I am the paint line foreman for our plant. We are using conventional air pressure pots and spray guns, which must be cleaned occasionally. To clean them, we currently run solvent through the lines and spray the dirty solvent into 5-gal containers for reclaiming. I know this is a wasteful process, so I would like information on products that are environmentally compliant for capturing solvents during the paint gun cleaning process. R.F.
You are right, R.F. It is wasteful indeed and is also becoming expensive since solvents cost about $2/gal. It will soon become more expensive if you do not comply with air quality regulations requiring the use of spray gun cleaners. For example, the Pennsylvania Department of Environmental Protection (DEP) has a new regulation requiring the use of enclosed containers for cleaning spray guns. It is presently targeting body shops, but like other regulations it will eventually include all painting operations. Suppliers of spray gun cleaners can be found at www.pfonline.com on the Suppliers page or in the 2001 Products Finishing Directory and Technology Guide (PFD) on page 579 under Spray-Gun Washers.
I am pleased to see that the DEP also recognizes the cost benefits of more efficient painting. By using painting equipment with higher transfer efficiency to apply higher solids paints, it is possible to reduce the hypothetical costs of paints and solvents by as much as $3.50/unit painted from $5.00 to $1.50, a 70% reduction. These calculations are shown in more detail at the end of my chapter, "How Are Coatings Applied?," in the aforementioned PFD.