How do I paint the steel crossbeam on a colorbond fence?

Question

I have a colorbond fence.

If you don't have colorbond in your area, it's painted steel panelling that can be used for fences or roofs. My fence looks like this:

But what you can't see is the back - there is an unpainted steel crossbeam.

I'm thinking about painting the crossbeam. Is there any particular preparation I should undertake with the steel?

I've heard I should sand it. And I should use a spray rather than brush... Does anyone have experience with this?

Answer 1

1. As suggested, use sand paper or steel brush to clear any rusty bit
2. Apply some(not too much) rust remover / preventer - let it dry naturally (30minutes - 2hours?)
3. Paint with steel primer (usually grey)
4. Following the drying time guidelines of the primer apply your top coat of enamel or whatever you want.

Do not flood the steel with rust preventer. Let it dry and wash your hands properly. If the rust remover makes white bulges just remove it with a another tool. Do not touch with your hands to avoid a) acid burn, b) oil residue on steel

We use to do that in South Africa on all gate installations because summers were extremly dry and some winters could be torrential with flash flooding. This method lasts years and years. (It is a method borrowed from the automotive industry - in its simplistic form)

Good luck

Answer 2

I'll also recommend the same things that you have already indicated. Do sand the steel before painting it. If it has any rust or scale on it this must be removed by vigorous wire brushing till all the rust is gone. Spray painting is really the best way to paint steel so you must consider appropriate masking of adjacent areas so over spray does not get on other parts of the fence or driveway.

The best paint for this job will be an enamel paint specifically designed for the job of painting on metal. For a relatively small job, like this one seems to be, I would simply recommend that you use the spray can type that you can purchase at the home store or hardware store. Do use multiple light coats of paint to get a nice finish without problems with the paint running or dripping. The only drawback with spray cans is the limited range of colors available.

One last thing you may want to consider is the possibility to temporarily remove the steel cross beam from the gate and paint it separately so that you can get it painted from all sides. Then re-install it and go back and touch up the fasteners with a spritz of the spray paint.