Ask the Expert Question-and-Answer Archive

by Ron Joseph

November, 2005

Airless Spray Gun for Painting Aluminum Boat

Q. I have been a commercial painter for since 1980 and would like to ask you a simple question. I want to paint a aluminum boat I am going to prime with Algrip 545, then final with Imron 5000, there are so many types of tips now for the airless, from ultra fines to tips that would shoot block fillers, could I use a airless sprayer instead of a HVLP?

A. In principle you can use an airless spray gun for painting your aluminum boat, but you will need to be a great painter if you can do the job without incurring runs and sags. I understand your statement concerning fine tips, and other then your technique, I see no reason why the application wouldn't work.

However. I do have a word of caution. Airless spray guns apply very wet coatings since the solvents do not flash off as fast as when air-atomizing spray guns are used. When you apply multiple wet coats of paint, insure that you allow sufficient flash-off time between coats to avoid the problem of solvent entrapment. If much of the solvent cannot evaporate out of the cured paint film you can expect paint peeling all the way down to the aluminum substrate. I'm sure you would not be happy with such a catastrophic paint failure.

Best wishes,

Ron Joseph