Monday, 17 August 2015

Tyres 101



History

Early automobile tyres were made entirely of natural white rubber; however, the white rubber did not offer sufficient traction and endurance so carbon black was added to the rubber used for the treads. Using carbon black only in the tread produced tyres with inner and outer sidewalls of white rubber. Later, entirely black tyres became available, the still extant white sidewalls being covered with a somewhat thin, black colour layer of rubber. Should a black sidewall tire have been severely scuffed against a curb the underlying white rubber would be revealed, it is in a similar manner that raised white letter (RWL) tyres are made.

Tyres
 [: Tyres or Tyres- English and American English respectively]

The tyres with the best tread should be fitted to the rear axle; as you have control of the car with the steering wheel / front tyres and you want the most traction the rear. Many modern vehicles are set-up to have the most brake pressure on the rear tyres.

If you have a blow out on the front, the steering wheel can control the vehicle direction and the rear tyres will have better grip to aid you in controlling the car. Tyre manufacturer’s and/or training by the tyre manufacture or their supplier will explain the logic for the best tyres to be fitted to the rear axle for the above reasons.

Tyres are manufactured from a composite of rubber and highly cross-linked polymers to increase durability, flexibility, toughness and prevent air loss along with compounds such as rubber with reinforcing materials such as fabric and wire, natural rubber or Polyisoprene is the basic elastomeric polymer used in tyre making. Styrene-butadiene co-polymer (SBR) is a synthetic rubber which is often substituted in part for natural rubber based on the comparative raw materials cost.



Tyre code - Automobile tyres are described by an alphanumeric code, which is generally moulded into the sidewall of the tyre. This code specifies the dimensions of the tyre, and some of its key limitations, such as load bearing ability, and maximum speed. Sometimes the inner sidewall contains information not included on the outer sidewall, and vice versa.

When referring to the purely geometrical data, a shortened form of the full notation is used. To take a common example - 195/55R16 would mean that the nominal width of the tyre is approximately 195 mm at the widest point, the height of the side-wall of the tyre is 55% of the width (107 mm in this example) and that the tyre fits 16 inch diameter wheels. The code gives a direct calculation of diameter.

Tyre Construction Materials

Natural rubber or Polyisoprene is the basic elastomers used in tyre construction. Styrene-butadiene co-polymer (SBR) is a synthetic rubber which is often substituted in part for natural rubber based on the comparative raw materials cost. Polybutadiene is used in combination with other rubbers because of its low heat build-up properties - [Source Wikipedia]

Materials used

·         Rubber - 38%
·         Fillers (carbon black, silica, carbon chalk) - 30%
·         Reinforcing materials (steel, rayon, nylon) - 16%
·         Plasticizers (oils and resins) - 10%
·         Chemicals for vulcanization – 4%
·         Chemicals as antioxidants – 1%
·         Miscellaneous – 1%

Sell By Date
Over time, rubber degrades; vehicle manufacturers recommend that tyres be replaced / not retailed (sell by date) when they are six years old to prevent sudden failure, even if the tyre looks undamaged. After this amount of time, tyres sort of internally dry-rot, which can cause the tread to delaminate, which often leads to fatal accidents? The way to check your tyres date is by looking at the end of your DOT code, it will be either 3 or 4 numbers the code on my tyre was 3705, meaning, that my tyres were made the 37th week of 2005. In tropical climates, tyres degrade sooner than in temperate climates

The National Highway Traffic Safety Administration (NHTSA) has seen reduced aging of tyres filled with nitrogen. Though the data does support that passenger car tyres could benefit by all the claims made for nitrogen, tyre manufacturers say that they already design tyres to perform well with air inflation. And while nitrogen will do no harm, manufacturers say that they don't see the need to use nitrogen, which generally adds $5 or more per tyre charge.

Tyres are subjected to more abuse than any other component part of the vehicle. Designed to perform under extreme conditions of heat via kinetic energy transfer, high speeds for long periods of time and incredible forces of torque and flexing.
As well as airborne contaminants they also have other formidable adversaries, ultra violet radiation (UVR) ozone, oxygen, petroleum distillates, formaldehyde, asphalt, road dirt and grime, and rain water. Over time, rubber degrades. 

