DRYLOK Etch Concrete and Masonry Etch and Cleaner, 12 oz Powder
Two Jobs, Two Different Mixes
Getting the ratio right matters, because the same bottle does two different things at two different strengths.
| Cleaning and removing efflorescence | Full 12 oz bottle in 1 gallon of warm water. Covers about 300 sq ft. |
| Etching before paint or epoxy | Full 12 oz bottle in half a gallon of warm water, so double strength. Covers about 150 sq ft. |
How to Use It
- Clean off dirt, dust, grease and oil with a detergent solution first and let it dry.
- Mix the powder into warm water in a plastic container.
- Apply and leave it at least 20 minutes. The concrete should visibly bubble.
- Flush thoroughly with clean water. More than one rinse is usually needed.
- Let the surface dry at least 24 hours before staining or painting.
A Correctly Etched Surface
You are aiming for a texture like fine to medium grit sandpaper. If it still feels smooth, the etch has not worked and paint will peel off it later. If some areas refuse to bubble, that is a sign of deep oil or grease contamination in those spots. Scrub them again with a heavy duty detergent and re-etch, rather than painting over them and hoping.
The Mistake That Causes Callbacks
Under rinsing. If the solution is not flushed off thoroughly, the product recrystallises on the surface and looks exactly like the efflorescence you were trying to remove. People then repeat the treatment and get the same result. Rinse more than you think you need to, and if a scrapeable powder is left behind, repeat the etch and rinse properly.
Specifications and Cautions
| Product | DRYLOK Etch, order number 773390, formerly 01908 |
| Chemistry | Sulfamic acid, 100 percent solids powder |
| pH | 1.18 in a 1 percent solution |
| Dwell time | 20 to 30 minutes |
| Before painting or staining | Allow 24 hours drying |
| New concrete | Must cure at least 28 days before etching |
| Do not mix in | A galvanized container. Use plastic. |
| Protective equipment | Eye protection with side shields, chemical resistant gloves, protective footwear |
On Efflorescence Coming Back
Efflorescence comes from salts inside the block or concrete migrating out with moisture. Removing it does not remove the salts, and the manufacturer does not claim it prevents recurrence. If it keeps returning, the real problem is water moving through the masonry, and that has to be fixed at the source.
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