[Banana finger]

This is probably a daft question but what would the consensus be on de-polishing routes?

This is assuming there is some method of de-polishing a hold with something abrasive or chemical perhaps?

Obviously this will drop grades but will massively increase quality. I'd be happy to take that hit.

For example if the start of sardine was sorted out...might drop loads of grades by a plus but would make the climbing infinitely better.

Obviously I'm not going to do it, but how would people feel? Is there some strong argument against? Like historical value or something...I guess the routes were historically not polished would be a contrapoint to that?

for clarity i mean polish as in 'a smooth veneer', not the nationality. This would read very differently if i implied the latter 

[HaeMeS]

I doubt some sort of chemical removal process will work since the chemical composition of rock varies and the process will probably remove the micro-texture of the rock which is the last thing you’d want.

Coating polished holds does work though. It’s been tried on a couple of routes in one of the climbing areas we’re involved with. Holds were coated in epoxy and sand with the same colour as the rock. It’s sure works but the job was criticized by a very vocal group of old farts even though it is not that visually noticeable for the majority of climbers. It’s a controversial subject... 

[Andy F]

Would spraying a dilute solution of hydrochloric acid, say a 1 molar solution, work? I'd try a small area first, then jetwash the crag. Maybe the BMC could help out? Drones for the higher up sections of routes?

[SA Chris]

shot or sand blasting has been suggested in the past too.

[Ru]

Would spraying a dilute solution of hydrochloric acid, say a 1 molar solution, work? I'd try a small area first, then jetwash the crag. Maybe the BMC could help out? Drones for the higher up sections of routes?

I believe something similar was tried a number of years back on a foothold on Kudos wall. If I remember rightly there was a small but noticeable improvement that polished out again with a few months.

[duncan]

Tom Proctor tried hydrochloric acid on holds at Stoney in the 1970s, polished to a high gloss even then. I don't think the experiments came to anything.

[Ged]

Would it really improve the quality that much? I don't mind a bit of polished lime. Makes you climb well.

[tomtom]

Isn’t all lime polished? 😂

[Andy F]

Tom Proctor tried hydrochloric acid on holds at Stoney in the 1970s, polished to a high gloss even then. I don't think the experiments came to anything.

What concentration was used? Would a higher concentration have a more noticeable and longer lasting effect?

[moose]

Isn’t all lime polished? 😂

I've seen glossy rock on barely ever climbed 9a's... I think some polish is just inherent to the rock (drainage / historical water flow?).  Whatever, I just tell myself that polished footholds are nature's / God's way of telling me I need more core strength.

[SA Chris]

OT, but there are Quartzite crags in the Magaliesberg where ledges have apparently been polished by the fur of Dassies (Rock Hyrax) going back and forth along them for thousands of years.

[andy popp]

Where's King Canute when we need him?

[SamT]

Tom Proctor tried hydrochloric acid on holds at Stoney in the 1970s, polished to a high gloss even then. I don't think the experiments came to anything.

What concentration was used? Would a higher concentration have a more noticeable and longer lasting effect?

The look on someone's face as the crucial crux foothold slowly dissolved way to nothing 

[SA Chris]

followed shortly by the end of their climbing shoe and their toes.

[Andy F]

Tom Proctor tried hydrochloric acid on holds at Stoney in the 1970s, polished to a high gloss even then. I don't think the experiments came to anything.

What concentration was used? Would a higher concentration have a more noticeable and longer lasting effect?

The look on someone's face as the crucial crux foothold slowly dissolved way to nothing 

Doesn't that happen on most Peak Lime anyway 

[battery]

shot or sand blasting has been suggested in the past too.

Wasn't Dumby sandblasted by the council to remove graffiti?

[Bonjoy]

It's incredible how fast some limestone acquires polish. I've had projects that have polished footholds within a dozen or so attempts. Given this and the fact that a chemical solution would erode the hold, the idea doesn't sound sustainable.
Textured resin coating would be more sustainable but is more artificial and would potentially change the look and difficulty of a climb.
The above notwithstanding, I think there might be a case for considering the idea if something becomes literally unclimbable.

[SA Chris]

Yes, but only the newer stuff, not that of historical value. I think they were careful that it didn't affect any of the problems and actually create any friction on them.

https://www.bbc.co.uk/news/uk-scotland-glasgow-west-21806641

I go sometimes wonder if it would be possible remove the glaze caused by pof from some of the footholds in font. Worse than any natural polish.

