Detailing Clay

Detailing Clay is used to remove bonded surface contamination that have adhered to the paint and restores a glossy appearance and a smooth surface. Some paint contamination, such as iron oxide from sintered (friction heated) ferrous iron brake or rail dust actually penetrates the paint surface; add moisture and it causes corrosion (rust) of the sub-surface paint and metal, which cannot be removed with detailing clay (See “What will decontamination remove that washing / clay will not?)

Even new cars that have been setting on a car dealerships lot for a few weeks can accumulate contamination that bonds to the paint surface; don't assume a vehicle that looks good is contamination free Regardless of how clean you think your paint is, there are still contaminants stuck on the paint that you need to remove before waxing or polishing your paint. Road film, oil, tar, grease, water spots and other environmental contaminants bond to the paint and glass surfaces and are difficult to remove. Glass and especially the wind shield and rear window on trucks and SUV s are prone to these surface contaminants.

Detailers Clay

Before the advent of detailer’s clay it was a common practice to remove paint-over-spray with a one-sided razor blade and a surface lubricant or by polishing the surface with a compound / polish and a wool pad. Surface contaminates were removed with a polish or by wet-sanding, but these are methods are very invasive and will remove clear coat. 

One of the most prevalent myths concerning detailers clay is proffered by marketing information that states something like this: [clay pulls contamination from your paint] If you think about it, detailers clay requires surface lubrication in order to function correctly; so how do you pull on something that’s  wet and slippery with lubricant. This myth was born from a fear of telling people the truth (often the case with marketing) about its abrasive content. Actually detailing clay is an abrasive paint care system, available in various grades of abrasives, comprising a malleable polymer and micro abrasives

Essentially, detailer’s clay is a malleable applicator that contains suspended abrasive particles, used with a surface lubricant it aquaplanes across the paint surface and removes surface contaminants by abrasion and then encapsulation by the malleable polymer. Detailing clay formulation determines the optimal function of the clay, which is determined by the grade of abrasive used and the density of the malleable polymer. Clay that's designed to remove paint over-spray uses a firm polymer and contains micro abrasives equivalent to an aggressive polishing compound, whereas a fine grade of clay uses a soft polymer and micro abrasives consistent with a finishing polish. 

Most clay makers add colour to identify differing grades of abrasives.

Be cognizant the using a clay bar can actually add minor imperfections in your paint so it's always best to follow up with a polish to remove any clay induced micro-marring. An alternative to using detailer’s clay is a chemical paint cleaner; these don’t leave any surface marring

When you're finished the detailing clay process, you should wash it to remove the lubricant film residue and then go over it with a pre-wax (chemical paint cleaner) to finish cleaning the paint. (See also Acid Rain, Industrial Fallout (IFO) Corrosion, and Decontamination)

Detailer’s clay is made from Polybutene a malleable polymer material; it was originally invented and patented in Japan in 1987. Tadao Kadate is generally acknowledged as the inventor of automotive clay resin for the removal of paint over-spray. First used by Japanese auto manufacturers on vehicle production lines and then auto body repair shops, the technology was passed on to the US market in the late ‘90’s. Detailer's clay is now routinely used by OEM's, professional detailer's, vehicle auctions and body shops as a simple, safe way to remove paint over-spray, tree sap and industrial fallout from both vehicle paint and chrome and glass surfaces

The primary detailing clay patent (U.S. Patent No. 5,727,993) identifies three unique elements (claim 57) used in concert:

“A method of polishing a protrusion or stain from a surface comprising; applying a plastic flexible tool to the surface, the plastic flexible tool comprising a plastic flexible material having mixed therewith an abrasive comprising grains from about 3 to 50 mm in diameter and; applying a force to the plastic flexible tool such that a polishing force per area is applied by the plastic flexible tool to a protrusion or stain on the surface, and such that the amount of force per area applied to the surface is less than the amount of force per area applied to the protrusion or stain.”

Do I need to Clay my Surface?  

