i am cutting a hole in a concrete wall with a rotary cutter. should i chisel away the core, or keep it intact

I am using an SDS drill, a 127mm cutter with pilot drill, and am using WD40 as the cutting fluid. progress has stopped, so should i chisel at the “core”, or simply keep the core intact? any ideas about a better cutting fluid would help !! thank you
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WD40 is a lubricant and will slow the cutting, not accellerate it.
This is especially true if you’ve hit re-bar.
Use water to cool the bit and carry away the spoil.
your first reply sounds good to me, water as a coolant and don1t break away the core or you will have problem`s
Your choice of cutting fluid baffles me, just use a little water in a spray bottle to hold down the dust. Also you should have a dust mask on, Silicosis is a bad form of cancer caused by concrete dust. Put the WD40 down. Use a shop vac to draw out the loose debris. and break the core out as you go or your bit will bottom out. Also you should have a Pilot hole drilled all the way through. You should reverse and drill from both sides of the wall so that you don’t SPAWL the surface when you finally break through.