Painting galvanized steel is a simple enough job but it does require some specific tools and materials. Galvanized steel also requires special surface treatments before painting. Galvanized steel is less prone to rust since it has a special zinc coating which needs to be thoroughly cleaned and roughened so that the primer paint will adhere to it properly. If the paint job is carried out correctly with all of the necessary preparations, it should last many years without any noticeable corrosion.
Step 1 – Wash the Surface
Before applying the primer, the galvanized steel surface needs to be thoroughly washed down using hot, soapy water. It should then be properly rinsed and allowed several hours to become completely dry. When this is dry, mix a solution of water and ammonia, using about two percent of the ammonia. Rinse the steel surface with this solution thoroughly, allowing it to dry afterwards.
Step 2 – Sand Down the Surface
Using sandpaper, preferably 240 grit, sand down the entire surface. You should remove any obstructions such as handles or other parts before proceeding. Every area of the surface needs to be properly covered by the sandpaper. Try to cover every crevice in the surface. When you have sanded the galvanized steel, wipe over the whole surface using tack cloths.
You can find these in any hardware store, normally accompanying the paints and primers. The tack cloth helps to remove any splinters or dust caused by the sanding process thanks to its sticky surface. When you have treated the entire surface in this manner, you will then be ready to apply the primer to the galvanized steel.
Step 3 – Apply the Metal Primer
Before applying the primer, refer to any specific directions on the particular product that you have purchased. Applying the primer will often by done by spraying it onto the surface which makes the job quicker and easier. Be sure to cover the whole surface evenly. The best method to use is to work from the top to the bottom, one section at a time.
Make sure you eliminate any drips the first time they appear. When you have covered the complete surface, leave the primer to dry. The recommended drying time depends partly of the product used. Refer to the packaging for further details.
Step 4 – Apply the Metal Paint
Provided that you are satisfied with the completion of the previous step having thoroughly inspected the surface, you can then apply the final coat. Ideally, you should use the same brand of metal paint as the primer as this will ensure compatibility. Apply it in the same manner as you did the primer, referring to the packaging for any additional instructions. When finished, leave it to dry for the length of time as directed and then inspect the surface to see that there are no imperfections.