/ Polished Rock Routes and Repair

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Steve Perry - on 30 Oct 2017
I was wondering if tired routes which are completely polished could be grit blasted and thus repaired. Thinking of places like Horeshoe which are being regenerated with new bolts but on already polished routes. Speaking with a friend of mine who grit blasts for a living, he thinks it could work. Just the other day he grit blasted an entire swimming pool to make the surface rough again for re- coating.
Any one tried this or suggested it?
Oceanrower - on 30 Oct 2017
In reply to Steve Perry:

I like you. You're funny!
Steve Perry - on 30 Oct 2017
In reply to Oceanrower:

It doesn't work then?
Oceanrower - on 30 Oct 2017
In reply to Steve Perry:

I was referring more to the usual UKC resistance to even sticking a bolt in.

If you start grit blasting the rock there will be heart attacks up and down the country.
Steve Perry - on 30 Oct 2017
In reply to Oceanrower:

Ah ok. I don't think it would damage the rock as such but more apply a new rougher coat but I see what you're saying.
Trangia on 30 Oct 2017
In reply to Steve Perry:

Sorry to put a damper on things, but how would you define "completely polished"? Polish sorts out good footwork from bad footwork, but has it ever made a climb unclimbable for even the best?
GrahamD - on 30 Oct 2017
In reply to Steve Perry:

Its a fine line, though, isn't it ? a lot of limestone is naturally shiny. At what point does roughening it up actually become improvement (like a mild form of chipping) ? who arbitrates ? In roughening up rock you are inevitably eroding some of it away which is also a concern.

In reality, a bit of polish rarely makes any significant grade difference in any case but it does need better more positive footwork which is no bad thing.
keith-ratcliffe on 30 Oct 2017
Steve Perry - on 30 Oct 2017
In reply to GrahamD:

I was just remembering some of the posts saying how bad some routes are polished, maybe it doesn't make a difference. I prefer climbing ones that aren't but have done a lot that are.
Steve Perry - on 30 Oct 2017
In reply to Trangia:

Probably not if you have a few grades in hand.
GrahamD - on 30 Oct 2017
In reply to Steve Perry:

A lot of people blame polish rather than their feet
Steve Perry - on 30 Oct 2017
In reply to GrahamD:

So true....me included.
stp - on 30 Oct 2017
In reply to Steve Perry:

I've never heard anyone try this but it sounds like a really interesting idea if workable. Loads of the UK's more popular crags are already trashed and the situation is only going to get worse. I don't actually think Horseshoe is too bad compared to some places like Raven Tor. But how doable would it be bearing in mind it's going to have to be done on an abseil rope? How big/heavy is the equipment needed and how is it powered? Might be possible for boulder problems but would it be feasible on routes?
stp - on 30 Oct 2017
In reply to GrahamD:

The old sticky rubber used to work pretty well on polished rock. It had some kind of resin in it and when you got the boots squeaky clean it stuck to polished holds rather well. The newer rubbers are different though and don't stick nearly as well.
Steve Perry - on 30 Oct 2017
In reply to stp:

Lots of folk do grit blasting offshore with IRATA. The kit is pretty portable.
stp - on 30 Oct 2017
In reply to Steve Perry:

Well if possible I'd give it a go. As above I'm sure some people will whinge from their PC terminals but I suspect of those who actually get out and go climbing the majority would really appreciate it.
johncook - on 30 Oct 2017
In reply to stp:

If you grit blast you take off the polish, which is also an oxydised surface layer which is harder than the matrix of the rock. Once this hard surface has been removed the softer underlayer will erode and polish even quicker. It is especially noticeable on grit where repeated gear placements have removed the oxidised layer and the rock below is very soft and friable. The same is true for limestone.
It may be best to leave the polish alone and teach good foot placement. This will have two effects, it will make it possible to climb on polished rock and it will reduce the rate at which the surface polishes. Most polish is a result of dirty shuffly feet, especially in places like Horseshoe.
(On many older trad routes I tell newer climbers to watch for the two polished footholds. Stand on them carefully and place some good gear, because this is where leaders have stood and faffed as they try to start the hard moves!)
Tim Sparrow on 30 Oct 2017
In reply to Steve Perry:
My first route, back in 1973 was the Arête at Avon. It was horrendously polished even then. Green Flash pumps slid all over the holds. Flared jeans didn't help. Even back then, some had taken a piton hammer to the polished slopey dishes that passed for footholds in an attempt to roughen them up.

So the idea is not all that new really ..
Post edited at 20:03
captain paranoia - on 30 Oct 2017
In reply to johncook:

> If you grit blast you take off the polish, which is also an oxydised surface layer which is harder than the matrix of the rock.

