Use muriatic acid or another acid etching material such as Klean Strip Green Muriatic Acid, a safer muriatic acid or Hydro-Etch 1000 which is a modified phosphoric acid which is not as harmful as traditional muriatic acids. Muriactic acid is one of the most dangerous chemicals you can buy for home use and it can damage nearly everything it touches. We really like the Hydro-Etch 1000 product since in most cases it does just as good of a job as muriatic acid but with less danger. It is also an excellent choice when you are looking to remove efflorescence from concrete and masonry substrates.
Acid Etching Process:
Remove all furniture, equipment and objects from the concrete floor you are going to be etching, sweep up or shop vacuum any dust and dirt.
Remove all oils and greases prior to etching, this can be done by using a degreaser, laundry detergent or Dawn concentrated dish soap.
Hose down the entire area you are going to be etching. Spread the water and make sure it is not pooling or puddling, the concrete should remain this wet throughout the acid etching process.
The usual dilution ratio is 3 to 4 parts water to 1 part acid. Do not use a metal container to mix the acid and water. Important: Always pour acid into water, never pour water into acid since the acid can splash back into your face and lead to injury. During the mixing stage wear long sleeves, gloves, eye protection and a face mask to protect against fumes.
After the acid is mixed with water test in a small area to make sure the ratio is accurate, you will be able to tell since the concrete will begin to bubble and react. If you dont see bubbles when the acid first comes into contact with the concrete the mixture is not strong enough.
It is easiest to use a sprayer or watering can to apply the mixed acid to the floor. After spraying acid on the floor you can use a squeegee or floor machine to spread the acid mixture. Remember that the floor needs to stay wet throughout the entire acid etching process. Do not let the acid dry on the floor, if you notice that it is starting to dry you will need to hose down the areas.
After the acid has been applied wait about 2-15 minutes for the floor to stop bubbling. Throughout this process the acid is reacting with the floor, opening up the pores of the concrete preparing it to accept a sealer. If there are spots where the acid is not reacting with the concrete there could be residual oil or grease left on the floor and you may need to use a floor grinder to prepare the floor in these areas.
After the 2-15 minutes rinse off the acid from the floor. The next step is to neutralize the surface and reduce the pH of the concrete. You can neutralize the concrete using 1 cup baking soda dissolved in 1 cup water or 4 ounces of household ammonia mixed into 1 gallon of water. Let the neutralizing solution sit for a minimum of 10 minutes. You can then rinse off the neutralizing solution and drain it or shop vacuum it up.
The concrete should now have a cleaner, brighter appearance and it should have the texture of medium grit sandpaper. Rinse the concrete twice and suck up the excess with a shop vacuum. If the concrete is not rinsed enough a white powdery residue will be left on the floor when it dries. This can be removed by rinsing the concrete again.
- Wear protective clothing such as safety googles, gloves, long sleeves and close toe shoes.
- Do not breathe fumes, and use a face mask respirator
- ALWAYS POUR ACID INTO WATER, NOT water into acid.
- Effective pH levels prior to applying a sealer or coating are 6.0-9.0. If the range is below 6.0 there may still be acid residue in the pores of the concrete.
- Use a plastic drop cloth to protect anything you don’t want to get splashed.
- Don’t acid etch in weather below 50 degrees F.
- After etching make sure the floor has dried out before applying a concrete sealer or coating.
The post is based on a very informative article on wikiHow.com titled, How to Acid Etch Concrete.
One of the most frustrating scenes to walk into is a leaking chimney. It is one of the applications that you don’t give much thought to until it is too late. Because bricks, stone, masonry are extremely porous they are at high risk of leakage if left unsealed. In order to prevent water leakage, mold, mildew and efflorescence from occurring to your chimney these are the steps to take:
- Clean the chimney, make sure all mold, mildew and efflorescence are completely removed.
- Fix any cracks in the mortar, or if the chimney is severely damaged re-point the chimney.
- Use a waterproofing sealer, like this one found at homedepot.com which is a silane/siloxane blend that will waterproof and protect your chimney from future leaks and water damage for over 10 years.
There are a few different options when it comes to coloring concrete:
1. Integral coloring
Integral color is used when new concrete is being poured to add color to the concrete during the mixing process. The color is either in liquid or powder form and allows color to be added to the entire depth of the slab. This allows for a uniform color for a large amount of square footage.
