Painting Steel

[fredrosse]

I need recommendations for painting the steel parts of my steamboat that will be in the water. The boat is trailered, usually only in the water for several hours, then air dried on the way home, sometimes a few days in the water, usually fresh water, but brakish water on occasion. In particular these are steel weldments, can the mill scale stay on? I know sandblasting to near white metal is the best surface preparation, but I don't want to do that. I would prefer air spraying the paints, but I have airless also. What primer and base painting system will be tough enough to the steel paddlewheels? Any guidance is appreciated, especially for paint that is not too hard to find.

I have used Krylon spray paints with good sucess, but that is always with spray cans.

[DetroiTug]

Hi Fred,

For the steel hull we sandblasted and used marine two part marine Interlux primer and then industrial enamel topcoat. It's holding up very well. For the rudder and stack I just painted them with the Benjamin Moore industrial enamel - same as the topcoat on the hull, I did have some flake off the rudder and I just grabbed a brush and touched it up and it's been fine ever since. Automotive and spray can primers will hold moisture, they are like a sponge. I would use either marine two part primer or no primer at all. The marine primer is like a ceramic coating.

-Ron

[johnp]

In our concrete plant all the equipment is painted with an epoxy based paint, very durable. even sandblasting it off is a challenge.

[Chris W]

How about galvanizing? I just had 375# of steel engine beds done and it was $142, which I thought was pretty good. They acid dip them to clean the steel before the hot dip.

[Lopez Mike]

I have it done regularly. 100 pound minimum for $100 in Seattle. If I have a bearing surface or an accurate surface where I don't want any zinc, I go ahead and have them galvanize everything and then remove the zinc with a sponge and Hydrochloric (Muriatic) acid. Or block off the hole and pour the acid in for a while. When it quits boiling, there is no zinc.

Wear a mask and/or have a fan blowing the chlorine fumes away from you. And have a hose and a bucket of water for dipping things to stop the action. Eye protection, of course.

It's not that hard on your hands. You can pick stuff up with acid on it and even dip your hands in but them wash them off right away as soon or before it starts to sting.

It's paintable when you are done. Special primer.

Mike