You're talking about gritstone (oxidising, matrix), I think.

Limestone doesn't have a matrix, or form a harder oxidized crust. So I think blasting to remove polish on limestone would be possible without leading to potential erosion damage (like it might with gritstone).

Whether such polish removal is desirable is an entirely different matter. Once polish has formed, and the route becomes harder, I guess you just have to increase the grade from what it was originally.

The last time I tried the easy routes at the Cuttings on Portland, they were a lot harder than when I started in the late 90's, due to the polish.
Steve Perry - on 30 Oct 2017
In reply to captain paranoia:
> Whether such polish removal is desirable is an entirely different matter. Once polish has formed, and the route becomes harder, I guess you just have to increase the grade from what it was originally.

Past generations have polished the rock so is it not up to us to try and return it to how it was for the new generation, or should we not care and they just up their grades to enjoy them?
Post edited at 20:38
johncook - on 30 Oct 2017
In reply to captain paranoia:

Limestone does form a thin hard layer (oxidised), not as thick as grit but still there. Remove it and you can scratch the core with a finger nail. This is why quarried lime polishes much quicker than natural limestone. The natural limestone has had longer to generate a thicker harder surface.
Michael Gordon - on 30 Oct 2017
In reply to captain paranoia:

>
> Whether such polish removal is desirable is an entirely different matter. Once polish has formed, and the route becomes harder, I guess you just have to increase the grade from what it was originally.
>

Unfortunately, increasing the grade does not make the route any more pleasant to climb.
Oceanrower - on 30 Oct 2017
In reply to Steve Perry:
Limestone, in it's quarried state, is normally cut into blocks with a saw, it's that soft.

Ever wondered what all those large blocks are laying around Portland?

That's the quarried stone and they're left there to harden (oxidise).
Post edited at 21:13
Steve Perry - on 30 Oct 2017
In reply to Oceanrower:

I've climbed at Portland once, and if I'm honest I never wondered no.
captain paranoia - on 30 Oct 2017
In reply to Oceanrower:

> Ever wondered what all those large blocks are laying around Portland?

Most of the large blocks laying around on Portland (not in active quarries) are waste, cut out to gain access to the better quality stone below. The Tout quarry, for instance, has high banks built of such waste. Blocks cut in the quarries are sent for dressing. Since harder rock would be harder to dress, why would you leave it for a thin surface hardening to take place?

https://en.m.wikipedia.org/wiki/Portland_stone
Post edited at 21:55
captain paranoia - on 30 Oct 2017
In reply to Michael Gordon:

> Unfortunately, increasing the grade does not make the route any more pleasant to climb.

Agreed.

I have no real opinion on whether removing polish is a good idea or not; I was trying to express one side of the argument. Yours is an equally valid alternative PoV.
skog on 30 Oct 2017
In reply to Oceanrower:

> That's the quarried stone and they're left there to harden (oxidise).

I don't think that's right - the oxidising bit, anyway.

Limestone is mostly calcium carbonate, often with a bit of magnesium carbonate, iron carbonate and other such minerals in it.

It isn't going to oxidise, as it's already oxidised.

I could see that it might possibly harden if left in the rain, with the surface recrystallising as it is partially dissolved then reprecipitated repeatedly. But I don't know how much it really does - it's already normally permeable to water, so I'm not sure exposure to the rain would matter much, it has probably already done plenty of this recrystallising anyway (unless it's very young).

I'm happy to be educated further if someone knows more!

(If you had decided to 'repair' limestone polish, it would probably make more sense to do it using weak acid than by blasting it, so as to leave it with more of a natural texture.)
ashtond6 - on 30 Oct 2017
In reply to Steve Perry:
Jesus Christ you people will debate anything
Post edited at 22:41
Steve Perry - on 30 Oct 2017
In reply to ashtond6:

Is there anything UKC missed?
skog on 30 Oct 2017
In reply to ashtond6:

> Jesus Christ you people will debate anything

Hmm, debatable.

;-)
captain paranoia - on 30 Oct 2017
In reply to ashtond6:

Discuss...
skog on 31 Oct 2017
In reply to skog:

> (If you had decided to 'repair' limestone polish, it would probably make more sense to do it using weak acid than by blasting it, so as to leave it with more of a natural texture.)

I have just realised I said 'weak acid' when I meant 'dilute acid'.

I will proceed to flagellate myself in recompense.
captain paranoia - on 31 Oct 2017
In reply to skog:

Don't. Carbonic acid is a significant cause of limestone erosion. Admittedly, in a geological timescale... As opposed to limescale...
Jon Stewart - on 31 Oct 2017
In reply to johncook:
> It may be best to leave the polish alone and teach good foot placement. This will have two effects, it will make it possible to climb on polished rock and it will reduce the rate at which the surface polishes. Most polish is a result of dirty shuffly feet, especially in places like Horseshoe.

