Prepare to strip the graffiti off the aluminum siding. Begin by covering vegetation surrounding the graffiti-stained aluminum siding with plastic drop cloths. Put on goggles and work gloves.
Dab soy-based paint stripper evenly over the graffiti, using a disposable paintbrush. Apply the paint stripper sparingly to avoid damaging the aluminum.
Cover the graffiti with another plastic drop cloth to keep the soy-based product from drying too rapidly. Seal the plastic to the siding with masking tape.
Wait for the graffiti to soften, which may take several hours. Abide by the specific soy-based paint stripper’s approximate dwell time recommendations.
Remove the plastic from the graffiti. Gently scrape the softened graffiti off the siding, using a scraper.
Rinse the siding thoroughly with water. Scrub remaining paint stripper and graffiti residue off the aluminum using a plastic scrub pad.