Grinding and polishing are important steps in surface preparation to achieve high-quality outcomes. The purpose of grinding and polishing is to correct and smoothen surface damage left by cutting. Soft surfaces are easier to grind, but hard surfaces require more grit. The pressure required for grinding needs care and a thorough understanding of the direction, chemical reactivity, and impact of relative velocity distribution. Hard surfaces require more pressure, for instance, but excessive hardness can also lead to subsurface damage. Knowledge of accurate velocity distribution, application of speed and pressure are all important for effective grinding to minimize surface damage and optimize polishing results.
Polishing is an important and complex step to remove deformation from fine grinding and acquire a smooth, reflective surface. The quality of the cloth, polishing pressure, speed, duration and abrasiveness of the cloth, all need to be considered to get satisfactory results. Below are a few common mistakes to avoid for a good-quality, smooth, shiny surface.
#1: Incorrect Bond for Concrete
The wrong tools can ruin a metal surface. That affects production rates and the quality of the outcome. Diamond products (in paste, suspension or spray forms) are the first choice in metallographic polishing for cutting because of their exceptional hardness.
Diamonds are available in two shapes for this purpose: Polycrystalline (P) and monocrystalline (M). Polycrystalline diamonds are better for uniform surfaces on rough materials. Block-shaped monocrystalline diamonds allow high material removal and a more variable scratch pattern that is best for polishing.
Grinding hard concrete leaves finer dust than polishing soft concrete. The dust interacts with the matrix of the diamond tool to wear it down and expose more diamonds as you grind. The wrong tooling on the wrong surface results in a disaster. Nothing may happen when the machine is run because the diamonds may not cut, especially on hard concrete. Or else the diamonds can cut rapidly, but wear them out fast so you lose money on expensive diamonds that have not done the job well, leading to big losses. The wrong tool can wear out the tool too.
It’s important to find the right balance to increase productivity, save money and optimize results by knowing the hardness of the concrete and how each bond works on them. Then pair the appropriate diamond with the concrete for best results. Here’s the rule of thumb:
- Soft concrete needs hard bond diamonds
- Medium concrete needs medium bond diamonds
- Hard concrete needs soft bond diamonds
- Very hard concrete needs very soft diamonds
#2: Grinding Too Fast
An inexperienced worker can run the grinder too fast at a high speed, hoping to accomplish more in less time, but this can overheat and glaze over the diamonds, especially on hard concrete, so cutting will not produce the required results. Here is where a heavier machine and knowledge of the right diamond options make a difference. Smaller machines and a single round diamond give more pressure than double round or single rectangle, so the cutting is faster. Larger machines perform better with double segment diamonds because it grinds a larger space better.
#3: Selecting Cheap Diamond Options
While selecting the diamond tooling, price should not be the only factor. Cheap, poor quality diamonds wear out fast, scratch the floors, give inconsistent results and come with no product warranty from the vendor. Reliable vendors stand behind their products, save you money, time and increase productivity with the right tools.
#4: Inaccurate Floor Inspection
Metal bond diamonds can grind any polish on all kinds of surfaces from glass, brass and steel and more, but the material should not be raised above the floor surface (above grade). Above grade floors need hand grinding to level them before grinding the concrete. If the floor is not well inspected, the diamond segment and machine can get damaged.
#5: Knowledge of the Process
It is important to be aware of the outcome before selecting the tools for grinding and polishing. Do you want a cream polish, heavy aggregate polish, salt and pepper finish? Are you removing epoxy coatings, ceramic tile or VCT from the floor? Choose the diamond for the polishing process accordingly. Remove scratches as soon as you spot them while polishing for a flawless finish. Make sure the end result meets your customer’s expectations.
Need to reach out to the right grinding and polishing experts for the best results? Reach out to us at Royal Coating & Supply, Alberta, for solutions for all of your decorative concrete needs. Our experts can help you with anything from material selection to concrete coating, renting or buying the right equipment, guidance on the right tooling, and all the consumables and supplies you will need to finish your project perfectly.