Cleaning up with Clay
Hype or help for automotive paint?
August 1998

Clay itself isn’t new—it’s one of the most common compounds on earth, and has been around for well over four billion years. However, it is fairly new to the auto body field, and clay products for use on automotive paint have been increasingly promoted over the past few years. ABRN takes a closer look at this new product to sort out the marketing hype from the practical help.

What’s in a Clay Bar?
Clay bars are composed of fine clay particles of a relatively uniform size in a soft, malleable medium that allows the bar to be formed and kneaded like modeling clay. Color pigments are commonly added to make the bar look better and to identify bars of differing coarseness, or grit.

How Is It Used?
Before a clay bar is used on a vehicle, it should be thoroughly cleaned and dried to remove any loose dirt. Direct sunlight should not fall on the surface, and it’s best if the surface is relatively cool to prevent rapid evaporation of the clay lubricant.

A water-based lubricant is sprayed on a small area and the bar is rubbed back and forth over the painted surface with light to medium pressure. If the fluid begins to dry up, you’ll need to spray more on. The bars are fairly sticky, and can’t be used dry. After a few strokes, rub your hand over the area to feel if the surface contamination was removed. Just continue with the rubbing until all contamination appears to be gone. Clean and visually inspect the area before moving on to clay the next spot.

Check frequently to make sure hard particles have not become embedded in the clay. When they are found, pick them off or pinch and remove the surrounding clay if needed. It’s good practice to occasionally knead and reform the bar so that a fresh portion of the bar contacts the paint. If the bar is dropped on the ground, thoroughly clean and inspect the side that hit the ground. Discard the bar if it becomes impregnated with sand or other hard particles.

Care and Storage
Don’t use lubricating fluids that contain strong detergents or soaps—they can break down the compounds that hold the bar together, which will greatly reduce the bar’s useful life. After use, AutoMagic recommends spraying the inside of the plastic storage container with the lubricating fluid before inserting the bar. Make sure the plastic case is closed tightly and, if possible, store it in a relatively cool location.

The Hype
"Contains No Abrasives" is found on the literature or packaging of some clay products. We all know that’s stretching the truth. In fact, the clay product patent claims I’ve read clearly state that the product contains abrasives. However, I’m inclined to give the marketing people a little slack in this area. The main reason they’re taking liberty with the phrase "Contains No Abrasives" is understandable: the general public thinks "abrasive" refers only to rough, aggressive materials. If a clay bar displayed at K-Mart said "Contains Abrasives," it’s a safe bet many people would avoid buying it out of fear that the clay could damage or scratch their paint.

The abrasives in most automotive clay products, and certainly in the retail-distributed clay products, are so fine that people will not see visible scratches when they are used, and the gloss of most painted surfaces will not be reduced. In that sense, clay products are not abrasive, at least in the public’s understanding of the term. However, you and I know clay products do contain abrasives.

The Help
Clay products have a number of advantages in the removal of surface contamination from paint. First, they are nearly foolproof. Even in the hands of a lay person or first-time user, it is difficult to do any damage to paint using a clay product. Sure, if someone ignores the directions and continues to use it after dropping it in the sand, or if sharp particles get embedded in the contact surface of the clay, scratches can result. But compared to sanding, buffing, polishing or use of strong alkaline or acidic products, clay is as safe as a product can be. And it’s relatively inexpensive compared to the alternatives.

Rail Dust. In the Paint Shop section of ABRN’s June 1998 issue, it was pointed out that clay is now the method specified by Chrysler USA for removal of rail dust and similar surface contamination. One of the primary reasons for recommending clay is that strong chemicals, such as oxalic acid, can cause damage if they accidentally get onto the finishes of some plastic and metal trim parts. General Motors also recommends use of clay for removal of minor rail dust contamination.

Brake dust, which is particularly common on painted rear bumpers and adjoining surfaces, is another metallic surface contaminant that can be removed safely and effectively using a clay product.

Overspray. Removal of overspray is a chore every shop has to deal with from time to time, and this is an area in which clay excels. Again, the use of clay is nearly foolproof, which means this job can be done by less experienced personnel in the shop. If the overspray is particularly heavy or intractable, be aware that AutoMagic makes a coarser bar—which is colored red—for this problem. However, because the red bar is coarser, polishing the surface is recommended after the overspray is removed.

Reconditioning used cars. After a couple of years on the road, contamination can build up on a vehicle’s paint. Water spots, stubborn dirt, salt deposits, insects and bird droppings are other examples of common contaminants that can be removed by clay products. Thorough removal of such contaminants before waxing is recommended by most quality-conscious detailers and reconditioning centers, and clay products are proving fast, effective and safe for this operation. This has not been overlooked by car manufacturers. Cleaning the paint with clay is now part of Ford’s reconditioning process on its Extra Step off-lease vehicles, and Toyota specifies that its certified used cars be clayed prior to waxing.

Retail Products and TV Ads
Body shop personnel need to know about clay if for no other reason than their customers will be hearing of it and may ask questions. The AutoWax Company has begun nationwide TV advertising of its retail clay package, named ClayMagic. You may already have seen the 30-second spots which use colorful animation to illustrate how clay can remove contamination from a vehicle’s surface. The ClayMagic box contains a blue-colored clay bar (same formulation as the PBE blue bar, but smaller in size) and a 12-oz. bottle of BodyShine clay lubricant. NOTE: Auto Wax cautions technicians that the BodyShine lubricant in the retail kit contains silicones, and therefore is not recommended for shop use. The company’s Lubri-Shine clay lubricant marketed through PBE distribution does not contain silicones, so surfaces are paintable after use. The retail kit also contains a 4-oz. bottle of Wet Wax and a sponge applicator as a promotional bonus.

Hands-On Demonstrations
The ClayMagic retail kit contains a thin, clear glove to show consumers the "before-and-after" difference clay makes. When the glove is slid over a painted surface, every tiny particle embedded on the finish is easily felt. After the surface is clayed, the same glove slides smoothly over the surface. It’s a great tactile demonstration, and the glove increases the sensitivity of the hand in feeling gritty particles on a painted surface.

Product Choices
Clay bars are available in different levels of coarseness. For example, the blue-colored ClayMagic bar is described as "fine grade," and the red-colored ClayMagic bar is described as "medium grade." Only the fine-grade blue bar is distributed to retail customers by ClayMagic, but both red and blue bars are available to body shops through PBE distribution. As mentioned earlier, after using the medium-grade red bar, the surface should be polished.

Other manufacturers make clay bars that differ in ways other than the coarseness of the abrasive particles. Some are noticeably softer and more pliable, and others are harder or more stiff to suit the user’s preference.

Clay is not just a gimmick: it has proven to be a fast, easy and relatively foolproof method for removing surface contamination from a vehicle’s finish. If your shop has to deal with removal of rail dust or other surface contamination, removal of overspray, reconditioning of used cars or detailing of weathered finishes, step up to the bar for some relief.