Core Drilling

A core drill is an incredibly powerful tool for boring holes through various materials, such as concrete, reinforced concrete, brick, block, stone and masonry. It can be of a great help if you know how to use it properly and take proper care of it. During the process, you always need to have in mind what you are drilling and in what conditions. There are some general rules for certain materials that you have to follow if youwant to do a good job and keep your machine undamaged.

Contrary to what is believed to be true, if you are drilling with a wet diamond core bit, it is better to use less water than more water. Less water enables the diamonds to grind away the concrete. On the other hand too much water pressure washes away the concrete grit and prevents new diamonds from being exposed. For the best results, apply water until the slurry mixture resembles a heavily creamed coffee. A proper slurry mixture will help the grinding process by keeping the core bit cool. The diamonds will remain exposed and stay in contact with particles in the slurry mixture.

It is very important to maintain steady, even pressure. Correct pressure will help ensure maximum core bit life. Too little pressure can cause the diamonds to glaze over. Inconsistent pressure or pecking will cause the drill to glaze over. Too much pressure will overload the drill, causing damage to both the core bit and the drill motor. Set your motor to the appropriate revolutions per minute (RPM) to grind properly and prevent the diamond segments to be glazed. When set at the ideal surface speed, the core bit will cut efficiently. For example, smaller core bits require higher RPMs. If set too slow, the job will take too long and the drill may glaze.

To sustain the correct drilling speed, you need adequate power. Larger core bits require more power. If the drill is underpowered, it will lead to overheating during operation and instantly damaging the tool. Most core drills are electric-powered. When drilling, listen to the electric motor. When in use, the pitch of the motor will lower. If the motor begins screeching or the mechanical clutch slips, reduce feed pressure immediately or you might damage it. Core drills are also available in pneumatic and hydraulic versions for special applications in a variety of environments, including underwater.

Core drilling for minerals normally consists of drilling long sections in bedrock before reaching the ore horizon, making the process more time consuming and expensive than necessary. In addition, natural deviation can change the drill path and reduce the value of the information gained from the borehole.