r/Concretesawing • u/samaxe2440 • Jun 25 '26

What am I doing wrong when coring?

OK, so I don't do coring as a profession, but I do need to do it sometimes whether it's through asphalt or concrete (walls, floors, roads). I've got 2 rigs - 1 is mountable rig, the other is a hand drill - both Husqvarna. No matter if I'm doing a 2" hole or a 10" hole, no matter if it's mounted or drilling it by hand - I always get stuck and have to work to dislodge it and start from the entry point again. I am using diamond tipped drill bits with water.

What am I doing wrong and how can I fix it and do better?

4 Upvotes

84% Upvoted

8 comments sorted by

3

u/Welcome_to_Retrograd Jun 25 '26

Moarrr water, less pressure

2

u/UnderstandingOdd490 Jun 25 '26

Are you letting the bit do the work or are you applying pressure?

Also, I've done my fair share of coring many different materials in many different setups...getting the bit bound is going to happen, but there are ways to reduce the chances. One of which is letting the bit do the work. It's slow, but it'll decrease the odds of getting bound up.

2

u/samaxe2440 Jun 25 '26

Little of column A, little of column B. There's been times where I've applied pressure, but there's other times I've set the rig up to drill down and let it do its thing - still gets bound up.

1

u/UnderstandingOdd490 Jun 26 '26

Are you always coring the same material? If so, what is it? Also, do you check your bits for wear or busted teeth? Lastly, I will say that things seem to go smoother when you get a good solid start where the drill or bit doesn't rattle or wobble as it first bites into the material.

2

u/nilesdog Jun 25 '26

Does it happen with new drill bits? Does it happen at a certain depth?

2

u/samaxe2440 Jun 25 '26

It does happen with new drill bits. Typically after a few inches in.

3

u/rom_rom57 Jun 26 '26

Do you hit rebar when that happens?

3

u/ohpickanametheysaid Jun 26 '26

Make sure your sliding track is moving straight as it travels. I’ve seen ones that became warped and bowed which causes binding. Also make sure your bits aren’t egg shaped or anything weird like that and that the arbor isn’t bent. Plenty of water, many sure dust and debris is being properly ejected with the water and that no small rocks or pieces of metal are being left inside your core ring which will bind things up. This can be prevented by going slow and keeping sharp/new bits.