Nitrogen

Air consists of Nitrogen (N2) 78%, Oxygen (02) 21%, Water vapours (H2O) 0.4% and other gases make up the balance Nitrogen molecules due to its inertness and lack of oxidative qualities, as opposed to air, they also have a larger effective diameter than oxygen molecules and therefore diffuse through porous substances more slowly. Nitrogen also is less sensitive temperature changes
To fill a tyre with Nitrogen, when supplied compressed in cylinders it is often referred to as oxygen-free nitrogen (OFN); after a nitrogen purge, pull a vacuum to remove any moisture, and then fill with nitrogen.

This all came from racing series where they used really wide bias ply tyres and compressed air. As these tyres are highly susceptible to expansion due to the extreme temperature effects on the moisture in the compressed air, and actually causes them to gain a measurable increase in circumference, which adversely affects the handling of the car.

To minimize this, they use compressed Nitrogen, it’s inert and therefore better for the internal tyre pressure sensors, its lack of moisture is also a factor that adds an advantage of cooler tyre running temperatures.  Nitrogen molecules are less likely to escape from the inside of a tyre compared with the traditional air mixture used. Nitrogen molecules have a larger effective diameter than oxygen molecules and therefore diffuse through porous substances more slowly

For a standard steel belted radial, normally found on automobiles and aircraft the advantages of using nitrogen in place of compressed air are negligible.

Traction Control

Anti-Lock Brake (ABS) and Traction Control(AST) Systems - while anti-lock brakes, traction control, and vehicle stability systems help make it easier to utilize your tire's full potential, none of these systems actually provides more traction. These systems are only capable of manipulating or limiting your vehicle's acceleration, braking and cornering capabilities to the traction provided by your tyres

All-Wheel Drive Systems (AWD) and Four-Wheel Drive Systems (4WD) SUVs and light trucks have become very popular among drivers living in the Snow Belt. While their year-round versatility certainly plays a role, they are often selected primarily because their all-wheel/four-wheel drive systems make winter driving easier.

The ability of these systems to divide the vehicle's power among all four tyres provides a real advantage when accelerating on slippery roads. So, whether your vehicle has anti-lock brakes, traction control, a vehicle stability system, four-wheel drive or all-wheel drive, it is your tyres that provide the real traction

Wheel / Steering Geometry

Tracking - is where the front wheels are checked against each other using a laser and then moved until the beam is a mirror of itself on the opposite wheel. However, you need to ask yourself this question, what are the wheels actually being aligned to? The answer is not each other; in fact they are not being aligned to anything using tracking. The gauges may show the wheels as being out of alignment; however, what they do not show is which one(s) will need adjusting and there is no way of knowing what the actual angles measure.

They should be aligned to the rear thrust angle; which is the centre point of the vehicles chassis and should always be as close to zero degrees as possible. There is an imaginary line joining both the front and rear wheels together and then a line joining these down the centre. Where the centre line meets the line joining the rear wheels this is the thrust angle and it shows where all four wheels sit in relation to each other.
 
Geometry - the direction and angle at which tyres are set are both important. When a vehicle is measured on a geometry machine each wheel can be independently aligned to the thrust angle with the help of viewing the angles on a computer screen. This is done via separate panels being positioned on each wheel, which are then linked to the computer via lasers. It does not matter if the car only has adjustable front/rear toe, camber, caster or all three. If the rear suspension is adjustable in some form, then geometry check is a must, nothing else will suffice.

Tyre Sidewalls

The sidewall forms a bridge between the tread and plies. Largely made with cross-linked polymers but reinforced with fabric or steel cords that provide for strength and flexibility. The sidewall transmits the torque applied by the drive axle to the tread in order to create traction. The sidewall, in conjunction with the air inflation, also supports the load of the vehicle.

Most tyres will lose pressure over time and they should be checked on a regular basis, it is also a good idea to check the tyre’s condition especially the sidewalls. A tyres sidewall absorbs road variations by flexing and following the contours of the road, sudden failures will usually occur while travelling at high speed on imperfect roads. Small cracks can open rapidly, releasing the tire's air pressure in a severe blow-out with no warning whatsoever. These cracks can lead to a sudden fracture severe enough to separate the tyre from the rim with catastrophic results.

