You can also use oil based alkyd paint but.
Painting galvanised steel roof.
Certain roofing materials such as terne tin and galvanized steel accept waterborne coatings more readily than oil based coatings.
Painting a galvanized steel panel roof is not all that different from painting other metal objects but you must ensure that the surface is perfectly clean before beginning the application process.
To ensure that you know what kind of metal your roof is made out of and what kind of paint you should use ask a professional roofer to inspect your home.
All you have to do is simply apply the vinegar to a clean rag and then wipe down the galvanized surface.
Galvanized metal roofs are usually painted with acrylic based paint.
Rather this is just a phenomenon that often occurs in galvanized materials due to intermetallic alloying of iron and zinc i understand and is not indicative of the end of the useful life of the galvanizing.
Many metal roofs are made out of galvanized metal which is a type of metal that has been covered with hot zinc in order to protect it from the weather.
However paint on metal roofs often peels or rusts in which case it is time to repaint it.
A paint which will stick well like self etching primer is good and it s necessary if you have real rust.
They are also faster to dry allowing a painter to turn a job around quicker.
Painted metal roofs come with a baked on factory finish and you can re coat these as well as paint bare metal roofing with acrylic latex paint.
If you re attempting to paint siding panels roof flashing or other materials that have seen exposure to the elements a thorough cleaning is necessary to eliminate any organic contaminants from the outer surface.
The secret to painting galvanized steel is white vinegar.
Acrylics are also more flexible than oil and thus handle movement in the metal better.
Get off as much paint or rust as you can.
Using your exterior metal acrylic based paint using the same paint tray that has been emptied of any remaining primer begin to apply the paint with a roller directly onto the galvanized steel roof panels in the same order you applied the primer.
If you have a kitchen then you probably already have this handy solution.
Common household products like comet mineral spirits and chlorine bleach can all be used to prepare galvanized steel for painting.
Be sure to cover the entire surface so that you cannot see any primer left.