Apr 2018 HOW TO REMOVE CONCRETE SEALERS
While a tall order and not something most contractors seek to do for business (or for pleasure), removing concrete sealers can be a challenging and messy task. Sephaku Cement discusses the intricacies and what you need to know about removing concrete sealers with as little fuss, mess and mishap as possible.
Before proceeding with removing a concrete sealer your contractor will want to establish what type of sealer was originally applied to the concrete surface, in doing so this will determine the best suited approach to tackle this undesirable task. Determining if the concrete was sealed with water based or solvent based product is key to successfully removing the coating by applying the most relevant and appropriate methods.
- How to tell if the concrete sealant is water or solvent based
To understand what type of concrete sealant was initially applied to the cement surface, test this by pouring a small amount of Xylene to the area. After allowing the product to sit on the concrete surface for about 30 seconds, remove the excess Xylene and with clean hands, touch the area to feel if the surface is tacky to the touch. If the surface is sticky it’s likely that the concrete floor was sealed with a water based coating.
- How to avoid having to remove a concrete sealants where possible
The typical rule of thumb sees a like to like approach when re-applying sealants and thus avoiding having to remove the original coating. A solvent based sealer can be re-applied to a concrete surface originally sealed with a solvent based product and a water based product reapplied to original water based coatings. Conversely so, one cannot stress enough that a solvent based sealant cannot be applied to a surface previously sealed with water based application and vice versa.
The reason why one can only re-seal concrete surfaces with a like: like approach is because of the chemical reaction that takes pace when solvent and water based products come into contact – even once they have dried. When applying a solvent based sealant to water based coatings, the solvent solution “eats away” at the water based sealant creating an unsmooth and blistered or flaky surface. This result in a flawed application and one that fails to adhere to the surface it is applied to.
If a water based sealant formed the base coat to any concrete surface that you now wish to seal with a solvent based coating the water based sealant will need to be removed by way of chemical etching, high pressure washing or mechanical abrasion.
If a solvent based sealant was originally applied that you now wish to coat with a water based product, the solvent based sealant must be removed using a Xylene stripper or a high pressure wash.
Smelly, messy and hazardous, stripping off cement sealants can leave your equipment soiled, your skin burnt and the condition of the area that you are working on damaged and marred.
Whether making use of caustic chemicals or attempting to sandblast or grind away at concrete floor sealers, the original surface can be left disfigured, the aggregate exposed and a mucky mess remaining behind to have to clean up after. Where possible try to avoid this unwelcomed job but where no other choice is available be sure to make use of high quality products, contract only the best in the business, don’t cut corners and keep the clean up as environmentally friendly as possible.