Tyre Inflation Pressure

A recent survey by the National Highway Traffic Safety Administration reported that 27 percent of cars and 32 percent of vans, pickups and SUV's had at least one tyre that was under inflated. Eight percent of light trucks and 3 percent of cars had all four tyres under inflated.

Having the correct pressures in your tyres is essential for safety and efficiency. Under-inflated tyres can be dangerous; running 30 per cent below the recommended pressures gives a sharp increase in the risk of aquaplaning on wet roads. Low pressure also affects the car’s handling and reduces cornering ability, and can cause a build-up of excess heat that can permanently weaken the tyre’s structure, possibly causing it to fail.

This survey estimates low tyre pressure kills as many as 79 people a year with as many as 10,635 people at year injured. Under inflated tyres also wear out more quickly and reduce fuel efficiency.

Tyre pressure should be checked on a regular basis; don't fill the tire to the maximum pressure rating on the tire sidewall. This figure does not take into account a specific vehicle's needs but rather what the tire is capable of holding under max load. The door placard is the place you want to get your air pressure specs. You can of course adjust this plus or minus a few pounds (3-5 PSI) depending on tire, load and handling. The correct pressure is important both for safety and for a long tyre life. Check tyre pressures (including the spare tyre) monthly, and before any long trip. Tyre pressures should be checked cold (tyres not having run for at least 2 hours, or run for less than 2 miles at low speed).
                                               
Air pressure gauge

Check tyre pressures regularly (once every two or three weeks) check the pressure before you drive to ensure that the tyre (and the air inside it) is cold, hot tyres will read a lower pressure and you may over inflate tyre, which could cause a blow-out. Tyres inflated to the correct pressure (see vehicle handbook) improve driving safety, vehicle handling characteristics, fuel economy and the life span of the tyre.

If tyre pressures are checked hot, add 4 to 5 psi to the recommended pressures, many people are not aware of the tyre pressure fluctuation due to ambient temperature.

The tyre pressure tends to fluctuate approximately one degree for every ten degrees of ambient temperature change (a tyre inflated to 35 lbs. on a hot August day may well be 10 lbs. under pressure on a cold January day) even brand new premium tyres will lose a 1-2 lbs. in a month. Inflation using nitrogen does not dispense with the need to frequently check tyre pressures.

Information on the recommended tyre pressures can be found in the vehicle documentation, and often on a sticker fixed to the vehicle, for example on the door jamb or on the fuel filler cap.
In case of unusual pressure loss, have the internal and external condition of the tyre checked, as well as the condition of the wheel and valve. Correct inflation pressure results in safety, higher mileage / longer tyre life and optimum fuel consumption. Incorrect inflation pressure can cause (-14 psi) rapid tyre deflation, (-21 psi) handling and grip deteriorates and also increases braking distance in the wet by up to 30 feet.

Run -Flat Tyre

Most motorists will, at one time or another, suffer the inconvenience of a puncture. This will involve jacking up the vehicle, emptying the boot, removing the spare wheel and changing the damaged wheel over. It is at this point that the motorist realises that punctures usually occur when the boot is full of shopping or when it is raining!

There are inherent dangers associated with changing a wheel at the roadside, particularly if the puncture occurs on a motorway where the work has to be carried out on the hard shoulder.
Disabled or particularly vulnerable motorists need to avoid the risk of being stranded in areas of greater risk such as when travelling alone through city centres late at night.

Whilst a puncture is usually more of an inconvenience and unwanted expense, the dangers involved with a tyre failure at high speed are far more serious. The greatest danger being loss of control of the vehicle, which can occur when the sidewall of the tyre, which is usually kept secure against the rim by the internal air pressure, becomes separated from the rim flange and drops into the well of the wheel. As soon as the beads are disconnected from the rim flange, loss of steering control will occur.