[tomtom]

It's incredible how fast some limestone acquires polish. I've had projects that have polished footholds within a dozen or so attempts. Given this and the fact that a chemical solution would erode the hold, the idea doesn't sound sustainable.
Textured resin coating would be more sustainable but is more artificial and would potentially change the look and difficulty of a climb.
The above notwithstanding, I think there might be a case for considering the idea if something becomes literally unclimbable.

Not all limestone is created equal

There are different levels of impurity - and for climbing any grainsize differences will have an effect.

Eg. Limestone formed from a deep ocean setting will likely have very fine muds in its mix, whereas those formed in delta’s or closer to the shore are more likely to have sand/fine sand within them as well. My memory is super hazy on this, but Iirc the Mag lime belts east of the peak are from a more coastal setting (lots of reef deposits) and unsurprisingly the mag lime of anston etc.. often retains some friction despite being polished.

Table 3 in this PDF has some interesting data on the ‘purity’ of UK lime areas and perhaps unsurprisingly Malham is super pure - which may help explain its slickness.

http://nora.nerc.ac.uk/id/eprint/15887/1/Reconnaissance_assessment_of_high-purity_limestone_plus_references.pdf

http://nora.nerc.ac.uk/id/eprint/15887/1/Reconnaissance_assessment_of_high-purity_limestone_plus_references.pdf

Upshot is - if it’s really pure/fine grain then stripping back the top layer with acid is just going to reveal more of the same super hard slick stuff. Like taking a layer off a block of glass…

One alternative might be to machine texture in the surface (like the grip patterns on Beastmaker chrome domes) but ethically that’s obviously a non starter.

Grit/sandstone is more complex as you have to consider how well glued together it is (basically how well it is naturally cemented together) and the patina or hard weathered surface found on many natural outcrops. Often once the patina is breached below wears/weathers much more quickly. I’d imagine that some polished grit could be brought back with a thin layer of glue and sand sprinkled on top (making sandpaper effectively) but expect that would last not very long.

Sorry if any of this is wrong or teaching people to suck eggs etc…

[cheque]

Grit/sandstone is more complex as you have to consider how well glued together it is (basically how well it is naturally cemented together) and the patina or hard weathered surface found on many natural outcrops. Often once the patina is breached below wears/weathers much more quickly.

Polished grit is fascinating stuff. When you look at really polished bits like Castle Crack at Stanage Popular it’s like the grains that have been worn away (principally by nailed boots I believe) and all that’s left is the “glue” that holds them together. When you see old photos from when they wore nails (and that cool old colour video of Stanage that I can never seem to find) there are big sandy patches all over the place that are now these glassy smooth grainless bits. It seems some sort of oxidisation process creates them over time.

[SA Chris]

Same at Almscliff.

Amazing to think the hobnailers who created the big sandy patches never thought they were doing much harm at the time. Guess outcrops were still thought of "just training" and expendable.

[DAVETHOMAS90]

It's something that's always been debated - say for the worst bits at Stoney - but as BJ says, routes will polish up again.

I like the idea of using drones, but preferably to spray water on holds if someone looks like they'll beat you to the red-point.

It's an important question though, given the far greater erosion. On limestone, you tend to reach a max level of polish, which in a way, reduces further damage.

Unfortunately, on grit, yes, once the top layer has been lost, further erosion will happen far more quickly. The bouldering at Cratcliffe cliff top, is the best example I can think of. It's a great shame, given how good the slabs were there, say 30 years ago.

Damage that extensive would be difficult to recover, but I think there are good examples of where something preventative, could be a great idea.

I think a simple clear resin compound (something like that) would be good to use on certain holds on grit, to help slow down further erosion. The hold you go through to on Jerry's trav at Stanage Plantation would seem like a prime candidate, as it's also a foothold on 'Rose.

Maybe we could have a thread to discuss more specific examples.
Dynamite would probably have a longer lasting effect on routes at the Tor.

[SA Chris]

Dynamite would probably have a longer lasting effect on routes at the Tor.

Couldn't make it any worse

[tomtom]

Much of the grit/sandstone stuff is covered in other thread Dave - generally under crag erosion etc..

Dynamite would probably have a longer lasting effect on routes at the Tor.

Couldn't make it any worse

Whilst nuking it from orbit (Aliens) would also work, how about excavating? The floor of Ben’s is an old lava flow - so depending how thick it is - you could dig down a few M and add a volcanic start turning all the cave/lip problems into routes. Recon you could go down about 5-8 m before you’d need to pump it out…

[mrjonathanr]

The floor of Ben’s is an old lava flow

Is it not limestone then? I assumed it was flowstone?