hot air in the dryer will gradually shrink the finished leather, tightening its surface (this is the way leather is fitted in upholstery shops, i.e. shrink to fit) and effectively removing the wrinkles.
Hair dryers operate at a lower temperature than professional heat guns that are typically used to shrink fit leather. As a result, it might be several minutes before the wrinkles are completely gone.
Loose covers could be caused by foam padding compression, which will require replacement. Also be cognizant that if oils have permeated between the hide and the pigmentation coating it may have become delaminated, which means the two surfaces are moving independently
13. Pigmentation (Colour) Replacement - Certain areas of your vehicles leather interior like seats, upholstery, side mouldings 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

14. Scuffed (Covered) leather - use a hair drier (not a heat gun) at a 300 angle to heat the area while massaging it, this will lift the scuff out. Then apply LM Leather Protection. If it is still noticeable then treat it like a leather repair.

15. Stiff leather surface – Soft Touch will soften leather that has become dried out, stiff or is squeaking. It is also excellent for improving the tactile feel of leathers.

16. 1z Plastic Cleaner (Plastik-Reiniger) was originally developed to protect vinyl tops from oxidation and embedded dirt build-up. Clear-Cote is also a protective coating for newly refinished leather or vinyl.  It provides a durable, washable surface for any leather or vinyl upholstery; available in original gloss or matte finish. Use a fast-drying lacquer thinner to remove the old colour coating. Apply colour, allow drying thoroughly and then applying Color-Plus

17. Squeaky leather – see Leather Soft Touch

18. Urethane surface scratches - for light slightly scuffed finished leather upholstery; use a 2000 grit finishing paper, with light pressure sand the area until the marks have faded. Then use a very thin application of Leather Master’s Leather Filler, water- based acrylic paste that fills out scratches in leather or any part of that grain that is missing.

19. Scratched leather – Removing Scratches
Leather will age from abrasion (scuffs) and collect light scratches from keys, boxes, and just about any item you place on its surface.
1. Leather Master™ Scratch Away – (A-Aniline/Non-Coated only) a professional formula designed to erase these light surface scratches and scuffs. It performs this amazing feat by moving the surrounding dye to cover the area where the colour is missing.
Application:
· Apply a small amount to your fingertip (we suggest using a plastic glove).
· Dab over the surrounding area, slowly working toward the damaged area until the scratch or scuff disappears.
· DO NOT wipe with a towel while this product is still damp!
· Allow to completely dry and then apply Leather Master™ Protection Cream.

Finished leather suffers from abrasion wear over time or can be scratched from items you place on its surface.
2. Magic Mender - (P-Protected / Coated) most scratches to finished leather or vinyl can be repaired with just a few simple products. All it requires is a properly clean and prepared surface, a professional quality repair compound and a correctly colour-matched finish top coating
Application:
· Clean the surface you're going to repair
· Apply Magic Mender leather repair compound and allow to dry
· Brush-on or spray Color-Flex final colour finish for a flexible, long lasting repair - http://www.leatherrepairkits.com/

20. Urethane covered hides - the oils secreted from your skin are slightly acidic and may compromise the urethane covering. Removing these oils is paramount to leather care, but limiting the amount of bare skin you expose to your seats and interior is a great way to prevent discoloration.
 Once damage to the extent of cracking is apparent on urethane covered upholstery, there is no way to restore them to original factory condition without re-finishing them.

21. Shiny Surface – OEM leather upholstery should have a matte look. If dirt and / or grit are allowed to remain on the surface it will abrade the surface and make it ‘shiny’, eventually causing the leather to split along the crease lines, dirt in these crease lines also makes the surface appearance appear worse than it is, especially on light coloured finished leather. So keeping the finished leather surface clean is very important. If the finished leather has become excessive the pigmentation and / or the urethane can be renovated.
Vacuum to remove any loose dust / dirt and then wipe with a damp 100% cotton micro fibre towel. Periodically clean using Iz einszett 'Plastik-Reiniger' is an intensive, non-corrosive, non-acidic two-phase deep cleaner that contains anti-static and produces a matte satin finish. Spray surfaces with 1z einszett Plastik Reiniger. Work the cleaning solution into seams, edges and seat backs using a medium soft bristle upholstery brush. If necessary, use an old toothbrush to get into the small crevices.
22. Tree Sap / Resin- use an aerosol compressed air computer cleaner (alternatively use an ice cube) the refrigerant it contains will ‘freeze’ the resin and it can then be carefully scraped off with a plastic razor blade

