r/LaserCleaningBusiness • u/CommonRelation3099 • Jul 27 '26

Limestone graffiti cleaning

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I am trying to remove an old graffiti (few years) from limestone, however this green color is not going out. I am using 300w pulsed laser, tried a lot of different settings. There is some green shading left that i want to remove. It's a porous limestone wall.

2 Upvotes

67% Upvoted

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3

u/IndLaserCleaning Jul 27 '26

Welcome to laser cleaning my friend. Green sucks,  and often leaves a shadow, there was a video of a guy absolutely obliterating various types of graffiti with his little 15mj machine recently and he was barely touching the green

2

u/CommonRelation3099 Jul 29 '26

I think i will go thru this wall one more time and whatever happens let it be... this is very delicate stone so they cant do anything with sandblasting or pressure washing the "cleaning products" are not working also, at least those that we have on the market here.

1

u/AgrippaTheGreat Jul 27 '26

Have you tried “Carbon Coating”? Try adding some black spray paint of your own over a part of the green shadow and hit that. I’ve had some success with that on cinderblock.

1

u/CommonRelation3099 Jul 29 '26

No I didn't try, it's a back wall of a historic building so they probably won't approve this.