[petejh]

The Traversi blow-torching thread got me wondering about tools for drying damp holds which don't damage the rock like blow-torches do. Before anyone says it - I know, a beer towel and chalk. But is there a place for a cordless version of the heat gun I use for sealing rope tags (basically an industrial strength hair-dryer)?
Someone correct me if I'm wrong but the issue with blowtorches is the extreme heating up in a very concentrated zone, plus the flame on the rock?

A hot air gun on the other hand wouldn't be destructive because the hot air isn't as concentrated and it isn't putting a flame on the rock.
Cordless heat gun here: http://www.hilltop-products.co.uk/heat-guns/cordless-gas-heat-guns/steinel-bhg-360-cordless-heat-gun.html#.UNhRI3dLd8E  but it's well expensive.
This looks good though: http://www.hilltop-products.co.uk/heat-guns/cordless-gas-heat-guns/gas-hot-air-gun.html#.UNhSYHdLd8E

Could be well handy for drying damp holds, or does anyone think this sort of air-heating would still be destructive?

Perhaps there's a niche in the market for a lower-temp air gun if the temperatures involved with these hot air guns are too high?

(don't flame me)

[andyd]

Thin end of the wedge...

[lagerstarfish]

I often wondered about using/modifying disposable nappies (or the magic crystals inside them) for drying holds. Silica gel might work fine, but it will also absord moisture from the air. My initial thoughts are that nappy gunk is designed to absorb on contact, which is what is needed. That stuff is amazing - probably very poisonous for wildlife though

instead of heating air, and therefore heating the rock, it is possible to produce dry air that isn't hot - air conditioning - however this uses a fuckload of energy, which means a big energy source

actually, just blowing unheated air will work as long as relative humidity is below 100% , will be slower than heated and therfore lower relative humidity air - folding Japanese style fans could be good for warming up the wrists whilst drying holds

[petejh]

... - folding Japanese style fans could be good for warming up the wrists whilst drying holds

Hmm... how so?

[slackline]

[duncan]

Talking of Japanese fans...the Mitsubishi Jet Towel (and remarkably similar Dyson Airblade) demonstrate you don't need heat to dry things if the air moves fast enough. 

Would a leaf blower or bottle of compressed air do the job? 

[moose]

When I'm desperate to tick a damp project, I lease Brian Blessed to bellow at the holds.  His awesome lung-power leaves even the dankest cracks drier than a good martini.  Care has to be taken with loose or conglomerate rocks though; I once deployed him at Churnet and his cry of "GORDONS ALIVE!" propelled a bunter stone to Alton Towers where it derailed a roller coaster.

[andy_e]

The best way to dry a hold is to let the breeze do its job. Any heat applied (rapidly and/or above ambient temperature) to pore fluids will cause expansion, increasing pore pressure and reducing effective stress between rock grains and therefore forcing grains apart where there is no confining pressure. This leads to grain loss and erosion. If you could apply a cool air to the rock like a localised strong breeze, it would dry the holds efficiently and safely.

[slackline]

What andi_e said (he's a geologist).

[buddah of brodie]

what about a co2 fire extnguisher?

[Johnny Brown]

That would be great for cooling holds down, but not drying them out. I suspect such localised cooling could also cause similar problems to blowtorching.

If you could apply a cool air to the rock like a localised strong breeze, it would dry the holds efficiently and safely

I've always assumed this is the principle behind thwacking the holds with a rag. Certainly seems to work.

[clgladiator]

I think kayakers use meths (slosh a bit on then light it and burn it off) to dry their boats before patching, obviously this doesn't damage the boat, I've always wondered if it would work on rock? I'm not suggesting anyone goes and does this at stoney but there's plenty of crappy grit around it could be tried out on.

[tomtom]

Christ, what kind of crazy "I WANT IT NOW" world do we live in... just wait until its dry!

The rock will still be there another day (as long as we treat it right!)

[andy_e]

meths (slosh a bit on then light it and burn it off)

Any heat applied (rapidly ...) ... leads to grain loss and erosion.

I've always assumed this is the principle behind thwacking the holds with a rag. Certainly seems to work.

I had assumed this too. Its efficiency depends upon the whacking rag in question, the better-tasting the beer from the brewery supplying it, the better it will work. The location of the brewery relative to the boulders is also important. Studies show that an Abbeydale brewery towel will not function well at Brimham but works very well at Burbage, and likewise a Copper Dragon towel works very well at Earl but is bob at Cratcliffe.

[Jaspersharpe]

Whereas using a Carling one will work the opposite way and cover the holds in a horrible tasteless clag.

[Dave Flanagan]

I think kayakers use meths (slosh a bit on then light it and burn it off) to dry their boats before patching, obviously this doesn't damage the boat, I've always wondered if it would work on rock? I'm not suggesting anyone goes and does this at stoney but there's plenty of crappy grit around it could be tried out on.

I have to admit I did try this once on a chossy bit of coastal limestone. It didn't work as I couldn't get the meths to light.

[SA Chris]

Whereas using a Carling one will work the opposite way and cover the holds in a horrible tasteless clag.

But a Heineken one refreshes the parts of holds other beer towels can't reach.

[andy_e]

If Carlsberg made beer towels they'd be too bubbly and shit at drying.

[tomtom]

Camra beer towels make the rock grow a beard...

[lagerstarfish]

Camra beer towels make the rock grow a beard...

and leave ticker marks on the rock ?

[JohnM]

Just chip the wet rock off.  The rock underneath will usually be dry.

[lagerstarfish]

It didn't work as I couldn't get the meths to light.

you need a blowtorch to get the meths lit - you won't be using the torch to dry the hold, so you should be OK if you get a decent lawyer

[tomtom]

It didn't work as I couldn't get the meths to light.

you need a blowtorch to get the meths lit - you won't be using the torch to dry the hold, so you should be OK if you get a decent lawyer

Would it be acceptable to use burning lawyers to dry the holds?

[Dave Flanagan]

I'm going to try this next time

[andy_e]

Yeah, but don't let the arrow go right over the crag as it probably wouldn't work.