You’d think that when I mention how critical a good ground is to successful powder coating that I’ve attacked the coater’s integrity or their family. I get this look….one of “of course I know how important ground is”. After all, grounding is described in all powder coating and equipment manuals, as well as taught at all training seminars as one of the most critical aspects of successful powder coating. But what do those writers and educators know? Don’t they understand how costly it is to ensure clean hooks on a regular basis? Don’t they know how much time it takes to pull hooks and replace them?
Sure they do……………..But they should also know that data supports the case that after the second time a hook is used the variability of film build across parts coated increases dramatically. A ground breaking study by Kolene Corporation several years ago highlighted this fact in a dramatic way. The study showed that you can usually get by using a hook a second time before cleaning, but on the third and subsequent uses of an un-cleaned hook the film build variability goes off the charts. This means that paint line operators are “kicking” up the powder output on their guns to make sure no parts get through that are light coated or that metal is seen through the coating. The end result is much higher consumption of powder than if the hooks were cleaned every use or at a maximum of after two uses.
I give talks from time to time on the “Good, Better, and Best of Powder Coating” and my first slide is of a Sears Craftsman Powder Coating gun. Bet you didn’t know they sold powder coating guns, did you? We’ll they do and they’re cheap. And they work…..somewhat. They’ll put powder on a part but they won’t do it effectively or efficiently. But my point is…..powder coating in its primal form doesn’t take much to make it work. This is the bane of the powder coating world we live in. Cheapo equipment and poor practices don’t deter from putting powder on parts. They only make it VERY inefficient. So if you’re okay with simply throwing powder at parts in any way possible and ignore efficiency (and the cost penalty of poor efficiency) then ignore anything to do with the cost of hook stripping. Use your hooks over and over again. Life is good………………………..
Or is it????????
If I’ve heard it once, I’ve heard it a hundred times, “I can’t afford to clean my hooks that often”. My comeback to that is simply…..you can’t afford not to”. The data supports this.
I’ll talk more in future blogs about this subject but I wanted to get this out there to start challenging owners and managers to think about their applied costs which are adversely affected by bad grounds. Of course, there is a whole lot to write about from a safety point of view regarding clean hooks. But more on that in future blogs…….