23. Leather cracks - this is the cause of leather cracking. The interior layer of the leather is a collection of Omni-directional fibres. These fibres’ hold residual oil (fat liquoring) and moisture. Over time, the moisture evaporates through the pores of the leather. As the leather hide loses moisture, it begins to shrink and stiffen. This leaves a miniscule gap between the leather hide and the colour coating on top of it. The colour coating is no longer supported by the hide. Without proper support, it starts to crack. The cracking you see on your seats starts in the colour coating. Without treatment, the cracks can become severe

24. Water Ingress Damaged Surfaces - by inadvertently leaving a moon roof, convertible top or vehicles windows open during a rain storm will very likely soak the leather seating and perhaps the carpets. The damage would depend on how long it's exposed to water, restoration is important because it may become a breeding ground for mould and mildew. Left for a couple of weeks your whole interior would probably have to be replaced.

There are no leather finishes that are water proof. Leather hides used for automotive upholstery consist of approximately 45 square feet, that are stitched together to form a covering. The thousands of stitch holes allow any standing water to be absorbed and migrate laterally under the urethane finish. The perforated leathers used on many BMW, Mercedes-Benz, Porsches and other cars also allow standing water to permeate the urethane.

Leather that has been soaked in water may become brittle and may be ruined due to the formation of water mark stains and blemishes. Water damage restoration for leather is very manageable using the correct products and methodologies. When leather becomes soaked or wet, the best way to dry it is to use clean, dry towels to wipe away the water. Never dry leather using a heater as this will cause the leather to shrink rapidly, causing further drying and cracking.

Finished leather (urethane pigmentation) is water resistant, which means if you spill or allow liquid onto the surface and clean it right away it should not cause problems. Damage to the electronics that are under the seats (seatbelt sensor, seat positioning motor, air bag sensors, and etc) may be a cause for concern.

Obviously the amount of damage could be lessened dependent upon how quickly action was taken. If you saw it immediately, and got it home quickly and dried it out using towels to soak up the rain water, most things would be okay.

Restoration
Avoid flexing or bending the leather while you are restoring it because leather is weakened when the fibres are dry and it may crack.

Wet a towel with warm water, wringing out excess. Proceed to wipe the leather to remove any dirt and moisten the surface. If you are working on a large item, do one section at a time so you can apply Leather Master™ Soft Touch, while the surface is still moist. This is not a conditioner per se; it contains polymers in an aqueous emulsion and is used to improve and maintain the tactile feel and lustre by rehydration and to ensure the leather remains matte, soft and supple.

Apply a small amount to a clean, damp 100% cotton micro fibre towel, use a circular motion and slight pressure to ensure the product permeates the dried-out pores, but do not push hard enough to damage the leather. Allow 20-30 minutes’ dwell time; unless the damage is severe, it should soften up after you massage it for a few minutes and then wipe surface with a dry 100% cotton micro fibre towel.

Although water (hydration) is good for leather and is what keeps it in good condition generally when its fibres become over soaked they swell and become deformed. When they dry they may not shrink back and revert to their original form and so become more brittle and distorted. Unfortunately, at this stage it may be impossible to rectify.

Protected 
With leather, it is much easier to practice prevention than it is to try to resolve major challenges after the fact. Leather Protection will also work to remove small surface scratches on finished leathers. In general, Leather Protection Cream is used as a final step in combination with most of the Leather Master products.

This is essential as it will protect the surface finish (Leather Master™ - Protection Cream, a Scotchgard™ type, water-based product) as a sacrificial layer; this way you are not actually cleaning the Leather's original surface, but cleaning from the surface of the protection. It also makes dirt easier to clean off

The polymers penetrate the surface of finished leather and cross-link to form a durable protective film that is breathable, allowing transpiration and keeps the leather supple. Being aqueous (water- based) it restores moisture to finished leather and provides a protective sacrificial barrier against all kinds of soiling, water, oil, alcohol-based stains and perspiration marks, so you are cleaning the protective layer

No comments:

Post a Comment