Wet Core Drilling Fault Finder

Symptom

Cause

Remedy

Why is the core slow in cutting

·         The concrete is too hard for current set up.

·         Possibly too many segments and not enough power.

·         Change the set up by either changing the drill motor to provide enough power

·         Reduce speed of the motor

·         Change the number of segments (Snap one off if you need to)

Why does my core no longer cut

·         Diamonds have glazed over.

·         This could be due to not enough power and too much diamond and the diamonds not being able to fracture down and continue cutting

·         Evaluate the amount of power to the diameter of the core.

·         Hand held machines 1500w to 1900w max diameter 100mm

·         Hand held machines 1900w to 2200w max diameter 150mm.

·         Rig mounted motors 2500w min diameter 50mm max diameter 250mm.

·         Rig mounted motors 3000w min diameter 75mm to max diameter 500mm

These are all general guidelines but each job must be considered separately.

Some of the segments of my core have turned inwards

·         Lack of water

·         See attached water flow requirement for each diameter.

Cracks have appeared in the barrel

·         These are stress fractures due to lack of water, diamond glazing and not cutting

·         Ensure you have the right amount of power for the diameter.

·         Switch to mains water if using a water bottle.

Water bottles are nominally only 10 Litres see water flow requirement attached

Core keeps jamming in the hole

·         Core not running straight (particularly when hand held)

·          Snagging on material either re-bar if handheld or sub base (broken stones )

·         Switch to using a drilling rig, to ensure the core stays straight

·         Reduce the speed of the drill and allow it to cut through the bottom slab and sub base slowly.

Loss of segment

·         Could have snagged inside

·         Lack of water

·         Misused by operator

·         Back the core off and try and get the segment out.

·         Switch to mains if previously using a bottle.

·         Check for any other damage as the core may have been dropped/knocked on site.

Segments glazing

·         Operator hitting particularly high levels of steel reinforcement.

·         Back the core off.

·         Fill the hole with sharp sand

·         Turn motor to the slowest speed

·         Let the core run the sand to create a grinding paste to resharpen the diamonds

·         Keep constant water supply and not too much pressure on the drill.