2. Shake on color
Shake on color is used on new concrete by broadcasting small pigments of powder that work their way into the concrete. Water from the newly poured concrete wets the powder and causes the the color to bond with the top layer of concrete.
3. Acid Stains
Acid stains are chemically reactive and react with minerals in the concrete to create a unique, durable color effect. Acid stains are hazardous and must be neutralized after application. Acid stains can be used on new or old concrete slabs.
4. Acetone dyes
Acetone stains and dyes are solvent based and hazardous but can create vivid beautiful colors. They are not UV stable so a protective sealer should be used on top of an acetone dye to lock in the color.
5. Water-based dyes
Water based dyes are safe and easy to apply with all of the colors able to be mixed together to create patterns and effects. Since they are not UV stable a protective sealer should be used on top of water based dyes to lock in the color.
6. Color densifiers
Color densifiers are a new technology in which a colored, water based, lithium silicate solution is used. They allow you to densify the concrete while coloring it in the same step. The color densifiers are UV stable but a protective sealer can be used on top of a color densifier to lock in the color and add an additional sheen.
While concrete is exceptionally strong, one of the biggest potential threats to undermining that threat can be found in the form of moisture. Somewhat paradoxically, moisture is actually an integral part of concrete from its very beginnings. Concrete is created by mixing together Portland cement, some sort of aggregate, and water. Without water, the concrete would not adhere and bond together so strongly. Furthermore, during the curing process after the concrete is poured, the moisture levels of the concrete have to be kept stable, which often requires a sprinkler to douse the concrete with water constantly.
If concrete requires a certain amount of moisture, why do all of these concrete sealing products claim to prevent the passage of moisture through your concrete? Well, what these products really mean is that they will prevent the passage and entrance of excess moisture through and into your concrete. A certain level of moisture and moisture passage is healthy for a concrete slab – without it, the concrete will likely crack and crumble from excessive dryness. Therefore, a certain level of moisture needs to be in the concrete for it to reach its maximum potential.
This is where the concept of relative humidity comes in. All concrete needs to be kept at a certain stable reading of relative humidity for its strength to be achieved. Relative humidity is simply a measure of the amount of moisture in the slab. Testing for relative humidity is an easy process that involves using special relative humidity probes that you can insert into the concrete. Once within the concrete via a small hole, the probe will measure and record the percentage of moisture (the relative humidity) in your concrete. If the moisture is acceptable, then there are no problems. However, if the level of moisture is too high, you’ll need to take the appropriate steps to lock out that moisture in the future.
Polyaspartics are fast becoming a veritable wonder product on the concrete sealer market today. These products are relatively new derivatives of the traditional aliphatic urethanes that have been around for a lot longer. Aliphatic urethanes are typically used as topcoats that feature incredibly strong levels of resistance to the most extreme weather conditions, water exposure, heat, abrasions, and other such threats to concrete. While urethanes are typically used as the topcoats in concert with epoxy base layers, they can also stand on their own.
Polyaspartics are newer product that are similar to urethanes. The biggest difference between a polyaspartic concrete sealer and a traditional urethane is that the polyaspartics feature incredibly short dry times. They can be applied to the large floor of a retail store, for instance, only to dry completely overnight and be ready for the store to open for full service the next day.
However, the biggest drawback to polyaspartics is their short pot-life. The pot-life is the technical jargon term for the amount of time before being applied that a solution can last without being ruined. That is to say, once you mix a polyaspartic, it all has to be applied within a certain (short) period of time before it becomes unusable. A short pot-life is typical for a product that cures rapidly, as do polyaspartics. And, while this can be an inconvenience, it is not the end of the world, as there are proven ways to work around the limitation.
A general rule of thumb is that polyaspartics with a lower solids content will have a longer pot-life. Polyaspartics typically have a solids content between 70% to 100%; therefore, a product with a solids content of 70% will have a longer pot-life than a product with a 100% solids content. Another factor that makes the pot-life shorter is the amount of moisture, typically in the form of humidity, that the mixed polyaspartic is exposed to – the more moisture/humidity, the shorter the pot-life.
In order to extend the effectiveness of the polyaspartic, it is best to mix small amounts of the product more often in order to work around the short pot-life. As polyaspartics need to be mixed together before use, it is best to mix as you go, applying the polyaspartic between mixing breaks (even if this means mixing more often), in order to maximize the potential.