Glycolic acid for concrete and masonry cleaners
What is Glycolic acid?
Glycolic acid (hydroxyacetic acid) is the first member of the series of alpha-hydroxy carboxylic acids, which means it is one of the smallest organic molecules with both acid and alcohol functionality. The product is manufactured by Chemours in the United States (Belle, WV) with excellent supply stability and outstanding quality.
Glycolic acid is preferred in concrete cleaners and removers as it combines the essential cleaning attributes, required acidity, and necessary metal complexing capability for concrete cleaners and cement dissolving formulations.
Glycolic acid is an excellent alternative to corrosive acids, such as HCl, and more efficient than organic acids, such as citric and acetic acids, in concrete and grout removers.
Why Glycolic acid for concrete cleaners and dissolvers?
Glycolic acid is featured with a small molecular size and excellent water solubility that enables deep penetration in concrete residues and adequately reacts with particles from within. Due to its low corrosivity, it can be safely used on metal and equipment surfaces without causing etching or damage. It is also easier to dispose of than many other acids, such as phosphoric and HCl, as it is readily biodegradable.
Glycolic acid attributes in concrete cleaners and dissolvers
- Superior cleaning agent for penetrating and loosening concrete
- Excellent complexing agent for calcium and metals
- Chloride-free for low to no corrosion on most metal and coatings
- Improved cleaning efficacy for minerals and metal deposits
- Broad metal sequestering properties
- Excellent solubility of hard water salts (calcium, magnesium, and metasilicates)
- Excellent rinsability with minimal residue on cleaned substrates
- Outstanding formulation compatibility and can be blended with other acids for improved performance
- Easy to handle and readily dilutable to any desired concentration
- Low toxicity, biodegradable, negligible odor, and non-flammable
Glycolic acid corrosion study vs. other acids
The following table shows the corrosion rate of glycolic, phosphoric, and hydrochloric acids tested on 1018 carbon steel, 1100 aluminum, 304, and 316 stainless steel. The results are showing the % weight loss at 23°C (73°F) for 48 hours with no agitation.
Metal Type/ Acid | Glycolic acid (HO-CH2CO2H) | Phosphoric acid (H3PO4) | Hydrochloric acid (HCl) |
|---|---|---|---|
| 1018 Carbon Steel | 0.17 | 0.64 | 2.03 |
| 1100 Aluminum | 0.009 | 1.39 | -- |
304 Stainless Steel | 0.008 | 0.011 | 0.53 |
| 316 Stainless | 0.002 | 0.002 | 0.94 |
Concrete cleaners and removers starting formulation
| Standard Concentrate | Standard Ready-To-Use (Diluted) | Ingredient Examples | ||
|
Glycolic Acid, |
80.0% | Glycolic Acid, 70% Tech Grade |
20.0% | Chemours Glycolic Acid, 70% Tech Grade |
|
Nonionic alcohol |
4.0% | Nonionic alcohol ethoxylate surfactant |
1.0% | Tergitol 15-S-9 (Dow) |
| DPM Glycol Ether | 16.0% | DPM Glycol Ether | 4.0% | Dowanol DPM (Dow) |
| Water | 0.0% | Water | 75.0 | Water |
| Low/ No Corrosion Concentrate | Low/ No Corrosion Ready-To-Use (Diluted) | Ingredient Examples | ||
|
Glycolic Acid, 70% Tech Grade |
76.0% | Glycolic Acid, 70% Tech Grade | 20.0% | Chemours Glycolic Acid, 70% Tech Grade |
|
Nonionic alcohol |
4.0% | Nonionic alcohol ethoxylate surfactant |
1.0% | Tergitol 15-S-9 (Dow) |
| DPM Glycol Ether | 12.0% | DPM Glycol Ether | 4.0% | Dowanol DPM (Dow) |
| Corrosion Inhibitor | 8.0% | Corrosion Inhibitor | 2.0% | Rodine 103 |
| Water | 0.0% | Water | 73.0% | Water |
Use instructions for Glycolic acid formulations:
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Dilute with tap water before use 1:4 (For ready-to-use formulations only)
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Spray on the substrate or the surface to remove or clean the concrete
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Wait at least 30 minutes (allowing to react overnight or between shifts is acceptable).
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Power-wash equipment and parts to remove residual concrete
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Extremely heavy residuals may require two treatments.
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Wear appropriate personal protection equipment.
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As with all acids, they should not be sprayed on hot surfaces.
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