Concrete Vs Metal Bond Types
Concrete surfaces can vary widely and will determine if hard or soft bond diamond cup wheels are required. Generally this selection will be made by trialing the cup wheels. Hard concrete results in a soft non abrasive dust so a soft bond disc is required to help expose the diamond particles. If you find the machine is grinding too slow try a softer bond grinding disc. The opposite applies for grinding softer concrete. Use a hard bond disc to prevent unnecessary disc wear. If you find the disc is wearing too fast switch to a hard bond disc. You can also visually inspect the disc and if too little diamond is exposed or the surface is getting hot then switch to a soft bond disc or a disc with fewer segments.
Choose the right grit size
Diacutex diamond cup wheels start with the coarsest disc (10 grit) and works through to the finest, 400 grit. Generally the concrete floor preparation process will start with a 30 grit disc and progress incrementally through to 80 grit. A finishing pass using a 150 grit disc will prepare the surface for sealer application. Most customers are satisfied with the result at this point.
For fine grinding (sometimes called "polishing"), the bond should be harder and the diamonds' quality can be lower, as in this case the diamonds can last longer and a hard bond can also help the precision of the process.
Sintering Vs Silver Soldering
There are two main manufacturing techinque on the diamond cup wheels: sintering and silver soldering.
The sintering cup wheels use the cold pressing method, press the diamond segments to their forms directly on the grinding wheel's body, and let the segments connect with the wheel's body via teeth, slots or other manners. Then, put the grinding wheels into sintering furnaces to sinter without press. As it is no press sintering, so the sintering cup wheels don't have long lifespan, it is only for general use.
The Silver soldering cup wheels use the hot pressing method, the hot pressing method is to directly sinter the diamond segments in molds under a certain pressure in the dedicated sintering press machine, and then fix or connect the diamond segments onto the grinding wheel’s body via high-frequency welding, laser welding or mechanical mosaic method.