The point about polish is not just that it makes routes a bit harder, it makes them shit. Polished limestone is just shit rock to climb on, whereas good rock, e.g. Lewisian gneiss, grit, bubbly rhyolite, etc, is good because it's got friction. Friction makes climbing subtle as you can use much more marginal holds at any given grade. On shit polished limestone, I have to climb on massive holds, because I get pumped senseless if it's flat or sloping because since there's no friction so I have to squeeze juice out it. Small holds have to be sharp, which is horrible. Climbing on massive holds is boring, atechnical, shit climbing, and slippy rock has no tactile/aesthetic appeal. Climbing on Minus 10 style rock is simply depressing: I can't derive any fun from it at all, it is completely shit.

As for polish resulting from poor footwork, this sounds a bit like sanctimonious nonsense. If this is the case, then why are hard sport climbs, only ever climbed by excellent climbers, polished to death?

If shit polished limestone could be made grippy then I guess I'd be in favour in theory but I don't believe it would work. It would make crap polished limestone even more artificial and crap - there'd no doubt be shitty dustiness everywhere, and the whole thing would seem even more like some totally arbitrary, manufactured challenge - it's not far off chipping or bolt-on resin holds.

Think I'll try to stick to climbing on decent rock, and then moaning about the shitness of UK limestone when I'm forced onto it.
Post edited at 01:17
Michael Gordon - on 31 Oct 2017
In reply to Jon Stewart:

>
> As for polish resulting from poor footwork, this sounds a bit like sanctimonious nonsense. If this is the case, then why are hard sport climbs, only ever climbed by excellent climbers, polished to death?
>

I was thinking that. Was told that in quite a few mainland European countries, the best climbers are basically moving from one wee area to another as each crag becomes trashed through the basic act of climbing on it.
Circus - on 31 Oct 2017
In reply to Jon Stewart:

Just use pof.
GarethSL on 31 Oct 2017
In reply to Oceanrower, Skog & Steve Perry:

The term you kids are looking for is 'case hardening'

http://alliance.la.asu.edu/dorn/CaseHardeningEncyGeomor.pdf

The type and composition of the case is controlled mostly by the internal pore waters of the rock and externally induced elements. With regards to quarrying I believe the intentional case hardening of quarried rock is called seasoning, but this is entirely dependent on what the rock will be used for.

Limestone will case harden like any porous or weathered rock (even granites will case harden). I would argue however that any removal of the hardened surface will have a very limited impact on the rock itself. Remember Horseshoe is well err a quarry that ceased operation in 1969 and has essentially been climbed since (though a quick peruse shows most of the trad routes were done in the 80's). Thus any 'protective' case hardening present on the quarry face has actually happened in a very short period of time. Instantaneously geologically speaking.

As for gritstone*, that case hardens like any porous sandstone will and is certainly not an exclusive feature of grit *cough* sandstone.

*not so relevant to this thread just wanted to throw that in there because this keeps coming up.
Andy Morley - on 31 Oct 2017
In reply to Steve Perry:

> Is there anything UKC missed?

Just that limestone sea-cliffs get something not dissimilar to grit blasting every high tide and they don't seem to have this lack of 'case hardening' or if they do, they don't appear to suffer on it as the surface of tidal cliffs on say the Gower is hard and beautiful to climb on!
skog on 31 Oct 2017
In reply to GarethSL:

Thanks!
pasbury on 31 Oct 2017
In reply to skog:
Is there any evidence of polish reducing naturally? e.g. on crags that have become unfashionable/overgrown.

Thinking only of limestone here e.g. in the Wye valley one side of Wyndcliffe became brambly and unclimbed for quite some time.
Post edited at 09:34
Tricky Dicky - on 31 Oct 2017
In reply to Steve Perry:

What about climbing some of the polished lower grade routes in hob nail boots? Probably how they were originally climbed and the nails may well roughen up the polished areas a bit? You might even be able to find some hawser laid rope and use waist belays for extra authenticity!!

Buildings are often renovated with water jetting etc to clean them up, so if English Heritage got hold of some crags maybe they would try to restore them.......................
jkarran - on 31 Oct 2017
In reply to Steve Perry:

> I was wondering if tired routes which are completely polished could be grit blasted and thus repaired.

What's the point?

