Spray bottle and soft bristle brush in use in Castle Hill

Derek Thatcher started to climb in Castle Hill some 25 years ago and now they have a protocoll, how to wash boulders to preserve friction on their limestone, video. This method using a spray bottle and a soft bristle brush should not be used on sandstone!

"Washing hand and foot holds has been commonplace in Castle Hill Basin for over 20 years and in recent years with increasing traffic more and more visitors have taken up the process to maximise friction and preserve the rock. Now more climbers are seen carrying garden spray bottles than not and it is so uncommon to visit an ‘unwashed’ climb that it seems offensive when you do. The norm is to wash all the built up rubber and chalk off every boulder when you finish and leave it in perfect condition for the next people (once dried of course). Once you start seeing the benefits of washing any drawbacks seem insignificant, you may even find yourself washing large sport climbs in the hope of improving friction."

Is it true that a polished boulder can have improved friction after a year without climbing?
A year is optimistic! Certainly within 5 to 10 years depending on the aspect, from observation of climbs that have been closed off for various reasons. Lots of small areas of boulders have been closed here and fenced off for native replanting. This is all observational, not science, but I certainly have re-looked at things and have a good memory for texture. I assume it is done by the same weathering processes that give the friction in the first place. I am not a geologist but my understanding is that the micro texture of limestone is formed by water running over the rock and both removing and depositing materials.

One of the largest positives I see here from our campaigning is that the general climber starts to pay way more attention to their impact. Watching when holds start to rubber up and realising they can do something about it.