PAC tells how... to create a smooth paint finish [Archive] - Bimmerfest - BMW Forums

: PAC tells how... to create a smooth paint finish
03-12-2011, 04:13 PM
Removing Paint Contamination and Create a Smooth Paint Surface.

What is Paint Contamination.

Paint contamination describes any material that attaches itself to the paint and cannot be removed by normal washing methods. Paint contamination most commonly consists of shavings from rail dust, brake dust, and industrial fallout. This affects all paint finishes will cause damage to the paint if left untreated. Paint contamination can be felt as a ďrough or grittyĒ texture on the paintís surface and can appear as tiny rust spots. This contamination can not be removed by normal washing or waxing.

Where does it come from?

There are three major causes of paint contamination.

1) Rail dust- produced from the friction of train wheels against railroad tracks. Over 70% of new vehicles are shipped by rail. Rail dust will often contaminate a new carís finish before it even reaches the dealership. Anytime a vehicle is parked or travels near railroad tracks it is subject to rail dust contamination.

2) Brake dust- particles produced from the friction of brake pads rubbing against the rotor. This metal on metal friction disperes tiny particles of bare metal into the air on the highway where it collects on passing vehicles.

3) Industrial fall out- another, more polite way of saying pollution. Industrial fall out is a by product of our modern industrial age.

Testing for Paint Contamination:

After washing and drying your vehicle, put your hand inside a plastic sandwich bag and lightly run your finger tips over the paintís surface. It should be as smooth as glass. If you carís surface has a rough, gritty, or pebble-like texture, it indicates the presence of paint contamination. In the old days body shops and detailers would restore to using an aggressive paint compound to grind away the contamination. Today, we recommend using a detailerís clay bar. Not only are clay bars easy to use for the enthusiast, they are far safer than grinding away the contamination with a buffer.

Removing Paint Contamination:

There is no wax, natural or synthetic, or any chemical treatment that can prevent or protect against this contamination.

The best solution is Detailerís Clay. This special type of clay, not to be confused with Play-Doo, was developed in Japan. Detailerís Clay safely removes rail dust and industrial fall out. Detailerís Clay can also remove water spots, stains, and overspray from the paint, as well as increase the gloss and reflectivity of a contaminated car. Detailerís Clay is available from different manufacturers and in different grades of aggressiveness.

Professional grade clay bars are aggressive in nature and will quickly cut through the most stubborn contamination, but they are likely to leave behind fine scratching that requires the use of a machine polisher to remove.

Detailerís clay used to be made from a very fine abrasive clay that would shear off the surface contamination. However natural clay, while working great, would age over time and lose itís effectiveness. It could disintegrate if exposed used with a lubricant that had too much solvent.

Blackfire PolyClay II ( is a fully synthetic clay bar that addresses the natural short coming of natural clay. These clay-like bars are made in the U.S.A. of entirely man made polymers. These bars perform all of the functions of traditional clay bars but have a number of advantages:

1) Blackfire PolyClay II does not dry out with age.
2) Blackfire PolyClay II does not decompose with repeated applications.
3) A single non-abrasive grade clay works on most paint conditions yet is still clear coat safe.
4) Blackfire PolyClay II is easier to work with. It pulls, streches, and refolds easier than normal clay.
5) Blackfire PolyClay II will leave almost no residue on the surface making clean up easier.
6) Blackfire PolyClay II is extremely solvent resistant which makes it easier to clean, which in turn makes it last much longer.
7) Blackfire PolyClay II is huge! This 200 gram bar can be cut into 4-6 equally sized pieces, and each piece can be used on multiple cars.

How to use Detailerís Clay Bars:

Clay bars should only be used on a freshly washed and clean surface. Dirt on the surface will cause scratching.

Always use a lubricant such as Blackfire Clay Lubricant ( with a clay bar.

Work on sections about three square feet. Lightly mist the surface with the lubricant. Cut the clay bar to size. A large 200 gram bar like Blackfire PolyClay II can be cut into as many as six equally sized pieces. Store the pieces not in use in a plastic baggy for safe-keeping. Flatten the Detailerís Clay bar piece into a patty and place it in the palm of your hand and rub it across the lubricated surface with moderate pressure. (Hard rubbing is not required).

You should feel a slight grabbing at first. As you rub, the bar will begin to glide smoothly across the paint as it is cleaned. When the clay bar moves freely you are done with that section. Wipe the surface with a clean, soft micro fiber towel and continue in sections until the entire vehicle is complete.

Note: You will likely find the rear of the vehicle, such as the rear bumper, to be the most heavily contaminated since the aerodynamic flow of modern vehicleís tends to stall in the back.

As the clay bar becomes soiled, simply fold the soiled part on itself and mold back into a patty shape. When the bar becomes totally soiled (dark in color) discard it. If you drop your clay bar on the ground you should discard it, even if it looks okay.

Advanced Tip: The problem with folding your clay onto itself is that the contamination is pushed into the center of the clay bar. This will lead to the clay becoming soiled much faster. To take advantage of Poly Clay IIís incredible chemical resistance we developed Blackfire Clay Bar Cleaner and Extender. Simply mist on the contaminated side before folding it over, and rinse in a bucket of water or with a hose. This will remove almost all of the contamination from the clean and greatly increase each the life-cycle of the bar.
After claying, the surface should be as smooth as glass. Remove any remaining smudges with a clean dry towel. Microfiber towels like our Multi-Task Detailing Clothes ( are perfect for removing clay residues. Mist the surface with lubricant if necessary to make the final wipe down easy.

Tech Note: Clay bars will not remove scratches, swirls, or dull-oxidized paint. Normally claying will not restore surface gloss unless the car is heavily contaminated.

Polishing and Finishing:

After claying the surface, you have two options. If the vehicleís paint is in like-new condition (good paint gloss and no swirls), you can finish by applying your favorite wax or paint sealant. If the finish shows any swirls or lacks luster, polish with a swirl remover or finishing polish and then apply a final coat of wax or paint sealant.

Frequency of use:

Blackfire PolyClay II will not remove paint or the clear coat finish. It can be used as often as necessary to keep the surface free of contamination and smooth. Inspect the finish for contamination by feel and clay when needed.

Always apply a protective coat of wax or paint sealant after claying.

03-12-2011, 10:03 PM
good info

bigg fella
03-15-2011, 04:21 PM
Thanks for the great write up!