Alternative Pretreatment

Q. We manufacture small steel storage buildings which are shipped as sections six feet long. We would like to expand our product line to include larger steel buildings whose sections are eight to ten feet long. Because of the size of our processing tanks, we cannot handle larger sections. We now pretreat the sections in an immersion system, and then paint them with a two-coat finish system consisting of an epoxy primer and acrylic enamel. What alternatives pretreatments are available for these sections? T.H.

 

A. Naturally, increasing the size of your tanks to accommodate longer sections is an option, if you have the space. Another option is an in-line spray washer. If these options are not feasible, several alternative metal pretreatments prior to painting are available. Phosphate compounds can be applied using steam or hot water spray equipment. Dried-in-place pretreatments can be applied by wiping, brushing or spraying. Another approach is using a wash primer which is considered a pretreatment.

Perhaps a better alternative in your case is the use of precoated metal, which is used by many firms who manufacture similar products. Precoated metal is available in a variety of gages and widths. After an engineering analysis, you may find that cost savings will result from using these materials. I suggest you contact the National Coil Coaters Association, who will provide you with of information. Their web site is: www.coilcoating.org. Let them do the pretreating and painting.