[Moderator David@stives]

Question for you.

What do i need to get graffitti off a rendered wall coated with stone chippings, I tried pressure washing but it was just blowing the stones out of the render.

Thanks

Dave

[Chris Cottrell]

Fwiw Dave  think its a repaint job by the sound of it

[Moderator David@stives]

Its not painted just render and chippings

[Chris Cottrell]

Oh dear!!

[jeff1]

You can use a system called softblast, its a method of sand blasting but using a softer sand its not a Job you can do your self unless anyone has any other ideas.
Google softblast for more info

[jeff1]

This might give you some tips

www.ci.minneapolis.mn.us/police/crime-prevention/docs/graffitiremoveltechniques.pdf

[Captain Scarlet]

you will need pressurised steam i pressume. The heat will allow a lower pressure to be used, Luke

[Glyn H]

Hi Dave
Just seen this message.
Render is very difficult to remove from due to the chippings becoming dislodged as you have already found out.
I think it will require slow and laborious gentle hand scrubbing.

Is it aerosol, brush applied or felt tip?

[Moderator David@stives]

Aerosol 

[Moderator David@stives]

Do you thing Caustic soda will do it ?

[jeff1]

www.softblast.co.uk/

[Glyn H]

We have these "softblast" units in stock they are a hopper unit that links to a pressure washer which  deposits a grade of bicarbonite of soda into the high pressure water stream.
Unfortunatly I dont believe it would be suitable for your problem as the stone chips will be dislodged.

How big is the graffiti area and what colour aerosol ?

[Glyn H]

As a cheap trial, I would suggest you buy some nitromors from a hardware shop apply it with a paint brush ( type with an unpainted handle) leave it on for at least 30 minites - DOnot poke it about or become impatient and keep dabbing it
After 30 minites use the brush to move the chemical about, you will find much of the paint will have lifted from the surface and become mixed with the chemical.
Remove the gunk with an old absorbant cloth - DONT use Water yet!
reapply the chemical and go through the same process, you are using a poltice to draw the pigment out of the wall.
After second time wash and scrub with hot water - dont use cold.

You may be left with a shadow - let me know how you get on.

Wear rubber  gloves at all times - methylene chloride ( what nitromors is made of ) burns.

[Moderator David@stives]

Glyn
Thanks Much appreciated.

the area is about a foot square it is an outline of a face in black with a red seperate line.

I will try it over the weekend and let you know the outcome

[Blue Sky 2]

Try www.GraffitiHotline.co.uk

John.

[jmb]

dave before you do remove anything make sure its not a banksy