Horseshoe has attained that degree of polish in what 15-20 years of popularity (probably a lot less in reality) and it is now essentially stable (the polish, not the crag!) and still enjoyable to climb on, indeed the precision and tension necessitated by the polish makes some of the main wall routes IMO. Blast or etch it and you get grippy holds a millimeter or so smaller, slightly easier routes for a couple of years and growing demand for another blasting/etching in a few years time then another and another...
jk
DubyaJamesDubya - on 31 Oct 2017
In reply to captain paranoia:
> Don't. Carbonic acid is a significant cause of limestone erosion. Admittedly, in a geological timescale... As opposed to limescale...

Can carbonic acid attack a carbonate? I thought the erosion is due to water dissolving it. Of course acid rain is another matter.
Post edited at 13:23
captain paranoia - on 31 Oct 2017
full stottie on 31 Oct 2017
In reply to Steve Perry:
I am fed up with people getting too good, too fast, so I'm planning on increasing the amount of polish on some of my favourite crags.

As there is so much geological expertise around here, could you give me some advice on how to make rocks smoother? I've tried vaseline and beeswax with a rough old buffer, but I'd hope for something more permanent so we can rename many routes in the low friction tradition (Slip Knot, Leg Slip, Soapgut, or even whole areas like Slipstones, The Polish Jungle...)
Dave
Post edited at 14:08
DubyaJamesDubya - on 31 Oct 2017
In reply to captain paranoia:

> Yes. Carbonic acid is an acid. Carbonates dissolve in acids.

> http://www.uh.edu/~jbutler/kunming/carbonates.html


Well I guess it must be so but it seems to defy the logic of acid + base = salt + plus water as the salt formed is expected to be calcium carbonate.
GrahamD - on 31 Oct 2017
In reply to full stottie:

Pof, obviously
paul mitchell - on 31 Oct 2017
In reply to GrahamD:

In Nottingham,parts of the natural crag below the castle have been coated with carbon fibre,moulded to fit.Yuck.
Rog Wilko on 31 Oct 2017
In reply to Trangia:

> Polish sorts out good footwork from bad footwork, but has it ever made a climb unclimbable for even the best?

The best don't ever come up against polish when they're climbing anywhere near their top grade because the hardest routes don't get enough traffic to get polished (or so I imagine). It's the Yorkshire limestone VSs, for example, that become unclimbable for those who could have climbed them before they became polished.
full stottie on 31 Oct 2017
In reply to GrahamD:

> Pof, obviously

Please don't call me names
Rog Wilko on 31 Oct 2017
In reply to Oceanrower:

> Limestone, in it's quarried state, is normally cut into blocks with a saw, it's that soft.

I think your experience must be limited to Jurassic limestones. My house is built of carboniferous limestone and if you don't use a proper (SDS) hammer drill you will just burn out even the best masonry bits in about 20 seconds.

Trangia on 31 Oct 2017
In reply to Rog Wilko:

> The best don't ever come up against polish when they're climbing anywhere near their top grade because the hardest routes don't get enough traffic to get polished

Good point Rog

duchessofmalfi - on 31 Oct 2017
In reply to Trangia:

I recall some recent-ish "improvements" to low level holds in the Avon Gorge (can't recall the crag, near a little layby). Anyway the improvements consisted of lots of small drill dints over the polished footholds. It wasn't pretty or particularly effective, it appeared quite destructive and couldn't really be used effectively on any climb that was worth the effort of climbing without ruining it.
C Witter on 01 Nov 2017
In reply to Rog Wilko:

Maybe "those who could have climbed them before they became polished" are just getting a bit long in the tooth, but don't like to admit it to themselves? ;)
C Witter on 01 Nov 2017
In reply to Steve Perry:

How to deal with the problem of polish is an important question - even if the idea of sand blasting the routes is obviously idiotic.

I do wonder if crags will "recover" over time; but I've also heard that sometimes polish, e.g. on Lower Scout Crag in Langdale, dates back to people climbing routes in hob-nailed boots a century ago. So, I'm not overly hopeful.

In that case, prevention is crucial - and there are some things that can be done. For example, being aware that the guidebook star system leads some routes to be "overclimbed"; and trying to encourage use of a greater range of crags, to avoid people becoming concentrated at a few hotspots. Also, limiting group use of sensitive crags and changing how groups use crags (e.g. not abseiling down established routes; sending kids up in climbing shoes rather than muddy trainers and hiking boots). People are already becoming pretty aware of these sort of issues, though.

Maybe, in time, our shoe rubber will change - "indoor shoes" will be of one type and "outdoor shoes" will be of another, that sticks better to polished rock...

GrahamD - on 01 Nov 2017
In reply to C Witter:

> How to deal with the problem of polish is an important question - even if the idea of sand blasting the routes is obviously idiotic.

I think the first thing we need to do is stop viewing it as 'a problem' and especially 'a problem that needs fixing'. Limestone especially, even in its natural state, can be slippery (think flowstone, for instance) - we just need to deal with it.