The main advantage of which is to be able to continue to work at pressures which would render an ordinary tyre unusable. The tyre utilizes self-supporting technology, this is mainly achieved by the tyres having much thicker sidewalls which will continue to hold the weight of the car even when the air pressure inside drops. This type of tyre is still able to function even when there is zero pressure in the tyre. It is essential when using a Run Flat tyre that it is operated in conjunction with a tyre pressure monitoring system.

Early run-flats earned a reputation for being noisy and uncomfortable, thanks to their stiff sidewalls, but constant research and development has reduced this drastically,

When a tyre is punctured, or the pressure drops below a predetermined level, the driver is alerted by a tyre pressure monitoring system in the car. The vehicle handbook will give precise guidance but generally the car should not be driven above 50mph or for more than 50 to 100 miles before the tyre must be repaired or replaced. The further it is driven, the less likely it is to be repaired as the increased weight on the tyre sides could damage it inside.

The pressure is monitored in a variety of ways depending upon the vehicle manufacturer. Many systems have the sensor on the valve inside the tyre so any damage to this will necessitate a replacement valve, sometimes at considerable cost. After a loss of pressure, the rims should be inspected to ensure they haven’t been damaged. Damaged or deformed rims should always be replaced prior to mounting a new Run-Flat tyre.

TYRE SPEED SYMBOL
TYRE SPEED RATING
S
180 km/h or 112 mph
T
190 km/h or 118 mph
U
200 km/h or 125 mph
H
210 km/h or 130 mph
V
240 km/h or 149 mph
W(ZR)
270 km/h or 168 mph
Y(ZR)
300 km/h or 186 mph
ZR
Above 240 km/h or 149 mph

Balance and Rotation

Correct tyre / wheel balance will have a positive influence on the vehicle handling and safety. Have them balanced by competent technician using quality equipment. Rotate vehicle tyres every 6,000 – 8,000 miles, this will ensure even wear and enable any defects / problems to be spotted early on and rectified before they become serious. (Unidirectional and low profile tyres / wheels have special requirements for rotation, check with the vehicle handbook or the manufacturer.

Wheel Weight Removal

Use some dental floss tripled over to remove the wheel weights; and then use 3M Citrus Cleaner Adhesive Remover Spray to remove any adhesive residue.

Tread Depth

 A new tyre has a tread depth of between 5/16-inches (8mm) - 7/16-inches (10mm) The tyre has layers of different rubber harness characteristics; the softer rubber composition is closest to the rim and the harder rubber away from it. As the tyre wears down closer to the softer rubber, tyre punctures become more prevalent, especially when the tyre depth reaches > 4/32-inch or less.
Checking the tyres tread depth could avoid you being stranded with a flat tyre or worse. Purchase a tyre depth gauge and check at the same time as you check the tyres air pressures.

Measuring Tire Tread Depth with a Coin

U.S. coins can be substituted for a tire tread depth gauge as tyres wear to the critical final few 32nds of an inch of their remaining tread depth.

·         Place a penny into several tread grooves across the tire. If part of Lincoln's head is always covered by the tread, you have more than 2/32-inch of tread depth remaining. According to most states' laws, tyres are legally worn out when they have worn down to 2/32" of remaining tread depth.
·         Place a quarter into several tread grooves across the tire. If part of Washington's head is always covered by the tread, you have more than 4/32 - inch of tread depth remaining.

·         Place a penny into several tread grooves across the tire. If the top of the Lincoln Memorial is always covered by the tread, you have more than 6/32 - inch of tread depth remaining.
Once you have determined the approximate remaining tread depth in the first location, you can complete your measurement of each tire by placing the coin into additional locations at least 15 inches apart around the tire's central circumferential groove, as well as in its inner and outer grooves. This will help detect uneven wear caused by mechanical or service conditions.

