You don't want all your hard work to go to waste by not neutralizing the acid stain properly. Ensuring proper neutralization is crucial for sealer bonding and a durable, aesthetically pleasing finish. Without it, you might end up with a peeling, blotchy surface that just won't do justice to your efforts.
If you're planning on sealing your concrete, this is the most important step. If you do not neutralize and clean the floor with Neutra Clean™, your Kemiko sealer cannot bond correctly. More about Kemiko Neutra Clean™ Neutralizer and Degreaser. More about Kemiko Stone Tone™ Concrete Acid Stain.
Allow the stain to dry for a full 8 hours or overnight before neutralizing the stain. This will ensure the stain penetrates into the surface completely.
Allow the acid stain to penetrate the entire concrete surface and fully develop its color for from 5 to 24 hours (check manufacturer's instructions for exact timing). The longer you leave the acid stain on, the deeper the final hue will be.
Once that stain chemically reacts for a minimum of four to six hours—typically, you'll leave an acid stain overnight—it brings salts to the surface. All of these salts are like a powdery residue.
If you leave it on for too long, the chemicals in the stain can start to break down the surface of the wood, causing it to flake off or peel. Sometimes, the excess stain may redissolve, giving you undesirable results.
Acid staining is a chemical reaction that permanently changes the color of the concrete surface. If you want to stain old concrete, using a true acid stain is always the best option.
Over time, it can destroy concrete as the acid weakens its structure. This will cause scaling, pitting, peeling, and cracking. If the acid wash gets into the soil, it will evaporate on the surface but remain beneath the surface (just like it does with concrete).
You can use mops, water hoses, wet/dry vacs, and/or extremely soft bristle brooms to neutralize the stain and remove the residue. Neutralize with water and either baking soda, t.s.p., or ammonia and then final rinse twice with clean water only. We recommend using 12 to 16 ounces of ammonia per mop bucket.
Allow acid stain to react with the concrete floor for at least 6 hours. Clean residue and pour water on the floor to approximate the final color. If darker color is desired, apply a second coat. Clean residue from floor with degreaser and neutralizer solution using an acid brush.
A ½ teaspoon of baking soda will neutralize 1 cup of an acidic ingredient. Just a little baking math – Recipes often employ a combination of baking powder and baking soda, using just enough baking soda to neutralize the acid in the recipe, but also enough total leavener to lift the flour in the recipe.
Sealing your concrete isn't really a labor-intensive, nor costly, job. By sealing your concrete every 2-5 years, as recommended by experts, you should keep your floor in good shape, preventing cracks, pitting, and additional damage.
There are many ways to go about layering acid stains, but a common approach is to cover the entire floor with a diluted color, then spot-stain sections with less diluted or undiluted colors, often using faux techniques such as ragging or sponging.
Acid stains are a reactive coloring process that penetrates into the porous concrete surface. This is probably the most permanent of all coloring options but is usually limited to eight colors.
Acid staining damages the concrete to some extent and will need to receive some form of a resinous coating on top to be usable in most business settings. While it does give it a flashier look than polishing, acid stained concrete will always be subject to damaging easier than polished concrete.
Though new concrete may not always require a second coat of acid stain, older concrete does require two coats of stain for complete coverage. For a more diffuse look, spray the stain onto the surface without brushing.
No, the vibrancy and color tone in acid stains do not fade. However, the physical top layer of concrete which contains the stain can be worn away through use, which can give the appearance of fading. Stone Surface Specialists can apply a special sealer on your newly-stained concrete to prevent this.
Brushing acid stain is different for all concrete surfaces. It's easier to hand brush a smooth hard-troweled floor than it is to brush a heavily broomed floor. Be aware and prepared for this ahead of time. It's also easier to see brush marks on smooth surfaces than it is to see them on rougher textures.
A white haze, white streaks or white, powdery dust on the surface after drying is caused by waiting too long before rinsing or by inadequate rinsing. The white powder is a combination of cement particles released from the surface and a precipitate byproduct of the etching reaction, insoluble calcium phosphate.
High concentrations of muriatic acid can etch concrete, glass, remove paint, dull chrome, and cause other issues.
Keep a supply of baking soda or garden lime nearby in case you need to quickly neutralize muriatic acid. While sprinkling these substances full-strength will work, the best plan is to mix ½ cup of baking soda and a quart of water in a sealed spray bottle and keep it nearby.
Scrub the acid solution: Once the solution is applied, lightly scrub it into the concrete with a push broom or long handled scrub brush. This helps to create a uniform etch of the concrete. Let the solution sit from 2 – 15 minutes while it continues to fizz and bubble.
How deep does the acid stain react through the concrete surface? Concrete thickness can vary from ¼” to over 3′. However, depending on the finish (how it was troweled) and porosity of the concrete surface, the penetration of the acid reaction may be only 1/16″ – 3/16″.
Protecting the Acid Stained Finish
It would crumble under foot traffic and quickly turn dull. The surface must be protected with a clear coating which will also provide gloss and enhance the hues. The choice of topical sealers is very wide and includes water- or solvent-based acrylics, urethanes, and epoxies.
Stains are effective in restoring glaze to dull, shabby concrete surfaces. Slabs with none to minimal cracks, blemishes, and other flaws are ideal for staining. Stains enhance the appearance of the surface; they don't conceal defects.