Surface prep is the issue, sand and clean thoroughly. Dry thoroughly. Any moisture will bubble, even that which you can`t see, such as painting in a humid environment. Prime with a quality primer. Paint with a quality metal paint. Sand with a 600-800 grit paper and clean thoroughly. Seal out rust with a clear top coat.
By
02/17/2009
It may be grease or oil on the bench that is causing this problem. Sand, use a degreaser and then let dry before painting.
By tru (Guest Post)
02/17/2009
To get paint to stick to metal, you have to clean it first, then apply vinegar and let dry; followed by painting. I did this on an outdoor shed about 8 years ago and it still looks good.
By
02/16/2009
Did you sand and prime the bench? How did you prepare it for the paint? What kind of paint are you using?