Tyre Protection

Something that Mr. Goodyear discovered by accident, greatly improves wear resistance, and coincidentally, wet traction, it does not make the rubber harder or softer. The polymerization of butyl rubber changes its wear rate and traction, carbon black is the most important feature in traction.
There are two main degrading agents that attack tyres and rubber trim; UV radiation and ozone. Both of these attack the long hydrocarbon chains of the rubber and, by breaking these bonds, shorten the molecules with resulting loss of elasticity
.
Antiozonant
 [: a chemical compound that prevents or slows down the degradation of material caused by ozone gas in the air (ozone cracking)] [1]
Also known as anti-ozonant, they are used as additives to plastics and rubber, especially in tyre manufacturing.
If you were to see rubber going into a tyre factory, it would be grey, not black. Untreated tyres would have a very short life if they weren't protected against the elements and the environment, so amongst other ingredients, Carbon Black is added during the manufacturing process.

a)        Carbon Black- protects the tyre against ultra violet radiation (UV) by absorbing and converting it into heat so it can be diffused safely. But the Carbon Black has a limited life-span because, as it does its job, it diminishes itself. As carbon black loses the ability to do its job, it turns gray. This is why rubber greys as it ages. When it is no longer there to protect the tyre, the original grey rubber colour starts to reappear.
b)       Antiozonants- along with carbon black, the tyre manufacturer mixes in antiozonant and other protective ingredients to repel ozone from the rubber. These waxes and polymers migrate through the tyre at a molecular level to form a barrier against harmful ozone. As the tyres move (with the car being driven) the rubber flexes and heats up, allowing tiny amounts of the wax to surface. When a vehicle is not being driven (i.e. classic show cars, winter storage, etc.) then without this action and the rubber can easily dry out and rot.
c)        Blooming - after the antiozonant works its way to the outside of the tyre and is exposed to the ozone in the air, it oxidizes and turns brown. The technical term for this effect is blooming. Many chemical compounds, especially solvents, react vigorously at ambient temperatures as the oxidizing process takes place between water and the tyre polymer-binding agents. Water tends to wash away the natural oils and micro-waxes that help to maintain the tyres flexibility
d)       Solvents - Michelin, Bridgestone, Firestone and most other tyre companies advise against the use of Dimethyl solvent tyre dressings (non water- based) because they leach the rubber additives to the tyre surface, which then removes the elasticity from vinyl, rubber and paint; causing them to evaporate out of the substrate and could result in premature drying and cracking, leaving behind a dry inflexible surface. Using solvents will negatively impact durability and void any warranty given

Tyre Cleaning
The slightly porous nature of rubber (however this varies according to the polymers used) attracts oils, dirt, brake dust and road grime. For any type of protection to work efficiently on rubber it must be able to adhere to the surface. First remove any brake dust, blooming, road tar, grease and grime, silicone and oxidized rubber from the surface to properly clean it.

The key to tyre dressing durability is deep cleaning the tyre, spray or apply your cleaner allow to soak in for a minute or two and then scrub with a fairly stiff tyre brush, once clean you should be able to take an old white dry terry towel and rub the tyre surface, it should be almost pristine (if not repeat). Tyre cleaner needs to be strong enough to tackle a heavy build-up of tyre dressings, silicone and road grime, but not damage wheel coatings.

A quality citrus-based cleaner (P21S® Total Auto Wash) should clean the tyres down to the original rubber surface, this is especially important when you apply a new dressing, as dressings won't adhere to, or create the right shine on dirty rubber or silicone residue. This tyre cleaner is a strong concentrate; spray-and-rinse, without scrubbing, if you are starting on an old, neglected surface, use a fairly stiff tyre brush for the first application and a spray & rinse at least 3-4 times a year

          Alternative products – Optimum™ Polymer Technologies - Power Clean (diluted 3:1: to 5:1)
Griot's Garage has two excellent products for cleaning rubber. Griot's Garage Rubber Cleaner is for regular cleanings; like a car wash for your tires, cleans rubber tires, trim, and hoses to prepare them for a coat of protectant, it will also removes the white mould release from new tyres. Rubber dressings bond better with clean rubber. For more serious cleaning, there’s our

Griot's Garage Rubber Prep is an intense cleaner for heavily soiled rubber tires, trim, mouldings, seals, and hoses, which strips away silicones, sealants, waxes, oils and greases to properly prepare the rubber This gel rubber cleaner removes old dressings and road grime to prepare the surface for a coat of rubber dressing by getting down to the bare tyre rubber.