Climbing walls probably don't help where the vast majority of footholds are rough as a badgers arse, which don't particularly encourage good positive footwork.
johncook - on 01 Nov 2017
In reply to C Witter:

Try telling the 'group users' in the peak about sensitive routes, clean shoes, not abbing down routes etc. The normal response is "I am a qualified instructor and I know what I am doing and you are only a climber so leave me alone to do what I am going to do!" or word close to that. Eight times in the Peak this summer! And no response from e-mails to their centre for the worst offender, who no doubt is still 'doing what he knows.'
Steve Perry - on 01 Nov 2017
In reply to C Witter:

> How to deal with the problem of polish is an important question - even if the idea of sand blasting the routes is obviously idiotic.

An idea isn't idiotic unless you do it when it's already been proven not to work.

> I do wonder if crags will "recover" over time; but I've also heard that sometimes polish, e.g. on Lower Scout Crag in Langdale, dates back to people climbing routes in hob-nailed boots a century ago. So, I'm not overly hopeful.

How can they recover if people are still climbing on them?

> In that case, prevention is crucial - and there are some things that can be done. For example, being aware that the guidebook star system leads some routes to be "overclimbed"; and trying to encourage use of a greater range of crags, to avoid people becoming concentrated at a few hotspots. Also, limiting group use of sensitive crags and changing how groups use crags (e.g. not abseiling down established routes; sending kids up in climbing shoes rather than muddy trainers and hiking boots). People are already becoming pretty aware of these sort of issues, though.

Who will encourage a greater use of crags and limit use on others and how do you know people are "becoming pretty aware" ?

> Maybe, in time, our shoe rubber will change - "indoor shoes" will be of one type and "outdoor shoes" will be of another, that sticks better to polished rock...

Maybe

Martin Hore - on 01 Nov 2017
In reply to ashtond6:

> Jesus Christ you people will debate anything

I thought it was about time we debated Jesus Christ again on UKC but I think this is the wrong post. Unless he's responsible for polishing the rock.
Martin
Michael Gordon - on 01 Nov 2017
In reply to C Witter:

>
> I do wonder if crags will "recover" over time;
>

Well presumably over millennia there will be gradual weathering which might help. Then again, if/when the next glaciation happens, the routes may become unidentifiable, which could be a worry.
stp - on 01 Nov 2017
In reply to jkarran:

> What's the point?

> Horseshoe has attained that degree of polish in what 15-20 years of popularity (probably a lot less in reality)

More like 30 years though it's probably more popular now than in the eighties.


> and it is now essentially stable (the polish, not the crag!) and still enjoyable to climb on,

I agree it's still fine to climb on. There's a bit of polish here and there but it's nowhere near as polished as some other places. Parts of Raven Tor are really bad. I remember doing Sardine in the eighties thinking it couldn't get any more polished. However it turns out I was completely wrong and it's even more polished and more unpleasant today.

I wouldn't assume Horseshoe to be stable. Give another decade or so and it may well start being unpleasant to climb on.


stp - on 01 Nov 2017
In reply to GrahamD:

> I think the first thing we need to do is stop viewing it as 'a problem' and especially 'a problem that needs fixing'.

It may not be a huge problem now but if we project forward into the future it's seems pretty obvious that sooner or later all our limestone crags are going to be completely trashed. Recognition that this is a growing problem is the first stage of doing something positive about it. Burying our heads in the sand and pretending it's not happening is just not helpful.

Personally I think prevention should be the first line of defence. Perhaps having an ethic where 'working out' on routes is considered unethical could be a start. There's simply no need to train on outdoor routes now the country is blessed with loads of fantastic artificial walls. The sandblasting idea sounds positive but I've no idea about the practicalities of how well it could work.

GrahamD - on 01 Nov 2017
In reply to stp:

> It may not be a huge problem now but if we project forward into the future it's seems pretty obvious that sooner or later all our limestone crags are going to be completely trashed.

Again, this is only true if you equate polish to 'trashed'.

Michael Gordon - on 01 Nov 2017
In reply to stp:

> Perhaps having an ethic where 'working out' on routes is considered unethical could be a start. There's simply no need to train on outdoor routes now the country is blessed with loads of fantastic artificial walls.

Hmmm, if you took that view then surely the minutia of practice required when projecting could be viewed the same way?

