Core drilling tools for bolt replacement

That's helpful! Thanks for posting.

Is there a good glue-in that you put in a 16mm hole?

bmdhacks wrote:

That's helpful! Thanks for posting.

Is there a good glue-in that you put in a 16mm hole?

8mm twist bolt, the best glue in!

Jim Day wrote:

I had success removing 1/2" powers bolts with a 16mm bit today.  I thought I was done when the bit chipped on the first bolt, but I think it actually made it better!

Does anyone have more information on the inside diameter of the larger bits? Im looking for a bit to remove some 14mm single leg glue ins. 

Seems like its generally ~3-4mm increase from ID to OD. You think Id be safe with an 18mm bit to remove a 14mm bolt? Would there be a better adapter system for larger  diameters / longer bolts?

Alec Baker wrote:

Does anyone have more information on the inside diameter of the larger bits? Im looking for a bit to remove some 14mm single leg glue ins. 

Seems like its generally ~3-4mm increase from ID to OD. You think Id be safe with an 18mm bit to remove a 14mm bolt? Would there be a better adapter system for larger  diameters / longer bolts?

I got a couple of the 17mm to remove botched glue ins. The ID is 14.7mm which should work for you, and leaves a hole that will fit the 8mm twist bolts.  They only have a ~92mm drilling depth which isn’t enough for wave bolts, or many other glue ins. Possible longer ones are available, but I haven’t looked. 

Every bit I've bought (12, 13, 15, and 16) has had a thick spot on the ID.  This is a picture of the D16, which has a 12mm ID on the narrowest portion but 13mm everywhere else.

It fits a 1/2" wedge bolt (up to the clip) and 12mm sleeves, but the 1/2" powers sleeves I could tell it was tight and I only went half an inch over the sleeve, I had to funk out at that point.  I'll probably plan on 17mm bits for 1/2" sleeves in the future.

Thanks Peter and Jim, very helpful!

Peter Thomas wrote:

I got a couple of the 17mm to remove botched glue ins. The ID is 14.7mm which should work for you, and leaves a hole that will fit the 8mm twist bolts.  They only have a ~92mm drilling depth which isn’t enough for wave bolts, or many other glue ins. Possible longer ones are available, but I haven’t looked.

Aliexpress has 17mm 153mm length bits (105mm core depth) available through the Ali app.  They are just long enough to get the shank depth of a wave bolt.

I think that even if you have a centimeter or two embedded glue depth left after core drilling 92mm, you could mangle/leverage out a wave or twist bolt with a nail puller pretty easily.  I once leveraged out a 100mm twist bolt that was only installed halfway before the A7 glue set, it took 15-20 minutes with a nail puller

Jim Day wrote:

I think that even if you have a centimeter or two embedded glue depth left after core drilling 92mm, you could mangle/leverage out a wave or twist bolt with a nail puller pretty easily.  I once leveraged out a 100mm twist bolt that was only installed halfway before the A7 glue set, it took 15-20 minutes with a nail puller

Im confused how youd core drill a glue in, but still have the eye to pry out?

Alec Baker wrote:

Im confused how youd core drill a glue in, but still have the eye to pry out?

Good point :P

I would try to cut off the eye with a hacksaw, core drill, then wiggle the stubs out with vice grips.  I haven't had to try yet, but am interested on other suggestions 

Lol no worries, just wanted to make sure I wasnt missing something obvious

I managed to core drill a twist bolt. Im sure with practice it would get easier, but this took me 2L of water and over an hour. 

Red neck core drilling plus Hurley Sr. Style pulling tool has been used in the past for Wave bolts. I wonder if that can be a standard method for most glue ins?

I have one of these new style thin wall core drilling rigs but find that Red neck core drilling gets the job done. Only requires a few small diameter bits beyond the standard tools required. Consequenty the thin wall core drill has only been tested in the garage. 

I have not been removing glue-ins though.

I've read about using "redneck" core drilling on wave bolts, but I haven't read anything about doing that with twist bolts.

After using the thin wall core drill bit as deep as it would go, I still needed to use the "redneck" core drill method to get the last bit of epoxy to disengage, but I could do that without widening the entry hole and I was able to pull out the rest of the bolt with needle nose vice grips. 

Alec Baker wrote:

I managed to core drill a twist bolt. Im sure with practice it would get easier, but this took me 2L of water and over an hour. 

Did you use D16 or D17 bit?

D16. It bound up quite a bit but i think that was mostly poor drilling on my part

For those of you that have bought these in different sizes, which size outer diameter would I have to buy to remove 10mm wedge bolts? Any info is appreciated.

The 13 should work for you. It might just skim the outside of M10 bolts 

10mm bolt info I found online calls for a 12mm hole.  The extra 2mm is for sleeve expansion. 15mm bit has an internal diameter of 12.27 (ish).

Brian Murphey wrote:

10mm bolt info I found online calls for a 12mm hole.  The extra 2mm is for sleeve expansion. 15mm bit has an internal diameter of 12.27 (ish).

I'm not sure where you read that but most 10mm wedge bolts require a 10mm hole.

D13 will be best for 10mm wedge bolts. I have a 10mm threaded rod and it slides right in to a D13: