Outdoor Painting

Prepare Galvanized Steel for Painting

If you are having steel railings or gates fitted (or if you are fitting your own), it is a very good idea to pay a little extra to get the steel galvanized before it is delivered. A galvanized coating is probably the best and most cost-effective way of helping to ensure that your external steelwork remains in great condition for years to come. Not only that, by having your steel galvanized, you will save yourself many hours of painting and treating rust over the years as the maintenance needed on galvanised steel is much less.

Galvanization is the process of coating metal with zinc, sealing it and slowing down the process of water penetrating the metal. Products such as gates and railings are galvanized by dipping them in a bath of molten zinc, which is them left to dry. This process can result in sharp drips and spikes forming when the steel is hung to dry. Most of these drips should be filed down before the steelwork is delivered to you, but it is worth checking to make sure, particularly underneath the handrail.

Weathering Galvanized Steel

The main problem with galvanized steel is that, initially at least, it doesn’t take a coat of paint very well. The easiest way to solve this problem is to leave the galvanized to “weather” for four to six months. The effects of wind and weather will dull the coating of zinc and create a key for the paint. After six months, rub the steel down with fine abrasive paper, make sure it is clean, prime it and then paint it with good quality exterior paint.

Treating Galvanized Steel

If you don’t want to wait all that time with unpainted steelwork, you will need to recreate the effect of weathering yourself. This means painting the steel with a water-based alkaline cleanser to slightly soften the zinc coating, and then creating a key with abrasive paper. Alkaline cleanser can be bought from DIY stores and builders merchants.

Paint the alkaline cleanser onto the galvanized steel using an old, clean paintbrush and then use abrasive paper suitable for use on metal to create a key for the paint. Wipe down the steel with a clean cloth to remove any remaining alkaline solution, as well as any dust and dirt.

Paint the steelwork with a good metal primer (this would have been something like red lead paint, but nowadays lead-free paint has replaced this) and allow it to dry fully. Your galvanized steelwork is now ready to be painted in the topcoat of your choice.