Ask the Expert Question-and-Answer Archive

by Ron Joseph

November, 2005

Liquid Wet Paint Vs. Powder Coating

Q. I am involved in the building maintenance of this fine City were historical preservation is prime. My question is in the restoration of wrought iron railings, is wet painting (using zinc chromate primer and alkyd gloss enamel)versus powder coating (2.5-3.5 mils dry film) which is more superior for the long run.

A. If you are maintaining already existing handrails you don't have an option to apply powder coatings, unless you take them to a custom coating shop, have them stripped (remove all of the existing paint) and start from scratch. The coating system you mentioned (using zinc chromate primer and alkyd gloss enamel) is OK and might perform reasonably well depending on the environmental conditions.

If you were to compare two wrought iron railings, one painted with the liquid system that you mentioned and one that has been properly powder coated by following all the pretreatment steps, the powder coating would be expected to outperform the alkyd system.

Regards,

Ron Joseph