Selected Answers

From GIL DOLON of HEMPEL Singapore Pte Ltd on August 18, 2017:
When the type of stainless steel specified for the ...read more When the type of stainless steel specified for the project is determined to be not resistant to  aggressive chemicals, specifically towards acids and chlorides, then painting becomes a viable option. Exposure conditions, as mentioned on some of the replies here, could include under insulation, frequent splashes or where higher risk of constant contact exists.

From OM PRAKASH JAT of Galadari Engineering works on August 13, 2017:
Stainless steels are used because of their corrosi ...read more Stainless steels are used because of their corrosion resistance in a wide variety of service environments, usually without additional coatings. In certain circumstances, however, stainless steel components or structures may require a coated (paint) finish. Examples of this may include company color schemes or logos, environmental blending and compatibility, and general aesthetic requirements. Coating systems for stainless steels must be carefully selected to provide sufficient durability to meet the requirements of the service environment and its associated operating conditions. The combination of surface preparation and formulation of the paint system are key factors in meeting these objectives. In certain environments, localized breakdown of the coating can lead to corrosion, which may be more severe than that experienced with uncoated surfaces and may result in high, localized, rates of attack. In general, stainless steels have flatter and smoother surfaces than carbon steels. This applies particularly to thin, cold-rolled products (sheet and coil) and may adversely affect adhesion between the metal surface and the coating system. Roughening of stainless steel surfaces prior to coating is essential and can usually be achieved by abrasive blasting, light hand abrasion or chemical etching.

From William Slama of International Paint/Ceilcote Products on August 10, 2017:
First, of course, is when the environment or conta ...read more First, of course, is when the environment or contained liquid will attack the stainless (alloy) material. Examples include some solutions that contain high chlorides and fluorides. This occurs when the selected alloy is found, after the fact, not to be resistant to the solution. But, perhaps more frequently, the alloy will be in a solution where other components or vessel walls are coated carbon steel. That makes any fault in the coating on the carbon steel highly anodic and rapid corrosion could result. So the alloy is often coated to remove the large cathodic area.

From ron butt of profile finishing systems on August 7, 2017:
Under insulation service environments ...read more Under insulation service environments