Claying is not always necessary. However, chances are if you need to ask that question, your vehicle has never been clayed and you will likely have to take action. To verify if your vehicle is in need of claying conduct the ‘Bag Test’-After washing and drying your vehicle place a plastic sandwich bag over your hand or fingers, gently pass over the surface. Does the surface feel silky smooth or rough and gritty? If you felt roughness and/or grit, your surface is contaminated

Polishing vs. Detailers clay

Although they are both abrasive process they are very different; detailer’s clay removes surface contaminants. Polishing removes surface scratches and levels the surface to provide a reflective surface

Decontamination vs. Detailer’s clay

Paint decontamination systems were developed as a method of removing paint contamination that is embedded in the paint surface; beyond what can be removed by washing or claying alone.

Surface Contaminants

Surface contamination comes from a variety of sources, and can be categorized based the typical size of the particles and what they are made of, they are either organic such as bird excrement, honeydew and bug carcasses or inorganic such as ferrous iron (brake / rail dust) bituminous asphalt, etc . Brake dust residue are sharp fractured metallic particulates that embed themselves in the clear coat along with acidic brake pad adhesive, which adheres to the clear coat

If the paint surface has a rough ‘textured’ feel this  roughness is most probably due to surface bonded contaminants, these contaminants come about due to exposure to  industrial fallout, paint overspray, brake  dust, and etc.. While they usually accumulate slowly over time, it is possible for a single event to cause them. Detailer’s clay and a surface lubricant will generally remove the protruding particle, leaving the particulate below the paint surface to act as a conduit.

Modern clear coat is urethane, which in essence is a thermoplastic, when heated expands and when subjected to low temperatures contracts. Acid is inert until it comes into contact with moisture, clear coat expansion allows liquefied acids to be carried through the paint matrix down to the metal substrate using ferrous iron particulates as a conduit.

Corrosion

One of the   most familiar types of corrosion is ferrous oxide (Fe (OH) ³ red brown rust), generally resulting from atmospheric oxidation of steel.  Its presence actually promotes additional attack by attracting moisture from the air and acting as a catalyst in causing additional corrosion to take place. As a result, rust must be removed from steel surface, if complete control of the corrosive attack is to be realized.

The used of abrasive compounds (polish or detailing clay) is an acceptable clean-up procedures.  However, it should be recognized that in any such use of abrasives, residual rust usually remains in the bottom of small pits and other crevices.  It is practically impossible to remove all corrosion products by abrasive or polishing methods alone.  As a result, once a part has rusted it usually corrodes again more easily than it did the first time.

The only way to completely remove sintered (heat fused) ferrous iron particles and acid contaminants is with a dedicated decontamination system that opens up the paint's pores utilizing an exothermic reaction to release iron particles and acidic residue and neutralizes the caustic compounds. In one step, you can eliminate both the cause and its effects.

Reactivity 

            [: acceleration of a chemical reaction by a catalyst] 

Like any chemical attacking a surface, temperature will dictate reactivity (acceleration of a chemical reaction by a catalyst [moisture and heat]. The more heat and moisture that is present (in the form of high humidity, dew and etc) the more aggressive the acid becomes. 

Then you have; an acid + water +oxygen + ozone all of which forms an acidic oxygen molecule that attaches to the ferrous iron particulates and causes a concave indentation (acid etching) to the paint surface. It should be noted that until this acid is neutralised subsequent moisture and heat will reactivate the acid and allow further damage, as acid requires an alkaline to neutralize it

The Bag Test

 A ‘brand new’ vehicle is at least a month old the day you sign the papers and drive off with it. Most vehicles, once they are produced, sit in a giant parking lot outside the factory for at least one month. When they are ready to be shipped it can take one to two weeks.

