Slippery Rock Gazette

Frederick M. Hueston

Stone Forensics

Are you tired of your diamond abrasives wearing out too fast? Whether you’re a stone restoration contractor, an installer, or a fabricator, the cost of your materials will impact your bottom line. The price of diamonds, like everything else, is on the rise. Proper selection, use, and care of your abrasives will save you a significant amount of money over the course of time. Here are ten tips for getting the most use out of your diamonds: 

1. Choose the right diamond.

When it comes to diamond selection, consider both the type of material and the task. For example, a metal bond diamond would be the most appropriate choice for sandstone and certain limestones that are very abrasive, because a regular diamond would wear out in just a few square feet. Be sure to use the right diamond for the task, too. Floor diamonds are different than diamonds used in edge polishing. Choosing the right type of diamond is extremely important because diamond selection directly correlates with the amount of use the diamond will provide.

All metal bond and resin bond tools work by controlled erosion. You must match the matrix, the material that holds the diamonds in place, to the material and the tool. When all factors are addressed you should get the diamonds and matrix wearing in harmony. If the bond is too hard the diamonds wear down prematurely and the tool stops cutting. If the bond is too soft the diamond is ejected before it is worn out and you lose tool life. Diamond tool manufacturers will tell you the hardness of the bond so that you can make a good, educated choice.

2. Don’t buy cheap diamonds.

You get what you pay for when it comes to diamonds. The stone and tile industry has been flooded with cheap bargain diamonds that may do the job, but not for long. These cheap diamonds will end up costing more in the long run. Buy good quality diamond tooling. Even though they cost more, they have more value, based on extended usage.

In a production application you should do a complete value analysis. There are several factors to consider:

• Price. Almost never is the cheapest best.
• Speed. Because time is money.
• Tool life directly impacts price.
• Quality of finish can greatly impact time.
• Operator skill level can greatly impact quality and time.

The goal is to find the least cost per cut or per square foot. For example a quarry needs to know the overall cost to produce their material in order to know what to charge the distributor.

3. Break in new diamonds, if applicable.

Brand-new diamonds may have a thin resin coating on the surface. The diamonds will not cut properly if this coating remains intact. Check with the manufacturer whether breaking in their diamonds is required. If so, break them in by running them quickly on a rough surface, such as concrete block or the back side of a rough piece of granite. Removing the resin coating exposes the diamonds for polishing.

This generally only applies to polishing tools, as most diamond tool manufacturers grind down the metal bonds to expose a good first layer of diamond.

4. Properly expose diamonds on the first use.

Don’t force new diamonds to cut. Begin with little to no weight on your floor machine. After several minutes, add weight. This process not only helps break the diamonds in for polishing, but also inhibits premature wear.

5. Rotate diamonds.

Just as the tires on a vehicle should be rotated so that they wear evenly, rotating diamonds on your drive pad may allow you to get more use out of them. Number the pods on the drive pad and number the diamonds. For example, if diamond #1 is on drive pod #1, then for the next use, diamond #1 should be on drive pod #2.

6. Use a diamond lubricant. 

Diamonds will wear rapidly if they are not kept cool and well lubricated. Consider using a diamond lubricant (such as Dr. Fred’s Diamond Lubricant), created specifically for this purpose. 

A diamond lubricant will also keep harmful slurry suspended and aid in slurry clean up.

Make sure you know whether the tools are made for wet or dry use. Important rule. Wet tools can only be run wet but dry tools can be run wet or dry. Improper use can destroy a set of pads quickly.

7. Avoid high speeds.

Overheating can cause the diamonds to glaze over, and then they will no longer cut. Keeping diamonds cool becomes increasingly difficult the higher the speed. Avoid high speeds. For hand machines, do not exceed 5000 rpm. Floor machines are generally 175 to 300 rpm, so speed should not be an issue. 

Note: Diamonds can be re-opened by using the same break-in process as brand-new diamonds with resin coating, but be aware that each time a diamond is glazed over and reopened, premature wear occurs.

All diamond tools have recommended RPMs. If you do not have that information, contact the manufacturer. Many contractors do not realize that slower RPMs actually allow each individual diamond particle to cut faster, as they have the opportunity to “scratch” deeper into the material. This can increase production speed.

8. Avoid trouble spots in and around your work area.

Try to keep diamonds on the surface of the work area. Overlapping onto wood, metal or other materials will cause the diamonds to clog and rapidly wear prematurely. Also,  avoid sharp edges and lippage, which can quickly wear resin-backed diamond tools.

9. Rinse diamond tools after use. 

If slurry remains on diamond tooling long enough, it hardens as it dries, just like wet concrete. Hardened, dried-on slurry can be abrasive on diamonds. So, after each use, rinse diamonds in clean water and use a soft scrub brush to remove slurry from the crevices. Cleaning diamonds in between jobs can double the amount of use they provide.

10. Allow clean diamonds to fully dry before storing them. 

The best way to dry diamonds is to wipe off the excess moisture with a clean, dry towel and then let them air dry. Diamond pads that are stored wet can grow mold and mildew, and moisture can break down the glue holding the backing. Make sure diamonds are completely dry before you store them. The best way to store diamonds is on a board in your shop, or in a toolbox on your truck. Avoid storing diamonds in plastic bags, because even a small amount of trapped moisture can still cause damage.  

Follow these tips to get the most use out of your diamonds and keep the cost of your materials down, which will improve your bottom line.