Finish tyre cleaning by using a micro fibre towel, the micro barbs in its nap will remove any leftover dirt / debris. Micro fibre came about by combining two DuPont inventions: hydrophobic Polyester (a scrubbing fibre) which also gives the material strength and durability and a hydrophilic Polyamide (an absorbing fibre) that is tremendously absorbent and quick drying.

Notes:
1.        Some tyre cleaners contain bleach to brighten whitewalls but bleach can turn the carbon black in tyres a dull grey colour
2.        Bleche-Wite® Whitewall Cleaner- contains Butyl Cellosolve (2-butoxyethanol) Sodium Met silicate and Sodium Hydroxide, which are base (alkaline pH 13, none of which are particularly paint, rubber or human friendly. It will stain / etch clear coat painted wheels and zinc rotors as well as drying out tyres
3.        Amazing Roll Off and  Purple Power all contain Butyl Cellosolve (2-butoxyethanol) Sodium Met silicate and Sodium Hydroxide, which are acidic, none of which are particularly paint, rubber or environmentally friendly. It may stain / etch clear coat painted wheel surfaces and zinc rotors as well as drying out tyres
Tyre Dressings

A rubber cleaner (Menzerna Wheel Surface and Tyre Cleaner or 3M Tyre & Wheel Cleaner -39036) will remove old dressing, any dead rubber and properly prepare your tyre for the application of a protective product. The porous nature of rubber and polymers attracts dirt, dust, and brake dust and road grime.

As every Concours d’élégance participant knows, dull or weathered tyres spoil the look of an otherwise immaculate vehicle. It is of paramount importance to provide ultra violet (UV) protection for tyres.  Optimum Opti-Bond Tire Gel provides a matte sheen, even diluted 1:1 with distilled water it provides unmatched durability. Matte black tyres with a natural sheen are quite simply the final touch to an otherwise perfectly prepared vehicle.

Detailing relies on the correct preparation procedures and the correct methodology to obtain pristine results. For any tyre protect ant to work well on rubber it must be applied to a clean surface.
DO NOT USE tyre dressing on motorcycles, bicycles, or other two-wheeled vehicles tyres or seats avoid spraying onto brake rotors, brake drums or brake pedals.

CarPro PERL Coat - is a durable, water based protective coating that that contains UV protection and is designed to be used on all exterior rubber and vinyl, including tyres. For a durable (up to three months) low glass, natural look, it can be diluted depending on the desired look and the surface being treated. Recommend dilution ratios - External plastics 1: 3, Tyres 1:1, Interior vinyl 1:5

Application
·         Pour diluted Perl Coat solution into a spray bottle.
·         Apply to a clean dust / dirt free surface
·         Shake the diluted mixture well before use. Spray on surface from 20cm distance and wipe off with a microfiber towel.
·         PERL Coat can also be applied to tyres and rubber / vinyl trim with a sponge applicator.

Protection Water- based vs. Solvent-based

Petroleum distillates (oils) will remove or break down the protective polymers and waxes in tires the difference between water and solvent based is in the carrier system used. Solvent based products use a hydrocarbon silicone to suspend the product. When you apply it, the solvent evaporates leaving the dressing's active ingredients (silicone oil) behind; this type of silicone leaves a high gloss shine and will repel water longer but it is non-biodegradable. Most high gloss products are based upon (DMS) solvents.

Water-based dressings (usually a milky-white liquid) use a combination of natural oils and polymers to offer a non-greasy, satin finish

Water- based dressings

Pros - fast drying, non-greasy, non-slick finish, matte sheen
Cons- limited durability when exposed to the elements, potential for streaking in rain
For vehicles fitted with ceramic brakes and / or pads; products that contain DMS solvents are not recommended as it can contaminate the pads and render them ineffective

Silicone [: more precisely called polymerized siloxanes or polysiloxanes, silicones are mixed inorganic-organic polymers with the chemical formula [R2SiO] n] [1]
Polydimethylsiloxane (PDMS) belong to a group of polymeric organ silicon compounds, which are commonly referred to as silicones.] CAS number - 63148-62-9 (PDMS) sometimes called Dimethicone, is optically clear, and, in general, is considered to be inert, non-toxic and non-flammable.

