Painting different surfaces requires different surface preparation procedures. For painting new concrete, the steps include neutralizing the surface. And, there are important things to remember when you plan to do so. Keep these tips in mind.
Cure First, Then Neutralize
Working on new concrete will require surface preparation. This includes curing it for 14 to 28 days under normal weather conditions first. After curing, the concrete will then need to be neutralized—that’s paglalason in Filipino painting terminology. Note, however, that if the new concrete has been cured for more than 28 days, it will no longer need to be neutralized.
But why neutralize anyway? Concrete is made up of different components including cement, aggregates like sand and coarse gravel, and water. The sand in the concrete will have salt in it.
When a concrete surface is painted without being neutralized, the water in the concrete will evaporate and leave behind salt on the surface. The salt will look like crusty, white patches on the paint—this is a painting problem called efflorescence. To avoid efflorescence, we neutralize a concrete surface before painting.
Use the Right Product
Boysen Masonry Neutralizer is specifically formulated to neutralize a concrete surface. For those interested in the technical details, this product is a diluted phosphoric acid solution.
To use it to neutralize a concrete surface, dilute 1 part of Masonry Neutralizer with 16 parts of clean water. Apply the resulting mixture to the surface with a paintbrush or roller. Leave this overnight.
The next day, you’ll notice white crystals have formed on your new concrete. Rinse the surface with water and let it dry completely before you begin painting.
Skip the Neutralizer If You’re Applying Skimcoat
Typically, there is no need to neutralize a concrete wall prior to painting if you’re planning to apply skimcoat. The concrete will only need to be cured for the allotted 14 to 28 days and then you can proceed to applying skimcoat. The neutralizing step can be skipped.
Skimcoat is a surface preparation product and an alternative plastering material that corrects surface imperfections, giving concrete walls a smooth appearance. It repairs bubbles, honeycombs, and other concrete defects like waviness and plumbness.
If you need a product recommendation, check out the Konstrukt line skimcoat products. For example, there’s Konstrukt Permaplast K-201 High Performance Acrylic Skimcoat. Use it with different concrete paint types like water-based, solvent-based, or elastomeric. It can also be used on both interior and exterior applications. Learn more about it here.
If you have any questions or inquiries about Boysen products, our technical team will be happy to assist you. Send an email to ask@myboysen.com or call (02) 8363-9738 local 413 to 418 during office hours for a one-on-one consultation.
