Painting aluminum follows a different approach so before moving forward, check what kind of color has already been used on the aluminum siding. For steel, latex paint is excellent. If you do not understand the material which has been used for the siding, ask some professional help. And to know the type of paint also, professional can guide you better. To check if the material is aluminum or steel, tap on it with a magnet, and if it doesn’t stick, it is aluminum. Plus, if bumps are there instead of breakage, then also it is aluminum.
Next, you need to clean the field with a washer. Angle the spray in the rain direction to get rid of the siding damage. Plus, don’t forget to rinse off the area if you use any chemicals for washing. Or else it can damage the final paint. After drying, if you see any powdery material coming out, don’t get panic. It is chalking which itself is a cleaner for aluminum. To remove it, use a detergent containing TSP.
Then, you need to sand the siding to remove any chipped paint or metal fillings. Don’t do it too hard as the molding can get damaged because aluminum is easily bendable. Always try not to go below 80 grit sandpaper as it can ruin the aluminum siding.
Choose a primer, specifically an oil-based primer. Such primer gives the extra layer of protection to the siding from outside elements. Or acrylic primer is also an option, but for that, you have to use acrylic paint only. So be cautious while choosing any primer or paint. Avoid latex primer as it forms gas bubbles with time thus leading to the removal of paint from the siding.
Choose the right type of paint. I would say to use acrylic exterior grade paint as it is mainly for aluminum metal. Choose satin finish paint than matte one.
Painting method is also important to consider. The best way to paint aluminum siding is using a paint sprayer, but it is the most expensive method over others, i.e., roller or brush. Go for airless sprayer having .017 gun tip as it gives smooth results. And if you use roller or brush, then try painting with lambswool roller or synthetic fiber brush.
Try painting the sliding using a ladder. Avoiding the ladder will leave the paint to spread in an uneven manner and splotchy way.
Next, start applying primer on the siding. Go for at least two coats to get proper coverage. If you see any metal or old paint on the primer coating, don’t worry. Just apply the thin layer of primer to let it dry fast. Always start priming from the sides and not in the middle. It will make the drying in an even fashion. Give the primer enough time to dry or else bubbles will form making the siding look ugly. 4 hours are enough for drying the primer.
Start painting the siding now. Do long strokes of paint but evenly. Don’t overdo the picture as it will give a un-uniform look and if the paint drips, then definitely you are using too much of the paint. Start from the top and radiate downwards. It is because if paint drips, it will not ruin the already done painting. If the siding is horizontal, move from left to right and if vertical, do it up to down. This way you will get even coats and cover spots if any.
Paint consumes 2 hours in total to get dried. What you can do is touch the siding gently from the area which is not noticeable. If you don’t feel any tackiness or stickiness, then the paint is dry. Now you can do the second coating of paint. Always finish the painting of siding in one go or else it will show visible lines if half part is dried and the remaining is still wet.
Before doing the second coat, check if any bubbles or bumps are there. If you find any, remove them using the sandpaper and then apply the second coat. Use the sandpaper gently on the first coat or else you will get the paint out from the siding. Don’t go too fast in this process and check that the first coat is completely dried.
The second coat is not essential, but it is the best suggestion to give a clean and professional look. Plus, the second coat removes the flaws in the first coat thus adding durability factor to the paint.
Lastly, if you see any lines in the coating, it shows that you paint so slowly. Increase your speed of painting to get smooth coats. Avoid stopping in between as it will give lines on the siding. Always paint in panels and finish the whole group in one go. Happy painting!!