a)        Water-based silicone dressings - usually a milky-white liquid that don’t contain petroleum distillate solvents that can harm rubber and/or vinyl over time; water-based dressings use a combination of natural oils and polymers that coat and bond to offer a non-greasy, satin finish

(Zaino Z-16 Perfect Tyre Gloss or Swisswax Pneu) Some of these products also contain ultra violet radiation (UVR) blocking agents to help keep tyres from cracking, fading and hardening. Most, if not all water-based dressings are biodegradable whereas solvent- based silicone is not.

b)       Solvent-based silicone dressings - usually a clear greasy liquid, Dimethalsiloxane (DMS) (paraffinic hydrocarbons) that contain petroleum solvents as a cleaning agent. These penetrating-type silicone oils form a flexible protective shield that prevents penetration of moisture and dirt. Most silicone dressings, although very durable, leave a never-dry high gloss film, they remove the elasticity from vinyl, rubber and paint; causing them to evaporate out of the substrate, leaving behind a dry inflexible surface.

When a solvent-based tyre dressing combines with carbon black it forms a liquid that when slung on the plastic body parts of a lighter colour will irreparably stain the paint

Most high gloss products are based upon DMS silicone oil, the difference between water and solvent based is in the carrier system used. Solvent based products use a hydrocarbon silicone to suspend the product.
When you apply it, the solvent evaporates leaving the dressing's active ingredients (Silicone oil) behind; solvent-based silicone is not environmentally friendly / biodegradable

Many tyre manufacturers (BF Goodrich, Goodyear, Michelin, Pirelli, etc.) have issued technical service bulletins advising against the use of tyre dressings containing Dimethalsiloxane (DMS) a petroleum distillate solvent. This type of solvent will dissolve away the protective waxes and can actually aggressively compromise the sidewall.

In the event of warranty sidewall failure, one of the first things tyre manufacturers look for is evidence of the use of these types of products. When found, this is often the cause for not warranting the tyre’s sidewall failure.

The big three auto companies (Ford, General Motors and Chrysler) have issued advisories or technical bulletins to their dealers to not use heavy petroleum distillate-dimethyl silicone oil dressings for another reason; paint and wheel surface staining. Auto companies have found that it is next to impossible to remove the stains, In some cases, even repainting the part doesn’t' t work as the stain comes back through the new paint, requiring the part to be replaced. Most factory styled wheels are coated with a clear coat type of coating. Some are more porous than others and use of an incorrect dressing may stain them the same as the body parts.

Tire Dressing Overspray (Sling)
As you drive the tyres rotate and the inertia can cause tyre dressing to ‘sling’. Tyre manufacturers use carbon black to protect them against ultra violet radiation. Using a dimethyl solvent-based dressing (usually a clear greasy liquid) emulsifies it, if this contaminated dressing comes in contact with your paint and if it dries it will it will dye / cause a stain; it’s especially noticeable on light coloured and can irreparably stain the paint light colours.

                Remedy- This can be caused by (a) applying the product to an improperly cleaned surface, to which it cannot adhere too. The preparation of the surface is the cause of this problem not the product (b) and / or an excess of product, after the dressing has penetrated remove any excess.  Apply a thin and even coating and then buff surface with a clean dry towel 5-10 minutes later to remove any excess and even out the coating.

                Removal - removing tyre dressing ‘sling’, exhaust carbon or petroleum gas stains from paintwork. Use a Limonene based (citrus) cleaner 3M Citrus Cleaner Adhesive Remover Spray, ValuGuard "N" New Car Prep or paint cleaner P21S Paintwork Cleaner or, Klasse All-In-One, failing this use an abrasive polish / pad.
Unfortunately, the only permanent remedy is to remove the stained paint down to e-coat, primer and base coat, clear coat (BC_CC)

Winter Tyres in the UK

Should we all be using 'cold weather' tyres?