Offwidth - on 01 Nov 2017
In reply to johncook:

maybe name and shame here john... have you asked the BMC for help?
johncook - on 01 Nov 2017
In reply to Offwidth:

Both the BMC and the NT were contacted about this. Not by me but another member of the party.
I am not really into naming and shaming but I did tell the group leader that if I saw him doing it again 'I would spread it everywhere'! Haven't been back to Lawrencefield recently for a number of reasons, but I do suspect that the group is still doing exactly the same as they leader said as much at the time!
stp - on 01 Nov 2017
In reply to GrahamD:

Well I've never met a climber who views polish as a good thing.
stp - on 01 Nov 2017
In reply to Michael Gordon:

There's no doubt that projecting takes a heavy toll on the rock. But that's very much part of the game and there's no way round that apart from giving up climbing altogether which of course defeats the purpose.
Michael Gordon - on 02 Nov 2017
In reply to stp:

It's part of the redpointing game. If you restricted it to onsight-style climbing only then I dare say many routes would see many fewer ascents also. Just seems that this is picking and choosing.
stp - on 02 Nov 2017
In reply to Michael Gordon:

If restricted to onsight then many routes wouldn't exist at all.
C Witter on 02 Nov 2017
In reply to Steve Perry:


> Who will encourage a greater use of crags and limit use on others and how do you know people are "becoming pretty aware" ?

Guidebook editors, clubs, instructors, initiatives like the Lakeland Revival. And... based on discussions on here, the advice given to instructors in books/pamphlets, and discussions with individuals... E.g. there was a UKC article/thread some time back about star systems and whether or not they are helpful.

> An idea isn't idiotic unless you do it when it's already been proven not to work.

In that case, perhaps we should try coating the crag with extra-crunchy peanut butter and see if that helps?

C Witter on 02 Nov 2017
In reply to GrahamD:

Aye, you might be on to something there, Graham. If for no other reason than that increasing polish seems inevitable...
Martin Hore - on 02 Nov 2017
In reply to stp:

> It may not be a huge problem now but if we project forward into the future it's seems pretty obvious that sooner or later all our limestone crags are going to be completely trashed.

I'm not sure about this. I think that some limestone crags are naturally recovering regards polish as fewer people climb on them. Last weekend I climbed Catastrophe Grooves at Wildcat and was sure it was less polished than when I last climbed it in 2002. It's a great route, but I had deliberately steered clear of it because of fear of polish. I seconded Cataclysm this time last year and got the same impression - less polished than previously.

Wildcat was in good condition on Saturday when most of the Peak north of Matlock was bathed in drizzle but no-one else was there. I'm inclined to think that falling popularity is helping polished rock recover (but not helping keeping the vegetation at bay of course).

Having said that, on Sunday we were at Stoney and found polish a-plenty. As someone mentioned above, it could be that quarried limestone (even anciently quarried) doesn't polish in quite the same way.

Martin
Steve Perry - on 02 Nov 2017
In reply to C Witter:

> Guidebook editors, clubs, instructors, initiatives like the Lakeland Revival. And... based on discussions on here, the advice given to instructors in books/pamphlets, and discussions with individuals... E.g. there was a UKC article/thread some time back about star systems and whether or not they are helpful.

I find it really sweet that you believe all that, especially that the instructors are out reading books and pamphlets, and not top roping clients up massively polished routes.

summo on 02 Nov 2017
In reply to Steve Perry:

When a few choice crags or quarries become too polished, why not bolt on holds of a matching colour. It won't suit all group users, but may stop groups moving onto the next easiest lines and polishing them. Introductory rocks at Symonds Yat for example.
dunc56 - on 02 Nov 2017
In reply to Steve Perry:

Listen, just wait and after brexit all the polish will have gone.
cb294 - on 02 Nov 2017
In reply to johncook:

How can you oxidise Calcium carbonate?

CB
DubyaJamesDubya - on 02 Nov 2017
In reply to cb294:

> How can you oxidise Calcium carbonate?

> CB

Heating it in a kiln should do the job.
cb294 - on 02 Nov 2017
In reply to DubyaJamesDubya:

Sure, you release CO2 and are left with CaO, which will react with water to form Ca(OH)2 .

But first, this requires energy input, hence the lime kiln, and will not occur spontaneously on the rock surface, and second, none of the atoms involved change their redox state (if my inorganic chemistry knowledge has not completely deserted me), so it is no an oxidation reaction.

CB
Offwidth - on 02 Nov 2017
In reply to cb294:

A lot of oxidation processes on rock forming hard surface layers relate to oxidation of mineral contents (not the matrix).



















cb294 - on 02 Nov 2017
In reply to Offwidth:

What would that be for limestone? I agree that there will be weathering that can make the surface different in its mechanical problem, but I do not see how that is oxidation.

CB
stp - on 02 Nov 2017
In reply to Martin Hore:

> Last weekend I climbed Catastrophe Grooves at Wildcat and was sure it was less polished than when I last climbed it in 2002. It's a great route, but I had deliberately steered clear of it because of fear of polish. I seconded Cataclysm this time last year and got the same impression - less polished than previously.

