On 10 Oct 2006 13:21:00 -0700, "SwordAngel"
wrote:

Hello,
My driveway is paved with red and gray bricks. Due to a porcelain tile
laying project on my front door stairs, some of the bricks got stained
with a diluted mixture of Keraply (R) (an acrylic latex dry-set mortar
additive) and porcelain powder (from tile cutting). How do I clean up
the stains? I called Mapei, the manufacturer of Keraply, and the
technician who answered doesn't have a sure solution. He suggests,
however, that hydrochloric acid (a.k.a. muriatic acid) may do the job
but that I should check with a masonry/brick laying expert.

Would somebody know the answer? Would vinegar also work? (I know that
vinegar is a much less potent acidic solution than hydrochloric acid,
but I simply have way too much white vinegar at home.)

Whatever condenses out of oil-furnace exhaust is an
EXCELLENT mortar solvent, and doesn't seem to degrade
actual bricks much. That's what, sulferic acid?