Exam 31: Removing Various Stains From Masonry Walls

The proprietary cleaner, SURE KLEAN 600 should be mixed _____ water (by volume).

Silicic acid scum creates a grayish-white haze on the face of brick, which is referred to as _____ .

_____ stains are usually difficult to remove and should be scrubbed with a scouring powder, preferably one containing bleach.

Masonry cleaning products can be corrosive and toxic in nature.

Manganese stains occur on mortar joints and are typically _____ .

Green-stained brick often show no sign of a stain until they are _____ .

To remove green stains from a wall, spray the wall with _____ .

Use a cloth saturated with gasoline to remove an asphalt or tar stain that has not completely dried.

For particularly difficult stains, spike the cleaning solution with larger doses of the cleaning solution than the directions recommend.

To remove _____ stains, mix together 1 part ammonium chloride or sal ammoniac and 4 parts powdered talc.

Generally, _____ refers to a white, powdery substance on masonry walls.

A masking solution of _____ can be used to darken lighter color brick.

Permanent removal of manganese stains is simple.

Most of the time, efflorescence cannot be removed with only water and a scrub brush.

Fresh paint can be removed using a solution of _____ .