Resin Anchor cut off - Sell Gill

[georgenorth]

A diamond core drill should cut through the tangs without too much bother.

 

[Bob Mehew]

Putting a 12 mm anchor in a 21 mm hole should probably invite caution... plus you may need to re-drill the hole after diamond core drilling to get an adequate 'roughness' so might end up being 22 mm. That said the Fischer EM resin is rated for diamond-drilled holes. Would be a very bad idea, I suspect, with the Fischer V Plus resin.

Simon Wilson did do some work on this which suggests otherwise, see Test 1c at https://cncc.org.uk/equipment/ic-anchor/docs/IC-Anchor-Testing.pdf going from a 12 to 18mm hole. But I agree that the hole sides would have to be roughened up to facilitate the resin to rock mechanical bond which is a significant component of the strength of the anchor system. Especially if the anchor eventually becomes loose!

 

[georgenorth]

The HowNot2 video (very helpfully) links to an alternative supplier (AliExpress) so you can get them direct, cheaper, and with a greater range of sizes. (I assumed this is what IanP was asking about). The wall thickness is 1.25mm so a 19mmOD should go over a 16mm DMM. For the small cost its worth a go in my opinion.

I love to go to local suppliers with a good reputation, but I think we should be considering other options too. Having a small hole diameter is important for hole re-use. And the equipment looks lightweight and compact, which is an advantage. Possibly not as robust though.

https://www.youtube.com/watch?v=Nf0W34PqTXc

Free Shipping! New Stone drill bit, Shank Shape: Morse Cone, Total length:123mm, Customizable. - AliExpress 1420

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Glass drilling machine Water Chuck (for connecting drill bit with water pipe). Adapter for 1/2

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

I’ve not seen those before. It looks like a situation in which their cheap Chinese crappiness might be advantageous!

 

[Ian P]

@Ian P you are spot on but as Chris B says it it designed to cut re-bar to so it might work...

Every day is a school day.
Having drilled “normal” holes

I’ve not seen those before. It looks like a situation in which their cheap Chinese crappiness might be advantageous!

I think these are worth a go as a first port of call.
With your knowledge, what are your thoughts?

 

[georgenorth]

Every day is a school day.
Having drilled “normal” holes

I think these are worth a go as a first port of call.
With your knowledge, what are your thoughts?

Definitely worth a go with plenty of water to keep the diamonds cool. I’m not sure how they’ll cope with cutting through SS though. I wouldn’t expect to get many holes out of one regardless, but I assume they’re cheap enough. It looks like the shank on them is morse taper, so you’d need to adapt the water swivel which has a 1/2” female thread on the ones I’ve seen.

The problem with the TC insert thing that Sam linked to will be the SS work hardening. It needs constant feed pressure to keep the SS cutting - to point out the obvious, hand drilling in a cave is very different to a TC insert tool mounted on a lathe!

 

[Ian P]

Definitely worth a go with plenty of water to keep the diamonds cool. I’m not sure how they’ll cope with cutting through SS though. I wouldn’t expect to get many holes out of one regardless, but I assume they’re cheap enough. It looks like the shank on them is morse taper, so you’d need to adapt the water swivel which has a 1/2” female thread on the ones I’ve seen.

The problem with the TC insert thing that Sam linked to will be the SS work hardening. It needs constant feed pressure to keep the SS cutting - to point out the obvious, hand drilling in a cave is very different to a TC insert tool mounted on a lathe!

Thanks George.
Plenty of water won’t be a problem .

Cheers
Ian

 

[andrewmcleod]

Simon Wilson did do some work on this which suggests otherwise, see Test 1c at https://cncc.org.uk/equipment/ic-anchor/docs/IC-Anchor-Testing.pdf going from a 12 to 18mm hole. But I agree that the hole sides would have to be roughened up to facilitate the resin to rock mechanical bond which is a significant component of the strength of the anchor system. Especially if the anchor eventually becomes loose!

And those tests, described here:

Testing - IC Resin Anchor

Describes the testing of the IC resin fixed anchor for caving.

web.archive.org

were done with the FIS V resin, but despite testing indicating it was OK, subsequent issues with shrinkage, as partly described here:

Resins - IC Resin Anchor

Describes the resins used for resin fixed anchor for caving and climbing.

web.archive.org

meant that some early anchors suffered from shrinkage when (I believe) placed in oversized holes, and led to a change in the CNCC to the Fischer EM resin. At least some other regions continue to use FIS V but don't install in oversized holes (and/or use BP anchors).

 

[Cantclimbtom]

Silly question please... while the anchor has been chopped, is it a real pain in the rear to traverse there on the wet route, or is the anchor missing more a minor inconvenience

 

[Ian P]

Silly question please... while the anchor has been chopped, is it a real pain in the rear to traverse there on the wet route, or is the anchor missing more a minor inconvenience

Hi Tom

No issues at all in traversing with this anchor missing. The rope just “cuts across” the traverse, rather than following the curve of the wall.