What is best for removing spray paint underground from slate?

[Space Doubt Caver]

Hey UKC folks,
I went on a good trip yesterday to an open slate mine near Llangollen, (Mentioning no location name).

We entered the mine to go for a good explore, i was shocked to find inside the mine is lots of graffiti and vandalism, it was quite a shock because this mine is a fantastic walk in/walk out.

I want to go back and clean the spray-paint from the mine, i'm looking for some advice on what is best to remove spray paint from inside the mine?

The mine itself is slate, not sure if that makes any difference to how it's cleaned.

Thanks in advance

 

[pwhole]

We managed to clean off spraypaint in Suicide Cave in Castleton with just water sprayers and wire brushes, and the rock there is like fossil porridge, so very rough-textured. A few bits were just too small and ingrained to get out, but we got most off - I'm sure slate would be easier. Sadly it's been re-done again recently, much worse this time, and I can't face it again - the last session was three hours solid scrubbing. Trying to prevent the paint-infused water from entering the water-table via the rubble floor was a step too far.

 

[georgenorth]

Hey UKC folks,
I went on a good trip yesterday to an open slate mine near Llangollen, (Mentioning no location name).

We entered the mine to go for a good explore, i was shocked to find inside the mine is lots of graffiti and vandalism, it was quite a shock because this mine is a fantastic walk in/walk out.

I want to go back and clean the spray-paint from the mine, i'm looking for some advice on what is best to remove spray paint from inside the mine?

The mine itself is slate, not sure if that makes any difference to how it's cleaned.

Thanks in advance

Targ graffiti remover works ok I believe. Unfortunately all chemical removers are pretty expensive (approx. £90 for 5l).

Alternatively, a wire wheel on a battery grinder might be a faster alternative to the wire brush approach if you’ve got one.

 

[Space Doubt Caver]

Targ graffiti remover works ok I believe. Unfortunately all chemical removers are pretty expensive (approx. £90 for 5l).

Alternatively, a wire wheel on a battery grinder might be a faster alternative to the wire brush approach if you’ve got one.

a brush grinder could be affective, i don't like the idea of using chemicals because sometimes the biproduct of the reaction can be toxic in enclosed spaces, but going up with a grinder some batteries and a wire brush sounds great

 

[Cantclimbtom]

Not tried it but for graffiti removal (instead cleaning small patches of rust), but if you have a battery drill but not a grinder, there are some wire brush wheels for drills that work OK. Less horsepower than a grinder though.

 

[RobinGriffiths]

Was it yellow graffiti? Think I visited that over Easter. Shocking amount of graffiti.

 

[Space Doubt Caver]

Was it yellow graffiti? Think I visited that over Easter. Shocking amount of graffiti.

yes it was and some white graffiti too

 

[Pete K]

The walls probably have a fine coating of dust/mud from the drilling, meaning the paint will not necessarily be well adhered to the rock. A simple nylon brush and water should shift most of it before resorting to the wire brush or grinder wheel stuff suggested above. The slate will be worn down by heavy abrasives and probably show a visible mark forever. It's not the hardest of rocks!

 

[ChrisB]

I've removed spray paint from (non-rock) surfaces using DOT4 brake fluid. An internet search suggests that it's officially designated as hazardous but that in practice it's biodegradable and low toxicity. I don't know how it works on rock (but it would be easy to test in a protected environment) and I'd be happy to hear from anyone who knows the full story about how hazardous it is.

 

[mikem]

It very much depends what the paint is, after all white board marker will remove permanent...

 

[Steve Clark]

If you're using a wire wheel on a drill or a grinder, please wear some safety glasses. We had a horrible injury / safety alert at work where a tiny brass wire shot deep inside someone's eye. It's not obvious like grinding sparks and it only takes one.

 

[AR]

Contact adhesive is pretty good at shifting spray paint off rock, smear some over it then roll it around like a large bogey and it picks up a lot of the paint thanks to the naptha in it. However, you do need a chemical filter mask for doing this underground (not expensive, £20-£25 IIRC). You may need to swab the remainder off with another solvent, I used xylene in Cumberland Cavern but that was partily because I already had a can of the stuff. Alternatives you could try would be white spirit, meths, or acetone

 

[Flotsam]

Subject to testing on a small area, Sodium Hydroxide dissolved in water and thickened with wallpaper paste. I've used it for stripping boats. As I remember I used about 200g hydroxide in 10l of water. Use gloves, protective suits and eye protection!

 

[Space Doubt Caver]

Contact adhesive is pretty good at shifting spray paint off rock, smear some over it then roll it around like a large bogey and it picks up a lot of the paint thanks to the naptha in it. However, you do need a chemical filter mask for doing this underground (not expensive, £20-£25 IIRC). You may need to swab the remainder off with another solvent, I used xylene in Cumberland Cavern but that was partily because I already had a can of the stuff. Alternatives you could try would be white spirit, meths, or acetone

Acetone could be good, also white spirit could be good, i've used those for other things before, could be a great less invasive method i will try that, i'll take a short bristled brush see how it goes

 

[Maj]

Some years ago we tried various methods to remove some spray paint on a limestone rockface on the surface. I can't recall everything we tried but it included:- Graffiti Remover, White Spirit, Meths, Wire brush. Nothing really worked that well. Perhaps not helped by the clean washed, hardly weathered surface. In the end we resorted to spray painting over with a grey paint with a fairly close colour match to the limestone, feathered in at the edges of the area. This worked well and now some years later I can't find where it was despite knowing the location within approx 30 metres.

 

[pwhole]

Now there's a new market! Colour charts for each rock type. The Bee Low tin wouldn't get much use in Castleton though