Ask the Expert Question-and-Answer Archive

by Ron Joseph

September, 2001

Paint That Looks Like Rust

Q. I am working with a facility with a paint emissions problem. They appear to have significant amounts of paint that get carried over into the bake oven, where it drips off in the oven and over time may be at least partially combusted. The regulatory agency here wants to establish this paint combustion as an emissions source. Have you any experience with quantifying such emissions? Can you suggest ways other than changing the hook configuration, slowing the conveyor speed and using fans to blow off paint prior to the oven to eliminate the carry over (they've tried these already)?

A. Thanks for your email. Are you sure that the rust color that you have seen is, in fact, a coating? For many years the steel industry has been selling special steel alloys that are specifically intended to form rust superficially to give a uniform color. The steel is specifically used on guard rails, the siding of buildings, large lamp posts, such as in sports stadiums, etc. The primary intention of the industry has been to provide a finish that does not require maintenance and does not need to be painted.

If you have a different application in mind, please give me more details as I would like to follow up for you.