[In many parts of mainland Europe where winter weather conditions are generally more severe and more predictable than in the UK it is common practice, or even a legal requirement, for drivers to keep two sets of wheels and tyres – a set of 'summer' tyres and a set of specialist 'winter' tyres.
Winter tyres use a tread rubber compound (high silicone content) and tread pattern specifically designed to retain flexibility in low temperatures (below +7C) and give good braking/traction performance on snow/ice as well as on wet roads in cold conditions . The sidewall of a winter tyre will be marked with a symbol showing a snowflake or snow-topped mountains.
Winter tyres are not really suited to all year round use though – summer tyres will give better performance when temperatures are higher and roads dry – so two sets of tyres are required if you're going to choose specialist tyres for winter.] Automobile Association, UK



Whitewall Tyres

Nearly all American Classic tyre are whitewalls, so purchasing a high-quality whitewall cleaner is suggested. Never use chemical or bleach cleaners, if you’re having a tough time removing stains from the whitewall with cleaners, S.O.S. or Brillo pads will help and 400-grit sandpaper (sanded with water) can be used as a last resort (do not use an abrasive method like this on a regular basis). Without a doubt, frequent cleaning is best for keeping whitewalls in optimal condition. Here’s a quick rundown of the cleaning process:
1. Pre-soak the tyre
2. Clean off loose debris
3. Apply cleaning agent
4. Scrub with a med stiff brush
5. Rinse
6. Repeat until clean
1.        Use a wet, medium grit 3M™ Flexible Sanding Sponge, or SC Johnson Brillo® Soap Pads, which combine fine steel wool with a powerful pink soap; do not use an abrasive method like this on a regular basis
2.        Wesley’s Bleche-Wite® Whitewall Cleaner - this product doesn’t contain bleach (despite its name) but uses optical brighteners; they're added to make the white wall of a tyre appear brighter and whiter than it really is. These agents absorb ultraviolet light and emit it back as visible blue light.
It is formulated with Butyl Cellosolve (2-butoxyethanol) Sodium Met silicate, which are highly alkaline, none of which are particularly paint, rubber, polymer or human friendly. It will stain and / or etch clear coat painted wheels and zinc rotors as well as drying out tyres and with constant use turn them grey. Be very cautious of overspray

3.         (USA) Antique white wall tyres – Coker Tyres Wide White Whitewall Tire Cleaner

4.        (UK) Race Glaze Whitewall Tyre Cleaner - the dual action formula first cleans the dirt and road film from the tyre, then goes on to penetrate the pores of the white rubber, releasing any ground in dirt or grime. Cleans evenly, removing stains and kerb gouge debris, leaving a bright white satin finish. Just spray, agitate and rinse

Raised White Lettering on Sidewalls
Tuf-Shine Tire Cleaner -  for the entire tire and letters, then you put on their clear coating (Tire Clearcoat) on the white letters first, let it dry, apply a second coat, allow it to dry, and then do the surrounding black part of the tires.

 Spare Wheel
Check the pressure and condition of your spare tyre periodically, if your vehicle has the spare underneath, check its mounting hardware and spray periodically with AMSOIL Heavy Duty Metal Protector.

Also check the cars jack and wheel nut remover and have a drop cloth and a pair of cloves available. If you have after-market wheels be sure you have suitable wheel nuts available for the spare wheel

Tyre Storage

The Tyre Garage lets you to safely store seasonal tyres outside, which frees up extra space in your storage areas. This innovative, new product is made of the same rugged, weatherproof material used for boat covers and awnings. It retains its colour and strength for years of normal exposure to sunlight and rain. It also resists mildew and cleans easily Also great for inside storage, it will cover up that unsightly pile of tyres - TOTL

·         Pack each tyre separately in tyre covers (TireTote) storage bags will work just as well, provided that they are sealed.
·         Store the winter tyres in a cool, dry place. Basements and garages are good storage places, as well as temperature regulated, water proof sheds. If none of these options are available, contact a reputable tyre dealer that offers tyre storage.
·         Stack the tyres flat on their sides, not more than four tyres high. Tyres stacked more than four high are unstable and can tip over.
·         Check the tyre pressure for each set of tyres when it's time to remount the tyres. Consult the manufacturer's instructions for the appropriate tyre pressure

No comments:

Post a Comment