Well if true that's good news and amazing that such a recovery is that quick. However for the better quality sport climbing crags that seems unlikely to happen because there are so few quality areas to begin with.
johncook - on 02 Nov 2017
In reply to cb294:

Ask cement makers who accelerate the process to produce cement. The carbonate loses CO2 due to action with rain water (cement makers use heat!). It leaves a hard CaO surface. It is a slow process but the resulting oxide is hard and polishes quite quickly. Take a lump of old limestone, scratch the surface. Now break it in pieces and scratch the bits. They are considerably softer. Remove the hard polished surface and the under matrix will wear quickly, especially when trodden on by dozens of gritty feet!
cb294 - on 02 Nov 2017
In reply to johncook:

Tell me the same about the surface of an aluminium bottle, and I would agree: The metal will rapidly be coated by a µm thick but chemically highly inert and scratch resistant Al2O3, i.e. a proper oxide.

The CaO in cement, which is generated by heating limestone in a kiln will react quickly with water to form highly basic Ca(OH)2, which is also extremely water soluble. This will then react with CO2 from the air to form the solid carbonate again, which AFAIK is how concrete sets.

If I remember any chemistry at all his reaction cannot be reversed by an excess of carbonate ions, which would in fact drive more carbonate crystalisation. Weathering of marble or limestone buildings is instead due to other acids such as sulfuorus acid (from SO2 emissions) or lactic and other organic acid (from bacteria, hand sweat, etc...) which even though weak are acidic enough to release the carbonate ions.

If the resulting salts are water soluble you will get erosion/polish. If local conditions (at the micro level) are such that some of these reactions run in the reverse (e.g. if concentrations of these acids vary) you will get redeposition of the carbonate, potentially filling gaps in the matrix and leading to stronger bonding between grains (which is how a snowball hardens, except that the crystals there are dissolved by heat and refreeze, rather than chemically).

I assume that such dissolution/reprecipitation processes drive the formation of hardened surface layers on limestone. In any case, splitting a rock and scratching the newly exposed surface is not particularly informative, as the surface will be shattered at the microscopic level, with loads of terminating cracks that in the end did not contribute to the macroscopic break, but will weaken the surface.

In contrast to the claims further up in the thread I was initially responding to none of this involves any oxidation, unlike, say, chucking a chunk of metallic calcium into water or burning it in air.

I am sure, though, that one of the resident geologists soon comes along to put me in my place!

CB


oldie - on 02 Nov 2017
In reply to cb294:

> ..... reaction cannot be reversed by an excess of carbonate ions, which would in fact drive more carbonate crystalisation. Weathering of marble or limestone buildings is instead due to other acids such as sulfuorus acid (from SO2 emissions) or lactic and other organic acid (from bacteria, hand sweat, etc...) which even though weak are acidic enough to release the carbonate ions. <

I think the reaction of carbonic acid with calcium carbonate
would produce carbon dioxide which would escape and so the reaction (limestone erosion) would continue.
I may be completely wrong, trying to remember school chemistry!
blurty - on 02 Nov 2017
cb294 - on 02 Nov 2017
In reply to oldie:

Guess you have this mixed up.

Calcium carbonate is the salt of carbonic acid. Adding more carbonic acid, which is in equilibrium with CO2 and water, would if anything drive more of the salt to precipitation (as there are more of the constituent ions present in the solution).

However, any other, stronger acid will release carbonic acid, which would then fall apart into CO2 and water until the equilibrium is reached. Any CO2 escaping into the air would then drive the equilibrium more in that direction, which is what you may have had in mind.

CB

Si_G - on 02 Nov 2017
In reply to blurty:

When I was up Beinn Eighe they were crosshatching the quartzite path with an angle grinder because it was a slippery death trap.

I hope nobody “restores” footholds like this :D
oldie - on 03 Nov 2017
In reply to cb294:

> Calcium carbonate is the salt of carbonic acid. Adding more carbonic acid, which is in equilibrium with CO2 and water, would if anything drive more of the salt to precipitation (as there are more of the constituent ions present in the solution).

