Make sure to use the power washer on the lowest setting it has.
How to get paint off steel siding.
Use rubbing alcohol and a cloth to wipe the paint as much as you can.
But i would use the oil based rust oleum primer which by the way takes forever to dry.
For old dried up paint.
Depends on the weather but three or four or five hours is not unusual.
Apply liquid wax on a ball of steel wool and scrub the remaining paint.
It will definitely remove the dirt but the paint as well.
To use it add a few drops liquid dish soap to water and mix until it s sudsy.
This will help clean away all the dirt that accumulates on the steel siding.
It also helps to peel away the previous paint on the steel siding leaving it neat and clean.
You may have accidentally splattered some you may wish to recoat it with a different color or you may want to get rid of the paint altogether.
Then scrub the solution into the aluminum siding until the stain is gone.
Using too much pressure can dent your steel siding or damage the paint.
I had to use significant elbow grease not to some mention finger nail scraping for some of the larger stains.
In a few simple steps you will learn how to.
I suggest thinning it with 1 part thinner to 10 parts water and scrubbing on the stain only after testing a small inconspicuous area.
Oxiclean spray makes both a great laundry pre treatment product and a general household cleaning spray.
Wash the steel siding with trisodium phosphate tsp and use a pressure washer to rinse thoroughly.
Step 1 clean the steel siding.
Use your pressure washer to get to all the cracks and crevices you could not reach with the brush.
Paint thinner or acetone is said to remove paint stains but may also dull dull the finish on your siding.
The first step includes cleaning.
Liquid dish soap will enhance water s ability to remove paint spots and is the next best option if water did not work to remove the stain.
Set power washer to the lowest setting available.
A solvent based primer that is specifically for metal and will help prevent rust is usually the best way to go for this especially in areas that come into contact with rain or other moisture.
If you did not do a good job of scraping off the old paint or there is chalking that you can t get to come off then you should first paint with a primer.
And then i would use the rust oleum top coat.