A gun or guns operating at a specific output and position will provide coating thickness within a certain range. If the equipment is used the same each time and is properly maintained, the film build can be predicted within an acceptable range for many coaters. Some coaters use more sophisticated methods, such as film gages, to meter the output of powder and better control the film build. Although these gages are not inexpensive, they can be extremely valuable for controlling film thickness.
In the February issue, I supplied some statistics on powder coating sales taken from the U.S. Census Bureau. A reader contacted us and pointed out that my numbers for the dollar value of powder sold were correct but the reported number of pounds of powder sold did not make sense.
It was 6:30 p.m. when I left the plant. We had been working since 7 a.m. to finalize the details of a proposed new base-coat/clear-coat system and agree on a timetable and price. My cell phone had been ringing just about every 20 minutes all day long. My client's blackberry was in almost constant use.
One of the first questions that we often hear when we greet a friend or a business associate is "How's Business?" It is an easy question with which to start a conversation and we are truly interested in how our associates are doing. But the past few years have put more importance on the subject. Let's face it, the answer since the year 2000 has not always been positive. For some of us it has been just plain awful. And for some others it has been the end of business as they knew it. So here it is: How is business?
I receive hundreds of calls and e-mails asking for sources of information or advice on how to do things. Everyone needs information and training to sustain their business. The most common inquiries right now are related to new ideas for part pretreatment (fewer stages, lower heat, less chemical use), powder coating on plastics, how to build an oven and sources for training. Different answers apply depending on the exact nature of the question, but I always try to give directions on where to find the needed information.
It is an impressive thing to see a very large job shop coater running high volume, high quality products on a three-shift basis and delivering finished product within one week of the customer order.
We have an automatic powder system with 16 corona guns that are used to coat luminaries and fluorescent lights. Because of some Faraday problems in our parts, we decided to place a manual tribo gun after the corona guns. Now, when the operator uses the tribo, all the powder is repelling and removing from the edges of the part. This is totally the opposite of what we wanted. We believe it might be caused by the effect of the corona guns. What are we doing wrong?
More than 40 years ago, while many of us where still in school, a brilliant man in Europe named Ir. Pieter Gillis de Lange was working to come up with a new coating material that would radically reduce VOCs compared to traditional solvent-based coatings.
We coat a variety of parts with different metal gauges from 18-gauge up to very heavy steel plate. Some of our parts that have to be coated include very light gauge stock and very heavy stock in the same assembly.
Recently, I spent eight straight days in a liquid paint facility working to find the cause of severe craters in the clear coat. The work started at 6 a.m. and continued through the dinner hour. Testing, meetings, analysis and speculation comprised the day - and tended to interrupt our sleep as well.
