Archive for the ‘Technical’ Category

Technical

Without going into War & Peace mode, here is a selection of articles that give an insight into the processes that we use to prepare our customers’ cars to a very high standard.

Please contact us if you require more in-depth information or if you have a technical question that we have not covered.

Deep cleaning your car’s paintwork

When we wax or seal your car (usually every 3-6 months if your car is on one of our Care Plans) we take a great deal of care to ensure that your paintwork is properly cleaned prior to an application of protective wax or sealant.

There are two reasons why we are fussy about our cleaning process.  Firstly we do not want to seal contaminants in, and secondly, wax or sealant does not properly adhere to unclean paint which would minimise the effective lifespan of the product.

Our typical deep cleansing process looks like this:

  • Pre-foam car with snow foam to loosen dirt and grit particles, allow to soak and rinse off.
  • Carefully wash car with a high quality shampoo and lambswool wash mitt.
  • Dry car.
  • Apply solvent de-tarring solution to areas susceptible to tar build up and allow to dwell, remove gently with a very soft cloth and then rinse car.
  • Clay-bar car to remove bonded-on contaminants.
  • Wipe car down with isopropyl alcohol to remove clay-bar lubricant and any stray shampoo residue.
  • Apply paint cleanser to the car and buff off.

Then, when we are 100% happy that your cars paint is clean, we apply a protective wax or sealant.

Please note that with a cheap valet you will often only have the wash part of this process included.  And quite often de-tarring is an extra.

Please keep this in mind when comparing what we do with other valeting companies.

Snowfoam

Snowfoam is a high-cling mousse with very fast acting cleansing ingredients.  It is applied to vehicles prior to washing to remove larger grit particles and most of the road dirt present on the vehicle.

This is a key stage in the cleansing process that helps to prevent swirl marks.

We also use snowfoam as a ‘moisture blanket’ to prevent wheel cleaners from drying out in warmer weather.

Here we show an Aston Martin DB7 where the snowfoam has been dwelling for several minutes.

Clay bar

Ever wondered what all those gritty particles are on your car when you have just washed it?

They are bonded-on contaminants, the typical culprits being tar, tree sap and metal particles from the engines of other cars (they exit via the exhaust system).

No amount of washing will shift them and if left in-situ they will damage your car’s paintwork.

We use a whole variety of clay bars to remove these contaminants, some are harsh and remove bodyshop overspray and others (the ones we use every day) are mild and remove the problems already mentioned.

By keeping the clay warm and soft and using a special spray-on lubricant, the contaminants are safely removed without harming the car.

This piece of clay was used to clean a 2′ square section of Range Rover wing.  The vehicle was 6 months old and is owned by a new customer of ours.

Tar spot removal

Tar spots are both unsightly and, if left on too long, can cause damage to the paintwork of your vehicle.

Wax or sealant provides a good barrier that helps prevent tar spot damage.  Neither will stop tar clinging to the vehicle but the thin buffer layer will certainly minimise any damage.

We use two methods to remove tar spots, both safe and very effective.  The first method is to use a clay-bar to mechanically remove the tar and the second is to use a paint-friendly solvent.  The latter method is preferred as we can spray solvent into areas clay-bars cannot reach.

This Mercedes CLK is shown during and after solvent treatment.

Alloy wheels

Some facts regarding your alloy wheels.

Many car owners are not aware of this and most are very surprised when we explain that alloy wheels are painted.

In the dim and distant past alloy wheels were left ‘naked’ and had a less than perfect finish.  But for many years now they have been finished using exactly the same method as your vehicle’s paintwork.  They are primed, sprayed a suitable colour (there’s a myriad of different silver colours too) and then protected with a clear lacquer coating.

Alloy wheels operate in extreme environments ranging from icy cold under normal running conditions through to extremely high temperatures induced by continuous braking.  They are also heavily exposed to road gritting salt and road surface oil deposits.  Not surprisingly they are prone to damage.

Primary causes of cosmetic wheel damage are:

  • Failure to keep the wheels clean allowing contaminants to bond to the painted surface and eventually causing the lacquer and paint layers to delaminate.
  • Kerbing.
  • Lacquer chipping (allowing salt water under the lacquer layer) by less than gentle tyre fitters.
  • Red hot particles spun off from brake pads (these cause pitting in the wheel surface).
  • Using aggressive acid cleaning products  that harm the lacquer layer (we don’t use acid wheel cleaners).

Whilst we have no control over the kerbing of your car wheels and the conditions they operate in we can offer you advice that will help keep your wheels in the best possible condition.

We recommend that alloy wheels are sealed periodically to protect them from corrosive brake dust etc.  This service is included in all our exterior services with the exception of the Classic exterior valet..

In an ideal world your wheels should be in this condition – Range Rover Sport at >100k miles.

Tailpipes

Not a particularly sexy area of your car but one that can easily detract from your vehicle’s overall appearance.  All of our exterior valets deal with the cleaning of these components. 

Using a 3 stage process that includes dirt & grit removal, de-tarring and corrosion removal we can restore tailpipes to a near new condition unless they have been so badly damaged that they need replacing.

Porsche 911 Carrera before and after photos.

Polish vs wax vs sealants

A simple subject that causes some confusion!   Here’s a quick explantion of the difference between the three.

Polish: uses chemicals or abrasive compounds to remove a small proportion of the vehicles paint.  By removing any dulled or scratched material the vehicles paint will be smoother and more reflective, hence shinier.

