1. Chemically supported graffiti removal using high pressure hot water washing
Range of application:
This technology is used for gentle removal of dried spray paint from masonry and other surfaces.
Proceedings:
- Put cleaning paste on the surface and let it take effect. Paint will soak and/or strip off!
- After setting the dials of the high pressure equipment according to the instructions of the manual the dissolved paint is to be washed off carefully. (The paste in excess should be removed by hand in order to avoid any environmental contamination such as water pollution)
- In case that paint remains in the pores of the surface, repeat the procedure!
Settings:
In general when working with this technology it is advisable to use a hot water high pressure cleaner with a high pressure slit nozzle, lance and a protection against splashing.
Operating instructions:
water pressure < 120 bar; water temperature approx. 80°C/176°F
2. Abrasion using high-pressure hot water washing on protected (coated) surfaces
Range of application:
This technology is used for gentle abrasion of graffiti off surfaces that are protected by barrier coatings (TRB).
Assembling directions:
Basically the technical solution consists of a typical high-pressure cleaning system supported by a fuel-heated “Hot box” where the temperature may be increased up to a certain level in order to warm up the water, and an industrial wet cleaner. The operrating instructions depend on the temporary barrier coating-system!
Procedure:
Handling depends on the barrier coatings.
- After setting the equipment according to the manual the surfaces may be rinsed so that the area can warm up and, if required by the barrier, the coating can soak.
- Then the abrasion can be started.Now direct the hot water blast in a lateral angle to peel the poorly adhesive graffiti.
Health and safety considerations:
Protective equipment has to be worn and used (protective clothing, gloves and goggles etc.) Do not direct blast onto parts of the body!
Operating instructions:
Water pressure between 20 – 40,0 bar; Temperature between 60 – 95°C/140°F-203°F
3. Mechanical graffiti removal using low-pressure wet blast proceedings
Range of application:
This technology is used for gentle removal of dried spray paint off masonry.
Assembling directions:
Basically this appliance consists of a blasting nozzle, a water hose and a blasting hose for the air/blasting agent mixture, the controlling line, the low pressure blasting tank (at the same time blasting agent tank) and various fittings.
Handling:
Pressure and water have to be optimised in corresponding proportion, then blast from different angles. Paint in the pores is not removable without any mechanical detraction.
Restrictions:
After cleaning the masonry may show some shadows, this especially applies to those masonry units coated with dispersion paint. These shadows appear because of the difference in colour between paint pigments and mortar colouring. Blastering masonry guides to lay open some plastering elements.
Operating instructions:
Air pressure 0,1 – 3,0 bar
Water pressure 1,0 – 6,0 bar
Blasting agent filling 20 – 60 kg
Blasting agent consumption 2 – 5 kg/m²
Blasting agent hardness (referring to Mohns)
Calcite powder 3,0
Stone powder between 3,5 – 4,5
Glass powder between 5,5 – 7,0
(The Hardness depends on the product that has been used.)
Strahlmittelkörnung
blasting agent granulation 0,03 – 0,09 or 0,09 – 0,25
4. Manual graffiti removal off non-porous (smooth) surfaces
Range of application:
This procedure is used for the technically less large-scaled removal of dry spray paint from porous and smooth surfaces.
Proceedings:
- Put cleaning paste on the surface and let it take effect! Paint will soak or strip off (It is possible that it partially penetrates into the substrate of the masonry).
- Layer of paint and cleaning paste have to be intensively rubbed in.
- Remove the mixture consisting of paste and dissolved paint with an absorbent cloth!
- Rinse the surface well with water!
5. General information
- Before starting to remove graffiti, test the cleaning techique on the masonry concerned on a mock-up or on a somewhat hidden part of the masonry, but which are representative of the surface to be cleaned.
- Wearing appropriate protective clothing must be strictly enforced, e.g. protective chemical-resistant gloves, face shields and other protective equipment. Smoking, eating and open fire must not be allowed when cleaning is in progress.
- Environmental protection obliges to dispose the tissue that is contaminated with dried spray paint correctly using refuse incineration. Waste water may be passed into the sanitary sewer, but be assured of the indirect conduction regulations given by the respective country and/or county.