If the vehicle is to be imported it may take more time shipping by boat, rail and then by road transporter. Once they arrive at the dealer, it can take up to another two weeks for the dealer to remove shipping items and have it ready for the lot. Finally, it's just a matter of how long it takes for somebody to purchase it. It could be three days, it could be four months. As you can see from the above a ‘brand new’ vehicle is actually three plus months old

Even new cars that have been sitting on a car dealerships lot for a few weeks can accumulate contamination that bonds to the paint surface; it shouldn't be assumed a vehicle that looks good is contamination free. Here’s a simple test that will indicate whether or not you need to clay.

Wash and dry your vehicle, put a plastic sandwich bag over your hand and lightly rub your fingertips over the paint The plastic film between your fingers and the paints surface greatly heightens sensitivity.  If it feels rough or you feel little bumps or protrusions every snag you feel is a surface contaminant that the clay bar can remove but you may not be able to see, especially on white or light colour vehicle surfaces.

Detailing clay has made a huge impact in paint finish care because it removes oxidation and allows the paint to remain healthy, longer. Applying a coating over a paint finish does not stop oxidation; it only slows it down. Using a chemical paint cleaner is better for your paint finish; because they strip away some oxidation and allow the coating to obtain a better hold (anchoring to the micro-fissures of the surface) and lasting longer to retard oxidation.

Application – aquaplaning, also known as hydroplaning is the condition where a layer of water builds up between the surface and the clay, this thin film of lubrication provides a safety barrier that enables the clay to hydroplane across the surface.

In other words, by applying just enough pressure to ensure contact with the surface the clay will aquaplaning on a micro-thin film of lubrication between it and the paint surface removing the (protruding) surface contaminants by abrasion and encapsulation by the malleable clay. Without lubrication the clay will abrade the paint surface much like a dry-sanding block and will produce significant fine surface marring.

Form a 2 or 3-inch disc approximately 1/8- inch thick, the disc should be slightly larger than your fingers and thick enough that friction will not wear a hole through the clay. Your fingers are applying the necessary pressure, so a disc that is too large is serving no useful purpose; a disc slightly wider than your fingers allows the clay to transverse surface contours. 

When you start the clay process you’ll feel resistance as you glide the clay with its lubricant, this is normal, the resistance will lessen as the contaminants are removed, and once there is no more resistance you should move to the next 2 x 2-foot section. Knead the clay so there is a fresh surface, once it picks up abrasive contamination it becomes just like sandpaper. A medium sized vehicle should take approximately 30-45 minutes

Storage - detailer’s clay should be stored in a cool dry place, with a temperature in the range of 50 -75.^oF.  Store your clay in a plastic baggie or a plastic soap travel case. Mist the clay with a Quick Detailer (QD) Wrap each piece in wax paper to stop them sticking together, place in a plastic storage container, and close the lid or seal tightly

When you're finished the detailing clay process, you should wash it to remove the lubricant film residue and then go over it with a pre-wax (chemical paint cleaner) to finish cleaning the paint. Pre-wax cleaners are a combination of light micro abrasives and cleaning solvents. Most of their cleaning ability is provided by the cleaning solvents, not the abrasive, they are so light that you would have to rub for hours to remove swirl marks. (See also Acid Rain, Industrial Fallout (IFO) Corrosion, and Decontamination)

Common Questions

Does detailing clay pull contaminants from a paint surface?

Contrary to popular belief it does not pull the metallic particles from the paint surface, if this were true it would not need for it to be abrasive or use lubrication. The abrasives 'shear' or exfoliate the surface contaminates, the particles i.e. the top of the metallic particle are then encapsulated by the clay, leaving the rest embedded in the paint.

Does detailing clay actually remove contaminates or does it just shave off the top, making the particulates flush with the paint? 

This would depend upon the type of contaminate. The clay bar may not totally remove rail dust, but it will shave off the protruding particles. It will, however, easily remove surface contaminants like tree sap or paint over spray, which is what it was originally formulated to do

Does my paint surface require the application of detailer’s clay?

Is the paint surface showing one or more of the following; coloured or yellow stains, water marks (spots) black metallic coloured flecks, a rough texture, etch marks (concave depression) oxidation, bug or bird excrement.‘Bag Test’ put some Saran wrap or a zip lock bag over your hand and rub it across the finish lightly.

