Ask the Expert Question-and-Answer Archive

by Ron Joseph

April, 2007

Dry Film Thickness (DFT) of Paint of Steel Vessel

Q: How to know which is the correct DFT in order to get the best protection for a steel bottom vessle?

A: Depending on how you intend to use the steel vessel you should start by selecting the coating system, that comprises primer, (intermediate coat) and top coat. Will the bottom of the vessel come into contact with fresh water, sea water, chemicals, etc? How do you intend to prepare the steel surface prior to painting? How do you intend to apply the coating? All of these factors and more affect one's decision as to the type of coating system to be used.

Once you've selected the system, you should consult the paint vendor's technical data sheets for information on dry film thickness.

If the bottom of the vessel will only come into contact with dry soil, a total DFT of 3-4 mils might be adequate. On the other hand, if the vessel will stand on wet soil that is contaminated with chemicals you might need coatings that will give you a total DFT of 10-20 mils.

Regards,

Ron Joseph