Black stuff on aluminum. Impossible to remove with pressure washer – even bleach doesn’t cut it. Figured out what does today: ammonia, dishsoap and a pine-oil type cleaner. Spray it on, you can let it dry – longer it sits, the better. Wipe off with microfiber cloth. A miracle.
When my mother came out, looked at a section I cleaned completely and asked, “Did you PAINT it? Why is it so white?” – it feels good to FINALLY figure out the right chemical that removes a stain. I remembered that ammonia removes tough carbon stains and I figured, well, never tried ammonia on it before, i can add dishsoap to loosen up the dirt, and oil-type soap always seems to get some things other cleaners don’t… i just never thought to do it like that before. Yes, the little things DO make me happy.