April 2014: How it’s Made

Electrostatic Painting Process


You can have any color you want… as long as it’s black.

That’s what Henry Ford said about his Model T automobiles. Although not documented, it’s thought that he chose black because it dried faster and helped speed up his invention: The assembly line. Well, thank you Mr. Ford because that’s still a pretty good plan.


A KYB shock & strut manufacturing facility like the one in Franklin, Indiana has many assembly lines. The painting conveyor holds about 3000 parts at once and can clean, paint and dry a shock or strut shell in about an hour.



The process is called e-coating (electrocoat system) and can best be described as a cross between plating and painting. First, the tube is hung upside down and plugged to keep the inside free of any paint. Then each tube is washed, rinsed and dipped in an acid to etch the surface, then rinsed again with a paint emulsion before being dipped through a paint tank. The paint thickness is controlled by applying an electric voltage so that all areas are covered uniformly. A rinse tank removes the residual emulsion and then recycles it back to the paint tank. Then the paint is cured as it passes through a heat chamber.


Yes I know, some say the only thing more exciting than paint drying is watching grass grow. Still, it has to be done and done right. KYB shocks and struts have to pass rigorous environmental testing like salt spray and extreme temperatures to be sure that the paint stays on …and the rust stays off.


image007Painted and ready for the assembly line