Q. I am the manager of a manufacturing plant where we produce cabinets and enclosures for various industries. I read the interesting article “Co-Cure to the Rescue” by Tim Pennington in the July issue of Products Finishing. We are considering revamping our paint finishing line and were wondering if we could use the autodeposition process he described to paint our products. I.P.
A. As usual, Mr. Pennington hit a home run with his excellent article describing autodeposition. I saw the process in the early 1970s shortly after its conception at the Amchem facility in Ambler, Pa. There is one thing I’ll always remember in the pilot plant version: the coating tank didn’t use pumps for agitation. Instead, it was agitated by a flapper, which moved the liquid similar to a wave pool. There may have been concern at that time that the high action of the pumps would destroy the properties of the emulsion. Amchem’s primary business was metal pretreatment.
Of course, as with any product, there are advantages and disadvantages. One of the disadvantages is that autodeposition is used only on bare steel. For this reason, my company did not pursue it. Most of the electrical equipment and apparatus we manufactured had to meet UL and NEMA standards such as requiring equipment boxes to be galvanized steel.
However, some of the advantages of autodeposition include no need for pretreatment, smaller factory footprint, lower energy costs and mono-bake with certain topcoats.