Before we get straight to the solution, we must first see the reasons that cause the concrete sealer to bubble.
When sealer is applied too heavily, the air that is displaced through the surface cannot escape and it leads to the formation of bubbles in the sealer surface. Bubbles can also be created in the sealer if the application is done in hot weather. Also, if the concrete faces the direct heat of the Sun.
In this blog, we will talk about the tips to fix the formation of bubbles.
The solvent-based acrylic concrete sealers are designed to enhance, darken, and give shine to decorative concrete surfaces. However, if these are not applied correctly or are overapplied, issues like bubbles start to form. This situation typically happens to stamped concrete or smooth decorative concrete surfaces.
The Process
When a solvent-based acrylic sealer is applied, some sealer penetrates into the porous concrete. If the application is too thick or if a lot coatings are applied, the solvent does not evaporate before the sealer dries up. Whenever that happens, the solvent gets trapped and finally it creates enough pressure that it finds its way out, therefore bubbles are formed.
Tips to Applying a Solvent Acrylic Sealer
- Follow the directions.
- Do not over-apply.
- The porosity of concrete differs. The more porous the concrete is, the more sealers will be applied.
- If you apply more than one coat, allow the coatings to dry thoroughly between applications.
Remedy for Bubble Formation
- Sweep or clean the dirt and grime gathered.
- Wait till there is no direct sunlight.
- Apply solvent to reset the sealer and cure the bubbles.
- Allow the sealer to sit overnight and let it dry properly.
Important Note: The bubbles might come back. However, in many cases, the above steps will fix the issue. If this does not solve the problem, strip off the sealer and start again.
Prevention is Better Than Cure!
It is always better to know the reason that leads to the issue. Know why decorative concrete sealer issues occur so that you are able to prevent them from stamping, staining and other decorative concrete projects.
When a concrete sealer does not look or perform as expected, the cause can be traced back to over-application or application in not ideal condition or even a build-up of multiple coating – as already discussed above.
The Application
Concrete sealers are best applied in two thin coats. The first coat of sealer acts like a primer. The concrete will not look very attractive after the first coat. The second coat will provide an even finish, make it glossy and also enhance the colour.
The process is time consuming and can be taken up by the professional concrete sealing contractors like Tuff Build in Melbourne.
The process requires more time and patience to apply two thin coats of sealer instead of one heavy coat. The solvents keep the air clean, sealers based on these solvents dry much faster than the traditional solvent based products. This is the reason, application of the solvent based sealers can be tricky until the contractor is accustomed to fast dry and the changes occur in the application methods.
It is important to follow the rules regarding the thickness of application and apply sealer in the proper environmental conditions. These aspects are taken care of by the professional concrete sealer applicators just like we have at Tuff Build, the concrete sealing contractors in Melbourne.
Will Concrete Sealers’ Bubbles Go Away?
The answer is yes, concrete sealer’s bubbles definitely go away. For solvent-based sealers, blisters and other surface defects can be removed with a solvent bath which includes wetting the surface with acetone or xylene. This sometimes work the best with water-based sealers, but first of all, testing is recommended.
Other Problems
Solvent-Based Sealer Turned White is Peeling or is Flaking Off?
There are two main contributors to blushing or whitening of a concrete sealer. The first is the wet application to a concrete surface, or fresh concrete that still contains bleed water.
If any of the above two situation happens, the sealer will not bond to the concrete surface but will float on a trapped film of water. The second cause of sealer blushing would be over-application.
Thick coats and overlapping will cause moisture to get trapped under the sealer which will de-bond from the concrete. When this happens, the sealer fails to turn white. But the surface turns while only because of moisture and air.
Water-Based Sealer is White or Powdery
Solvent-based sealers dry simply through evaporation of the solvent carrier.
The process of drying of water-based sealer is complicated and is significantly affected by humidity and temperature of the environment.
The process of drying water-based acrylic sealers is called coalescence. In this process first the water, and then the coalescing solvent evaporates and fuses together the acrylic particles, thereby forming the sealer film.
If the temperature during application of concrete sealer is too low or humidity is too high, the coalescing solvent will evaporate before the water does and the sealer get dry white or powdery because the latex particles will not stick together before drying.