Thanks. My explanation is obviously wrong.
However just Googled and RGS and RSC imply CO2 erodes limestone

Geological Society website
"Solution - removal of rock in solution by acidic rainwater. In particular, limestone is weathered by rainwater containing dissolved CO2, (this process is sometimes called carbonation)."
Also Royal Society of Chemistry site
"Topic. The chemical attack on limestone by rain that is naturally acidic (containing dissolved carbon dioxide) and ‘acid rain’ (rain that is more acidic because of dissolved pollutants such as sulfur dioxide and nitrogen oxides).
"Students blow through a straw into water containing a little Universal Indicator and note that the water becomes slightly acidic because carbon dioxide from their breath dissolves in it. They then add limestone chippings to the water and note that the solution gradually becomes neutral as the calcium carbonate in the chippings reacts with the acid."
cb294 - on 03 Nov 2017
In reply to oldie:

The change in pH in the breathing experiment is due to buffering between CO3-- and HCO3- (which is more my field, biology rather than geology...). This could possibly also be a mechanism for carbonic acid reacting with limestone, but again the equilibrium of the reaction should go the other way.

CB
summo on 03 Nov 2017
In reply to Si_G:

> When I was up Beinn Eighe they were crosshatching the quartzite path with an angle grinder because it was a slippery death trap.
> I hope nobody “restores” footholds like this :D

Is it acceptable for thousand of foot to wear a rock smooth, kill trees, cause ground erosion and to drill bolt holes, but not to say chisel new holds on previously polished rock?

I would say in a quarry on a case by case basis why not?
oldie - on 03 Nov 2017
In reply to cb294:
> The change in pH in the breathing experiment is due to buffering between CO3-- and HCO3- (which is more my field, biology rather than geology...). This could possibly also be a mechanism for carbonic acid reacting with limestone, but again the equilibrium of the reaction should go the other way. <

How about CO2 and water, ie “carbonic acid” H2CO3, react with calcium carbonate to give calcium bicarbonate which is soluble and so washes away and the reaction proceeds in this direction?
Could be how stalactites form if this is reversed as water drips from cave roofs.

H2CO3+ CaCO3 gives Ca(HCO3)2











Si_G - on 03 Nov 2017
In reply to summo:

> Is it acceptable for thousand of foot to wear a rock smooth, kill trees, cause ground erosion and to drill bolt holes, but not to say chisel new holds on previously polished rock?

> I would say in a quarry on a case by case basis why not?

If you’re going to do that, then you’re effectively chipping a rock climbing wall, only without the flexibility of routes.
It’s not really in the ethic, is it?
summo on 03 Nov 2017
In reply to Si_G:

> If you’re going to do that, then you’re effectively chipping a rock climbing wall, only without the flexibility of routes.
> It’s not really in the ethic, is it?

But it's ethical to climb a face to the point where every feature is worn smooth, or every bit of soil is removed?

I'm talking about mainly quarries, not making nice new crisp edges on cenotaph corner.
charliesdad - on 03 Nov 2017
In reply to GrahamD:

For those who do see it as a problem, one solution is to stop climbing these polished horrors, and come to Cumbria; we have thousands of unpolished routes which are disappearing under a carpet of bracken and moss, because few people seem motivated to climb them. Please, bring your poor footwork to Cumbria and save a lonely crag!
GrahamD - on 06 Nov 2017
In reply to charliesdad:

I'll be interested in seeing your ticklist of venues for next time I'm there !
Toerag - on 06 Nov 2017
In reply to Steve Perry:

Personally I think there's two sorts of polish mechanisms:-
1) raised bits of rough texture being worn off / dissolved
2) depressed bits of rough texture being filled up with hand slime / chalk
Both will be in operation at the same time in the majority of cases. The question is, can mechanism 2 be undone? Obviously mechanism (1) can't be, but removing the clag in the texture should be possible.
oldie - on 09 Nov 2017
In reply to Toerag:

Possibly if the filling was removed it would leave the raised bits more liable to break off, so leaving type 1) anyway!
GrahamD - on 09 Nov 2017
In reply to oldie:

Who's to say what is 'natural' filling rather than man made degradation ?
oldie - on 09 Nov 2017
In reply to GrahamD:

Possibly irrelevant whether natural or not as the result (whatever that actually is) of deliberately removing it might be the same.
oldie - on 09 Nov 2017
In reply to GrahamD:
Possibly natural or not is irrelevant as the effects of cleaning (whatever they actually are) might be the same.
Incidentally would not a stiffish brush undo clogging in mechanism 2? Must patent it.

PS Apologies for duplicate reply as my first post didn't appear on my PC earlier.
Post edited at 13:30
GrahamD - on 09 Nov 2017
In reply to oldie:

> Possibly irrelevant whether natural or not as the result (whatever that actually is) of deliberately removing it might be the same.

Possibly - but in one case you have restored the route and in the other you have enhanced it.

The point is probably more pertinent when talking about removing polish - just how rough was the rock initially ? there has to be a temptation to actually make holds rougher than they were for their first ascent. As far as I know first ascensionists don't measure the reflective index of the rock they are climbing before starting.

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