Acid Staining Concrete / Cement Floors - Refinishing Old or Damaged Acid Stained Floors.
After a few years of wear, most acid stained floors will need to be refinished. This job is not difficult and just involves a few basic steps. The first step is to strip the floors. The second step is to add color back into the worn areas. The third step is to apply a glossy floor finish to the floor.
Step One - Stripping the Floor
You will need to purchase a gallon or so of floor stripper from Lowes or Home Depot. Make sure to get a stripper and not just a cleaner. Strippers remove the actual finish off of the floors. They generally work on both wax and acrylic gloss floors. This article will focus on the acrylic and polyurethane finishes. Wax floors will be similar.
Rent a floor buffer and get a scrub pad with it. Follow the instructions on the stripper. Apply the stripping solution to the floor and begin agitating the stripper into the floor with the buffer. You should begin to see finish come off and also some color. Do an area, mop off the excess and then do it again if necessary.
Here is the key. You are trying to strip the floors to the point that scratches begin to disappear and begin to look more like mottling than scratches. If you really want to make the floor look like it originally did then you would continue until all the finish is off the floor. We chose to strip down to a point where damaged areas no longer looked like scratches but instead began to look like what natural stone would look like. For example, if you scratched your car you could strip the entire car and repaint or you could sand the scratch down until it is smooth and then recoat. The idea is to
fool the viewer into believing that the scratches and worn areas are just part of the overall mottled look of the floor. In areas that are badly scratched spend more time with the stripper and buffer. In undamaged areas just make one run over it with a mild solution of stripper to prepare it for recoating. There is no need to damage undamaged floor areas by over stripping.
Step Two - Adding Color
Once you have stripped the damaged areas down and tapered out the scratches, worn areas, etc.. you will most likely need to add some color to the floors in the areas that were most damaged. This can be done in two ways.
The first way is to use the same acid stain that you used when the floors were originally done. Floors that have been acid stained tend to not respond as well to additional acid staining but they will take color. For our floors we used the acid full strength. Two coats gave us the results we were needing. Apply, let it sit for as long as you want and then mop off and apply again if needed. When you are done just mop if off one last time.
Now you have the option of adding additional color. I use waterbased wood stains or concrete stains from Lowes. You can either use the stain by itself or mixed with a little waterbased sealer and water. I use a little sealer and water with my stain. You can apply it any way you choose. Sponging it in works well. The idea is to blend the damaged areas back in with the undamaged areas. Choose your colors wisely and apply the color sparingly. Slowly build up areas instead of trying to cover all at one time. If you add too much it will look like you painted your floors.
Applying the Glossy Floor Finish
Once you are satisfied with the look of your floors you are ready to apply the finish. We use the Sunnyside finish from PR Supply. Before applying make sure the floors are free of hair, sand, lint, etc.. Also, check for these between coats. Apply a few coats of finish and you are done.
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