Wax: is a naturally occurring product that is applied as a layer on top of your vehicles paint.  It provides protection to the paint from harmful atmospheric pollutants.  It also makes your car more reflective and shinier.

Sealant: the synthetic alternative to natural wax.

Water beading

Always a fascination, water beading on your car’s paintwork has a strangly hypnotic quality.

Surfaces on which water beads are called hydrophobic surfaces.  That is, the water “fears” the surface.  Water tends to bead up on these types of surfaces because it is more strongly attracted to itself (other water molecules) than the surface molecules.

Both wax and sealant will form a hydrophobic surface on a vehicle’s paintwork which promotes the rapid dispersion of water and any contaminants it may contain.  Similarly, water staining of paintwork is minimised.

Beading on a Porsche Boxster S waxed 3 months previously with Swissvax Best of Show Wax.

Paintwork correction

Paintwork correction is the process of eradicating defects from the paintwork of a car. Typical defects include:

  • Swirl marks caused by poor washing techniques.
  • Random scratches.
  • Overspray from poor bodyshop work.
  • Buffer trails caused by poor machine polishing.

Careful machine polishing will remove all of the above defects apart from very deep scratches ie those that have penetrated too far into the paintwork’s clearcoat layer.

Polishing is carried out using one of several types of machine polisher (we have three with very different capabilities) to suit differing situations.  Each machine will have a foam pad attached to it, these are available in a wide variety of construction types, softness and size.  Polish is placed directly onto the pad which is then pressed against the paintwork whilst it rotates/oscillates mimicking a ‘hand polishing’ action albeit at a much faster speed. The polish itself is available in a wide array of cutting (how fast they remove paint) options that cater for all paint types.

Other variables include pad rotation/oscillation speed, transit speed (how fast the polisher is swept across the paint surface) and how many passes are made, the latter being the number of times the polisher passes over the same spot.

Careful examination of the paint surface, plus no small amount of experience, ensures that the right equipment, products and techniques are selected for any given situation.

The object of the polishing process is to minimise defects and to ensure that the paint surface is as smooth (and hence shiny) as possible.

Machine polishing is a labour intensive process and a single body panel can take 1-2 hours to fully correct. Due to the costs involved we only recommend full correction for high-end cars that are not subject to the rigours of daily use.

Our Enhancement Detail is a very cost effective option for cars that are used in real world conditions.

Enhancement Detail »»

Here we have a close up of an Aston Martin Vanquish S Ultimate. When she returned from a visit to a body shop her paintwork was in appalling condition. The before and after shots shown here were indicative of the whole vehicle. Full correction was achieved following two full days of machine polishing.

Scratch removal

Modern paintwork is typically made up of a base coat primer followed by a colour coat and then a clearcoat lacquer.

Scratches that do not penetrate beyond the clearcoat layer can usually be polished out without leaving a trace.  However, it is important to recognise that a sufficient amount of clearcoat must remain in-situ following polishing to protect the colour coat.  A too thin clearcoat layer will result in clearcoat failure which would require a respray to repair.

A rough and ready yardstick as to whether a scratch can be polished out is to run a thumbnail at right angles to the scratch.  If the scratch can be felt, it has probably penetrated beyond the clearcoat layer.

Assuming the scratch can be dealt with we remove as little clearcoat as possible using our machine polishers and abrasive polishes.

To ensure maximum safety we check paint thickness every step of the way using our electronic Paint Thickness Gauge.

Before and after shots of a Mini whose paintwork was scratched during a dealership courtesy valet.

Bird strike damage removal

Bird strikes should be carefully removed with warm water as soon as they are noticed. If necessary soak a cloth in hot water and place it on the deposit for several minutes before removal is attempted, this will soften the material and make it easier to remove. Do not rub as you will scratch the paintwork.

However, should you leave the bird strike on your car we can often remove the stain by machine polishing the affected area.  Please be warned that on occasion the bird lime can burn right through the clearcoat layer whichich will require repainting to repair.

This black Audi A6 had two very large strikes on the bonnet that had badly stained the paintwork.  To top things off the owner had used a household cloth (rough!) and T-cut (not suitable for this type of paint) in an amateur attempt to shift them.  This had made matters much worse as the surrounding area was now heavily dulled!

Shot 1 shows the extent of one of the stains.  Shot 2 shows the affected area masked and ready to machine polish – we use the 2 ‘arrows’ to locate the affected area during the final stages of polishing when removal is almost complete.  Shot 3 shows the stain removed but with some residual cleaning up to complete.  Shot 4 shows the area restored to its former glory.

This vehicle took 1.5 hours to remove the etching.

Paint thickness guage (PTG)

This sophisticated device measures the thickness of the combined paint layers (base/colour/clear) on your car.

Using a non-clearcoated area eg a door shut as a datum we can then calculate the likely thickness of the clearcoat layer on your car.

This enables us to safely polish the vehicle without causing potential clearcoat failure by leaving too thin a layer in-situ.

Here we are checking an RS4 Avant prior to scratch removal.  We calculated around 50 microns of clearcoat on the vehicle and our polishing process removed 3 microns which was way inside safety limits.

Paint chip touch in

On larger jobs, as part of our service, we will glady fill in the occasional chip if you have the right colour paint for your vehicle although we do carry generic black, white & silver on the van.

We will be pleased to quote you to touch in areas of extensive chipping.

Sadly we do know our chipping record – 37 on the nose cone of a tracked black M3.