How to use concrete polishing pads?

Not only are concrete floors durable, but they also have a raw, industrial charm that can be enhanced by the art of polishing. Concrete polishing pads are specially designed abrasive tools that are essential in the process of refining and polishing concrete floors. In this article, we take an in-depth look at the basic steps and techniques for using concrete polishing pads to transform concrete floors into stunning polished surfaces.

Clean and polish the floor

1. Prepare the surface: Sweeping the floor with a broom or washing it with water will effectively remove surface contaminants and create a clean canvas for subsequent polishing steps.

2. Preliminary polishing with 30# diamond cup wheel: After the floor is cleaned, the next step is to use a 30# diamond cup wheel to polish the original floor surface. This initial grinding process is used to address any imperfections, unevenness, or rough areas, preparing the floor for further finishing. The use of diamond cup grinding wheels ensures effective material removal and surface smoothness, laying the foundation for perfect surface treatment.

3. Refining with 50# diamond cup wheel: After cleaning up the laitance produced by the initial polishing, replace the 30# diamond cup grinding wheel with a 50# diamond cup grinding wheel to continue polishing and improve the smoothness and degree of the original floor surface.

4. Use diamond resin grinding disc to expose cement pores: After completing the cup-shaped grinding wheel grinding process and cleaning the grinding surface, use a 50# diamond resin grinding disc to fully expose the cement pores. This exposure helps increase the absorption of the hardener, which is critical to improving the strength, durability, and overall construction results of the floor. Sand the floor 1-2 times with a resin disc to ensure pores are thoroughly exposed and to optimize the floor for hardener application.

Notice:

• Floor hardness and hardener: If the ground is not hard enough, a curing agent must be used to increase the strength of the ground before grinding.
• Repair of holes and cracks: Any large holes or cracks present in the floor should be thoroughly repaired and allowed to dry before grinding.
• Eliminate steel nails or bolts: If steel nails or bolts are present on the exposed surface, they must be cut and the area subsequently sanded.
• Moisturize the floor surface: Using a small amount of water, moisten the floor surface to the point where there is enough moisture but no visible water on the surface.
• Cross-grinding technology: During the grinding process, it is important to ensure that the machine performs cross-grinding in both horizontal and vertical directions.
• Cleaning and smoothing during grinding: After each horizontal and vertical sanding, it is crucial to remove dust from the floor. Additionally, if any area is found to be insufficiently ground, it should be processed further until a smooth and even surface is obtained.
• Leveling and necessary grinding times: The initial leveling process is typically performed 1-2 times, but the actual number required may vary based on ground conditions.

Spray concrete sealer and curing agent (first pass)

After removing the laitance and allowing the floor to dry thoroughly, you must ensure that the surface is free of dust, debris, and any other contaminants.

Concrete sealing and curing agents should be mixed with water in the recommended ratio of 1:4 or 1:5. After the solution is prepared, it should be sprayed evenly on the ground.

To help absorb the sealant and curing agent, use a long-bristled brush to brush back and forth over the surface. This action helps ensure that the agent is evenly distributed and effectively penetrates into the concrete, laying the foundation for increased durability and strength.

Notice:

• Even applied in the first pass: It is crucial to apply the hardener evenly in the first pass, ensuring the surface remains moist to recommended standards.
• Dilution of excess curing agent: When the curing agent becomes slippery and thick, an appropriate amount of water should be sprayed onto the ground. Then, push back and forth with the brush to effectively dilute the excess agent and promote secondary penetration into the ground.
• Adapt to ground conditions: The soaking time is generally about two hours, but the application time should be adjusted according to the specific conditions of the ground. Factors such as temperature, humidity, and the porosity of the concrete can affect the absorption and penetration of the curing agent, so flexibility is required.

Finely grind the ground

After allowing the material to penetrate for at least two hours, it is important to polish the floor using a diamond resin abrasive disc.

The start of grinding should coincide with the point when the material has fully reacted with the concrete and reached an 80% dry state. It is important to note that the surface should not be completely dry at this stage. In the absence of sufficient humidity, it is recommended to use an appropriate amount of hardener.

Notice:

• Even and comprehensive grinding: Where corners and other difficult-to-sand areas exist, using a hand sander provides a practical solution.
• Repair micropores and microcracks: The grinder’s speed is carefully adjusted to approximately 800-1000 rpm, optimizing the grinding action to account for defects and irregularities. Meticulous grinding of the slurry, accompanied by slow pressing and penetration, can effectively resolve and dry the slurry within micropores and fine cracks, ultimately achieving comprehensive repair and strengthening of the surface.
• Cleanse after polishing to enhance absorption: After each round of polishing, a thorough cleaning with an industrial vacuum is essential to ensure the floor is perfectly prepared for subsequent treatments.

Spray concrete hardener again (second pass)

After the laitance is cleaned and the ground is completely dry, spray the concrete sealing and curing agent again and keep it moist for about two hours. During this period, use a long-bristled brush to push back and forth to help the ground absorb it.

Notice:

The second coat of curing agent should also be sprayed evenly, and the surface should be wet as a standard.

Use the dust pusher to push back and forth evenly, gradually adding layers to ensure that the ground is fully moistened and absorbed within two hours.

The soaking time of materials is generally about two hours, and the actual operation can be adjusted according to the actual conditions on the ground.

Finely grind the ground

Two hours after the material has penetrated, use a 400# diamond resin grinding disc to polish it 1-2 times, then use an 800# or 1500# diamond resin grinding disc to fully polish and polish the entire base surface.

Floor polishing

After carefully cleaning the floor surface, the next step is to apply the polish evenly. This is usually done using a sprayer or watering bottle, which spreads the polish evenly over the entire surface. Then use a clean mop to further ensure that the polish is evenly distributed for consistent coverage on the floor. Allow the polish to penetrate for approximately 20 minutes. After the penetration stage, the actual polishing process begins. Using a diamond grinding disc with a grit size of 1500# or above is critical to obtaining a finely polished surface. These discs excel at smoothing out imperfections, refining surface texture, and enhancing the overall appearance of your flooring.

Notice:

• Optimize polishing equipment: Adding a counterweight to the machine and adjusting the grinder speed to the highest setting can significantly increase the efficiency and effectiveness of the polishing process.
• Consider dry or wet polishing: Floor polishing can be carried out using dry or wet methods, providing flexibility and adaptability depending on specific requirements and environmental factors.
• Utilize high-speed polishing machines: Using a high-speed polisher equipped with a scouring pad can significantly improve the quality and efficiency of the polishing process.