If you have aluminum siding installed on the exterior of your home, you have selected a very rust-resistant material that should last you a very long time. However, aluminum siding is not immune to problems related to rust. Aluminum siding, like any material, can be stained by rust that comes from another metal object. Rust stains on aluminum siding can be a serious problem that can be very difficult to remove. However, if you have rust stains on your aluminum siding, all is not lost. It is possible to remove the rust stains on your aluminum siding. What follows should give you all the information you need to do it yourself.
Step 1 - Rinsing
Before you do anything complicated, get out your garden hose and go over the rust stains with water. If you use a decent amount of pressure, you may remove some of the rust stain—or even all of it, though this is unlikely—with this step. However, if this is not enough to remove even a little bit of the rust stain, it is still a helpful step as it prepares for the next thing that you must do.
Step 2 - Washing
You can do a great deal to remove rust stains from your aluminum siding with ordinary dish soap and water. Fill a bucket with water and squirt in a decent amount of dish soap. Stir it up until a lather will form, and then soak your brush in the mixture of soap and water until it fills up thoroughly.
Once your brush is nice and wet, use it to clean off the rust stains. Because aluminum siding is extremely durable and resilient, you can scrub it extremely hard with your brush. There is no reason to go easy on the rust stains on your aluminum siding, so scrub them as hard as you can. You should occasionally rinse off the area with your hose to see your progress and carry away and bits of the rust that you have dislodged from your aluminum siding.
It is possible that you will be able to remove all of the rust stains from your aluminum siding this way. Because of this, it is important to not be discouraged and move to the next step too quickly. Soap, water, and scrubbing can definitely be enough to remove a lot of rust stains, and are preferable to the alternative because they are mild and will not damage the paint.
Step 3 - CLR
If soap, water, and scrubbing are not enough to remove the rust stains from your aluminum siding, you still have one more option—CLR, or Calcium, Lime and Rust Remover. CLR can be purchased at your local hardware store.
First, put on rubber gloves to protect your hands. Even though you are working outside, take care to avoid breathing the fumes CLR produces. Apply CLR to your rag, and use the rag to cover your rust stain in CLR. Do not scrub, simply wait for 2 minutes and then rinse the area with your hose.
CLR may damage your home's paint, so avoid using it if possible.