How to Keep an Acid Stain From Bleeding

Scoring Concrete

• 1

  Mark the borders between each of the colors of your pattern, using the chalk line. Hold your saw so the blade just touches the surface of the concrete before turning it on.

• 2

  Score the concrete by carefully moving the exposed blade against the chalk line to create a groove about an eighth-inch deep between each color section.

• 3

  Even the groove, if necessary, with the abrasive wheel of an angle grinder. You can also use a Dremel tool to even it.

• 4

  Apply acid stain to each section, using a brush or other applicator according to directions on the container. Apply the stain as close as you can to the scored line before applying the next color to the next section. Stain will spread up to the scored line, and the small amounts that sink into scored areas won't be noticeable except to add to the appearance of your patterns.

• 5

  Allow the stain sufficient reaction time as recommended by the manufacture before applying sealant to the stained surface. You can apply sealant as you normally would. Any excess sealant that runs into the grooves will be absorbed by the concrete.

Using a Thickening Agent

• 6

  Lay out your stencil over the surface to be stained or use acid-resistant tape to mark off the borders of an area you want to stain with a particular color.

• 7

  Pour a small amount of thickening agent into an acid-resistant mixing vessel. Add about half that amount of acid stain to the thickening agent and mix with a plastic or other acid-resistant mixing stick until the consistency is even.

• 8

  Brush a small amount of the mixture onto an inconspicuous spot on your concrete surface or onto a corner of a concrete surface such as a basement or garage floor that no one will see. As the thickening agent dilutes the color, check that it remains dark enough. Add more stain if the color is too weak and remix.

• 9

  Apply the final mixture with a hard brush inside the outlines of your stencil or taped area. Allow the stain to penetrate the concrete until the color appears as you desire. Remove excess stain from the stained area as well as from the template or tape, using a slightly moist sponge or rag.

• 10

  Mark off the area for your next color or lay the template for that section. Repeat steps 1 to 6 for each section. Seal as desired once all stain has dried.