Every snag you feel is a surface contaminant that the clay bar can remove but you may not be able to see, especially on white or light coloured vehicle surfaces.

How often should I use detailer’s clay?

Usually twice yearly is average, but that would depend upon your environment and how you maintain your car see ‘bag test’ above, If you find the need to use detailer’s clay on a regular basis use a mild clay-  Sonus SFX Ultra Fine or Pinnacle Fine Clay

If I’m going to polish the car with an abrasive, do I still need to use detailer’s clay?

Polishing and detailer's clay are very different processes; although they both use abrasives, detailer’s clay is a malleable polymer that encapsulates the contaminants. One good reason to clay before you polish; polishing can result in smoothing and rounding the surface contamination it making it significantly harder to remove later. 

Although a polish / compound will remove the contamination there is a risk is that the abrasive particles will become embedded in the foam pad, which will cause surface scratches / marring by making the foam /polish more abrasive than necessary and may cause deep scratches

How often can detailer’s clay be re-used?

Inspect the clay surface often and fold (knead) clay to present a clean surface to the paint to avoid scratching; when the clay surface becomes really soiled (it becomes more difficult to find a clean surface by kneading, relegate to wheel or glass surfaces and then mufflers/exhaust, and then it’s time for fresh clay.

Do not over use a clay bar; your clay is done when the lubricant starts breaking down the clay and it begins to break up. 

Take a 100 gm bar and divide it into 6-8 pieces (this allows you to drop a piece and not have to throw away the whole bar) A mid size car usually takes around 20-30 grams, once the clay becomes too soiled for paintwork, relegate to glass surfaces, and from there to wheel surfaces and finally discard. (See also Cleaning a Detailer’s Clay)

Will detailer’s clay remove the applied paint film surface protection?

It’s an abrasive product; the wax / sealant protection film is probably less than 0.1 µ (microns) or 0.000 004 inch) thick, clay will remove most of the paint protection product and the abrasives usually cause micro marring of the paint surface.

Like finishing paper or an abrasive pad and polish it isn't selective, it doesn't just cause scratches where there are embedded contaminates or surface scratches, but abrades wherever it comes into contact with the surface.

How long does the process take?

This would be dependent upon many factors, such as how well the car is maintained between detailing clay bar sessions, what type of environment is the vehicle exposed to, how contaminated the vehicle is and of course the size of the vehicle. An SUV is going to take approximately twice as long as a Mini.

A mid-sized vehicle usually around an hour to an hour and a half; I would suggest 1-2 hours is an average time for this process. Ambient temperature will affect its pliability and may affect how long the clay process takes, if it’s cold place clay in warm / hot water before use

If your goal is to remove paint contamination why would you only remove part of it?

Detailer’s clay is an abrasive, contrary to popular belief it doesn't pull the metal particles from the paint surface it shears it, leaving a metal particle that will become a conduit for rust compromising the paint system and leaving surface rust blooms (spots)

While clay and chemical cleaners are useful for cleaning the paint surface they cannot deep clean the pores of the paint, or neutralize rust blooms (‘spots’). This can be accomplished with a chemical cleaning decontamination acid and neutralization system.

 Summary

Don't overuse detailing clay; it is all too often over-prescribed as a cure-all. I think once or twice a year is adequate for most well-detailed cars. I would also suggest an annual decontamination system be used; dependent upon environmental conditions encountered, but especially on light coloured or white vehicles. Choose a pre-wax cleaner with the least amount of cleaning and abrasive capability necessary to get the job done without being harsh on your paint.

Related Articles

1.      “Detailer’s Clay vs. Decontamination” - http://www.autopia.org/forum/guide-detailing/136387-detailer%92s-clay-vs-decontamination.html

2.      “What will decontamination remove that washing / clay will not? “ - http://www.autopia.org/forum/guide-detailing/136545-what-will-decontamination-remove-washing-will-not.html