Hello,
For a while I've used what is called a "clay bar" product to remove surface contaminants from automobile paint finishes. It works very well -- it borders on a miracle product.
How one uses it is to apply a lubricant (such as a soapy solution) to a small section of the car and one slides the clay bar over the wetted surface. Very quickly it smooths the finish out by removing embedded microscopic particles (rail dust, brake dust, tree sap, water deposits, etc.) which ordinary washing/scrubbing does not remove. The results are amazing -- the paint feels as smooth as a baby's behind. :^)
Anyway, the commercial "clay bars" for auto detailing are relatively expensive (like $15 for a 4 oz. bar), and I can't help but think those clay bars are simply some kind of modeling clay with a huge profit margin attached. From some cursory online research, most of the automotive detailing clay bars are made out of natural clay (a couple clay bar products instead use synthetic polymers of some sort.)
One person mentioned trying out inexpensive modeling clay and getting good results:
In the article the author talks about paying a few dollars for a whole pound of clay, which means the clay need not be reused as much. Clay bars get dirty from all the stuff they pick up, so the more it is used the more likely it will scratch. So it's better not to overuse a clay bar, and this only adds to the cost of using them. With the cost of modeling clay so little, one can do one car (or even half a car) and throw the clay away for a fresh piece.
Anyway, using modeling clay intrigues me. However, before rushing out to buy some modeling clay and trying it out myself, I'd like to get feedback from the modeling clay artist community regarding this. Do you believe the commercial automotive "clay bars" simply use some type of commercially-available modeling clay? Or are these truly special, made to "spec" by the clay companies, with nothing comparable sold to the modeling clay community? Of course, the biggest fear is that the particles in many modeling clays are not fine enough and will visibly haze the paint. Is modeling clay also rated by the size/fineness of the clay particles? I do know some auto detailing product companies offer fine and medium "clay bars" -- the medium ones are for tough jobs with the comment that polishing is required afterwards (thus, the medium clay bar must leave a "haze".)
A last point is who are the major manufacturers of modeling clays? I am thinking of contacting them and trying to get feedback -- some might volunteer useful information on this topic.
Your insights will be much appreciated.
Thanks!
Jon Noring
(p.s., another person posted an interesting "recipe" for a clay bar lubricant, thus closing the loop on a "do-it-yourself" clay bar system -- most automotive clay bar products also include a lubricant of some sort: