Acid Wash Formula for Etching Floors Before Painting

Use a scraper to remove any old paint or gunk on the surface of the floor.

Blow the area well with a gas or electric powered blower. Also use a shop vac to vacuum thoroughly against walls and in corners, to remove dirt and cobwebs.

Read the instructions carefully on the container of hydrochloric or phosphoric acid. These acids may be packaged in different strengths and purity levels.

Put on protective hand gear and eye goggles before opening acid containers, then pouring and mixing the acids.

Add 3/4 gallon of water to a bucket made of acid resistant material. Hydrochloric acid is commonly sold as a 30 percent solution mix, so mix approximately 15 to 20 ounces of hydrochloric acid into the water. Phosphoric acid mixes usually range from 20 to 40 percent strength. For a phosphoric mix add approximately 60 ounces of water to the bucket, then approximately 32 to 40 ounces of phosphoric acid.

Add the proper amount of acid to the water. Never add water to the acid. Always make sure the water is poured first and the acid is poured and mixed in after.

Apply the acid wash mix with a watering can in even rows. Never pour the acid wash solution out of the bucket onto the floor, as the acid will neutralize and cause uneven etching.

Work the acid wash mix in with a scrubbing broom. Allow the acid wash to sit for five to 10 minutes, then remove it with a shop vac or by hosing, if there is no grass nearby that can be destroyed.