Core Drill Maintenance and Storage
Core drill assemblies and accessories are made to withstand the wear and tear that happen in construction environments. But even tough tools will need a periodic inspection and light-duty maintenance from time to time. By checking through the drilling equipment prior to the start of each project, you’ll save your crew some trouble.
Perform checks on all extension cords at regular intervals and document your inspections. Replace all items found to be damaged.
Visual Review of General Condition
The starting point of a good maintenance program is a visual check of the equipment’s general condition both after completing a coring project and before starting a new one. Common concerns include misalignment or binding of moving parts, dents, broken surfaces, and a worn condition of bits and tools.Readable Safety Labels
Along with the visual inspection of your core drill assembly, ensure that all warning labels and name tag stickers are legible and properly placed on all equipment. Replace any that become worn or damaged.Electrical Equipment
If you are using corded core drills, it’s important to check the unit’s supply cord and plugs at regular intervals. If either item needs repair, you should have it replaced with the manufacturer’s part and installed by a qualified specialist.Perform checks on all extension cords at regular intervals and document your inspections. Replace all items found to be damaged.
Hydraulic Hoses
A thorough precheck of your assembly’s hydraulic hoses will prevent possible delays, leaks, and safety issues. Check your tool’s manufacturer notes for the type of hoses you should be using. It’s always best to use only certified non-conductive hoses when drilling near electrical conductors.Maintaining Core Drill Bits
An important aspect of successful core drilling is bit maintenance. Extended use, poor handling, or improper drill rates can lower the bit’s service life. And while lower bit service life is a concern, your real cost is lower productivity and often damage to the core drill assembly.Also make sure that your toolbox has a wide array of drill bits and shanks so that crews are prepared for unexpected material changes. For example, it’s common to encounter two types of substrates when drilling through a masonry wall.
During inspection, ensure that all bits are sharp. When the tool is packed up from a job, check the job report or ask the operators if the rate of penetration seemed proper. When penetration notably slows, your bit may need to be sharpened. Most diamond impregnated core bits are designed to be self-sharpening, wearing away host material and exposing newer diamonds. Learn how to properly judge this wear.
Have a bit measuring gauge on hand. These useful tools take the guesswork out judging bit wear. They provide a numerical result (mechanical or digital) that will indicate a bit’s wear.
Most core drilling operations will apply just enough pressure to the bit allowing the optimal coring-to-penetration rate. Most units set the pressure to about 15% to 20% of the bit’s weight on the bit. These control units also automatically adjust the controller to coordinate rotation speed with the downward pressure.
Weight-On-Bit Controls (WOB)
On those rare occasions that you might be coring deep, or in bedrock, you will need to monitor the amount of pressure placed on the bit. This calculation is referred to as Weight on the Bit (WOB) representing the total amount of downward force exerted at the point of coring.Most core drilling operations will apply just enough pressure to the bit allowing the optimal coring-to-penetration rate. Most units set the pressure to about 15% to 20% of the bit’s weight on the bit. These control units also automatically adjust the controller to coordinate rotation speed with the downward pressure.