Project Garage, Part 3: New Flooring


Prepping the garage floors
The list of supplies used for prepping the garage floors for floor paint are easy to find.  But you might want to save any fertilizer purchases for another day and store unless you want to appear on the Homeland Security terrorist suspect list!

Start prepping the floors by using a putty knife to remove loose paint or spackle, and lacquer thinner and TSP cleaner to get the concrete clean. To detect sealants and to acid etch the concrete, you’ll need muriatic (hydrochloric) acid, ammonia, an acid brush (stiff bristle broom), a 5 gallon container, and a sprinkling can. Rubber boots, neoprene gloves, facemasks, and goggles are highly recommended while using the acid and ammonia. All of these can be found at a home supply store and will cost about $50-100 depending on how large your garage is.

To check the concrete for sealants, pour a small amount of 50% diluted muriatic acid onto the concrete. If it does not bubble or hiss, a sealant is present and must be removed with a floor sander before proceeding. Rinse the acid away. Use the putty knife to scrape off all paint splatters, caked drywall, mud, or anything on the surface of the concrete. Remove excess oil on the concrete with lacquer thinner and rags. Apply TSP cleaner with a stiff bristle broom to the entire floor to clean it. Scrub well and rinse off the entire area. The acid etching is potentially hazardous and should be done carefully. It will permanently damage aluminum doors and painted metal surfaces. If your entire garage is not empty, tape off the area you will be working in. Rinse down the space to be acid etched and keep it wet at all times. Don’t let the acid dry on the concrete. It will weaken the adhesion of the paint.

Floor prepFloor prep
Prepping the garage floor for paint is quite the workout but is the only way to get the floor in perfect condition for the paint to last a long time.  Lure some friends to help out with pizza and beer…

Mix 1 gallon of muriatic acid to 2 gallons of water in a 5 gallon container. Always mix the acid into the water, not the water into the acid, and watch for splashes! The easiest way to acid etch is to rent a floor buffer with a plastic bristle scrubber pad that is suitable for doing an acid wash. The cheaper way (and my choice) is to use a stiff bristle brush to work the acid in. Pour the acid solution into a garden sprinkling can and apply over a portion of the concrete. Scrub the acid in aggressively and rinse away. Although you want to keep the floor wet, use a floor squeegee to sop up any puddles so they don’t dilute the mixture. This is better as a two person job, one to scrub the acid in while the other rinses. Scrub the acid in both directions, up and down and left to right. If the acid etching is done by hand, two acid applications are necessary. The concrete should resemble 80-100 grit sandpaper once completed. As this garage is the size of a studio apartment, the space was split in half to clean and paint. There was a noticeably rougher feel on the etched side versus the smooth side after the first day of prepping.

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