Diamond Core Bit Drilling Tips

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Always secure the drill rig with a mechanical anchor, vacuum system, or by using the jack screw. NEVER stand on base and drill without anchoring.

Level the drill rig by use of the base leveling screws, and a small level attached to the column permanently or by a magnetic strip on the level. This procedure will insure a perpendicular hole.

Never let the bit spin in the hole without applied pressure. This will cause the diamonds to round off and the bit segments will heat and glaze over.

Turn on water before starting the drill motor. Otherwise, the water jacket seals heat and becomes brittle, losing water.

When your bit encounters steel (rebar), relax pressure about 1/3 and allow the bit to cut at its own rate. DO NOT PUSH THE BIT. Some operators turn the water down after exiting the steel to sharpen the bit. If you engage in this practice, don't forget to turn the water back up once the bit is sharpened.

When drilling high psi concrete or concrete with very hard aggregate (i.e. river rock, flint rock, etc.) the bit will sometimes glaze over. To open or redress the bit, do one of the following:

  • Decrease water about 1/2 for a few minutes and as the bit starts to increase speed, gradually increase water until flow is back to original state.
  • Pour masonry sand into the serf, and then follow the above directions.
  • Add sandblast media such as "Black Beauty" to the serf and follow above directions.
  • Drill bit into cement block, soft vitrified grinding wheel or cinder block. Repeat procedure until the bit is open again.

When finished drilling, turn the water down very low and back the core bit out of the hole with the motor running.

Drilling is actually more of a grinding operation with the small diamond going around, always use high speed and light pressure, NEVER push, lean, or force the core bit.

Use high speed and very light pressure, never lean or push on the drill motor as this could heat up the brushes and armature of your drill motor.

Always keep your amp meter in the green, NEVER apply pressure and "crank" down pushing the motor into the red. Use finger tip amount of pressure when core drilling.

When drilling, use enough water to produce a choclate milk type slurry, not too thick and not clear water, using enough to effectively flush out the cuttings.

When starting your dry core drilling hole, use Dynatech's starter bit assembly for the first 1/2" for easy hole starting.

When dry drilling always work the core bit in and out of the hole to remove cuttings.

When drilling with a core rig, always adjust the 4 leveling bolts to pull against your vacuum or anchor - this will steady your position and help secure your rig.

When using Dynatech's dry Vacuum core bits, always use a strong shop vac to remove cuttings and keep the core bit cool.

When wet drilling in concrete with rebar, slow your drilling speed when going through the rebar, then speed back up for the rest of the concrete.