Things You'll Need
Stiff scrub brush
Masking tape and/or plastic sheets
2 large buckets
Coffee grounds (optional)
Iron sulfate is commonly used in medicine and as a fertilizer for plants. Most people would probably never think of staining concrete with iron sulfate. In fact, it offers one way to change the color of concrete floors without painting them. Iron sulfate staining produces a reddish-brown color on the concrete, which can be lightened or darkened, depending on the amount of the product that is used. You can easily transform your concrete surface by staining it with iron sulfate.
Clean the concrete thoroughly prior to applying the stain. Sweep the floor with a broom to remove loose dust and dirt. Scrub the floor with a stiff scrub brush and soapy water to remove stains. Rinse the concrete with plain water and allow it to dry completely. Scrape off any imperfections in the concrete, using a putty knife. Tape off and/or hand plastic sheets to cover any areas you wish to avoid getting the stain on.
Mix the iron sulfate with water to create the stain. The ratio of iron sulfate to water will vary depending on the look you wish to achieve. Mix 16 oz. of iron sulfate with one gallon of water to create an orange-colored stain. Combine two pounds of iron sulfate, one gallon of water, and two cups of coffee grounds to create a darker stain. Mix the solution into a large bucket and thoroughly combine it, using a long-stemmed paint stirrer. Mix the stain in small batches, only about enough to cover approximately ten square feet at one time. Mixing too much in advance will cause the iron sulfate to settle at the bottom.
Strain the iron sulfate mixture. Have a helper hold a large piece of cheesecloth over another large bucket. Pour the iron sulfate mixture through the cheesecloth to remove any large chunks.
Dip a large rag into the bucket of the iron sulfate mixture. Generously apply the stain to the floor using the rag. Bunch up the rag and spread the stain evenly across the floor, working in sections of about 10 square feet. There is no "right" way to spread the stain onto the floor. Be creative. Staining concrete is as much an art as it is a remodeling project.
Apply at least two more coats of stain to the floor. Allow the floor to dry in between coats and sweep the floor with a dust mop prior to applying the new coat of stain.
Apply a sealant to the floor once the final coat of stain has dried completely. Sweep and mop the floor thoroughly prior to applying the sealant and allow it to dry. Apply between three and five coats of sealant to protect the floor properly.
Wear socks, rather than shoes, while applying the stain to the floor. This will reduce footprints on the floor.
Wear protective eye and face gear, as well as old clothing that covers your arms and legs, to protect your skin and body from the iron sulfate.