Painting Cast Iron

Question:

We manufacture water features for fountains, pools and ponds. We are starting a line of cast iron products. Since part of the feature will be submerged, what is the best way to protect a cast iron water feature from rusting? In some cases some of our customers use these products in water containing fish. Also, is a non-toxic-to-fish paint option available? C. W.

Answer:

There are a number of options available to you for painting partially submerged cast iron products. As I understand it, cast iron products could be used in immersion service in both fresh water and sea water as well as other liquids. Typical coating systems for this service would be similar to those used on ship bottoms, offshore drilling platform legs, interiors of water storage tanks, water treatment plants and others. If marine life ispresent in the liquid, anti-fouling coatings are not suitable. These systems would probably consist of an epoxy/polyamide primer topcoated with a water resistant enamel. Among these topcoat materials are epoxies, polyurethanes, polyvinyl chlorides, or chlorinated rubbers. Suppliers of these coatings are listed in the 2004 Products Finishing Directory & Technology Guide.