GRAFFITI

1. LINEA GRAFFI’ v5.1 GRAFFITI First Part General information

2. Anti-graffiti Treatment In most cases the damage is done on unprotected surfaces. Graffiti problem is faced by means of empirical methods and unsuitable techniques. The proper solution must come from a series of steps which will give the antigraffiti system. Diagnostics preparation of intervention Identification of graffiti Characteristics of materials Operative tests Site logistics Schema generale Physical-mechanical methods Sandblasting, pressure washing, waterjet sandblsting, low-pressure centrifuge washing, laser, etc. Chemical methods Solvents, paints removers, poultices, cleaners Removal of graffitis Antigraffiti protection Cleaning graffitis From protected surfaces

3. Diagnostics • The identification of graffiti to be removed is the complement to the most efficient removal methos: this can be determined with preliminary testing. • The features of the material (stone, marble, bricks, plaster, wallpaints, etc) are critical at the same way: • physical properties of the surface (roughness, porosity) • resistance to washing (water absorption, sensitivity to alkaline/acid detergents, sensitivity to solvents) • mechanical properties (hardness, resistance to high-pressure waterjet) • These features must be related to the state of conservation and to the possible artistic relevance: this will affect the operative logistics and the choice of cleaning technique and of protection needed. diagnostica

4. Literature * Interventi Antigraffiti: Proposte e progressi sulla ripulitura e protezione delle superfici. Il punto della situazione sulla ricerca e sulle tecniche antigraffiti. A.Granato et al., GEAL srl, Incontri Tecnici Restauro 1999 e 2000, Ferrara – in collaborazione con CNR Firenze e Syremont spa Protezione Antigraffiti, studio preliminare. S.Galbiati e C.Garavelli, Politecnico di Milano, Incontri Tecnici Restauro 2001, Ferrara – in collaborazione con Geal srl e Istituto Centrale di Restauro, Roma Protezione Antigraffito, una ricerca sperimentale. S.Galbiati e C.Garavelli, Recupero e Conservazione, 2001, n.40-41 diagnostica *Issues are in Italian language

5. Materials and surfaces Porous and absorbing stone In some particular cases it is not possible to wash intensively with waterjet, like here in the historic centre of Florence, Italy. The stone is teh traditional Pietraforte sandstone in a façade of a 16th century florentine palace. Heavy encrustations of altered material and urban pollution deposits can be easily removed by an extracting poultice. Left: result after one application only. Cleaning volcanic tuffstone, extremely absorbing, can result very difficult. Cleaning unprotected surfaced could be almost impossible without causing damage to the stone. It is always needed to clean perfectly the surface before applying antigraffiti protection. Photo: wall covering made of Vicenza Stone (calcareous sandstone) with topical deposits of dark mildew. TECHNICAL REMARK Travertine is not an absorbing stone, but natural cavities present on unfilled surfaces will make extremely hard its cleaning.

6. Materials and surfaces Mixed materials Up and left: 2 very common cases of graffitis overlapping and/or drawn on different materials (bricks, concrete, painted metal, glass). Correct management of the working site must foresee preliminary tests to determine products and cleaning steps. Down: glass-tessera mosaic. Cleaning of tesseras is generally very simple, but could be difficult to clean light-coloured grouts without damaging.

7. Materials and surfaces Plaster and concrete Cleaning graffitis could result the most expensive intervention in terms of manpower, equipment, products. It is absolutely needed to carry out prelimary tests in order to determine the practical effectiveness and costs. In many cases re-making plaster is the most acceptable economic solution, when the antigraffiti protection was not made before. Up: uncontrolled use of aggressive detergents can make it worse, with colour casting and absorption of dissolved paints. Down:damage caused by a normal high-pressure washer on a traditional plaster surface

8. LINEA GRAFFI’ v5.1 GRAFFITI Second Part Anti-graffiti intervention

9. Removal Removal of graffitis must be carried out by non-hazardous products and techniques to the operators and environment, neither destructive for the material MECHANICAL METHODS Sandblasting,sabbiatura, idrolavaggio, idrosabbiatura, etc. Packs with absorbant poultices made with a substratum (natural clay, paper pulp, etc.) + detergent laser : its use is limited to some artwork only Low-pressure centrifuge washing CHEMICAL METHODS solvents : liquid and gel detergents and bleaches MIXED METHODS Various techniques : e.g. detergent + pressure washer

10. Low-impact mechanical methods Damages caused by high-pressure sandblaster on a sandstone wall cladding Traditional pressure washing machines and sandblasters can provoke irreversible mechanical damage to the surfaces, caused by direct impact of abrasive with high pressure. Present trend is to subsitute traditional abrasives with those of low hardness and utilize equipments which generate variable helical-shaped jet, in order to get minimum pressure tangent to the surface and thus obtaining a controlled action. This market is expandind by reducing the costs of equipmet and of site management.

11. Chemical cleaning methodologies When tested to be effective, the chemical cleaning is the best method to avoid damages to the surfaces. Of course it should be recommended to respect operation sequence and products determined by prelimary testing. In the pictures 2 examples of intervention with liquid deter-solvents. In some particular cases and on porous materials it is advised to use chemical extracters with absorbing power, in order not to diffuse the dissolved colour into the material. Generally the use of extracters (poultices based on natural clay) is alternated with liquid detergents.

12. ANTIGRAFFITI PROTECTION Technical features Avoids grip of graffitis makes cleaning faster and easier Discouraging effect makes the adhesion of colours and paints difficult many competitors’ products are classified toxic or noxious, or use solvents with heavy environmental impact Products are not hazardous does not produce chromatic alteration after its application and after long exposure No visual impact Reversibility of the protective treatment, can be used on monuments and artworks Not filming saves the permeability to water vapour (breathing) the removal of graffiti can be carried out with fast non-hazardous cleaners Easy and unexpensive maintenance Versatility 2 products only to protect all materials

13. ANTIGRAFFITI PROTECTION Practical examples of application No sophisticated tool is required for the application of GEAL’s antigraffiti protectives

14. Examples of intervention ANTIGRAFFITI TREATMENT Statue and basement made of white Carrara marble Piazza Mercadante Naples, Italy Before End of the work, after cleaning and protection with GRAFFÍ SCUDO A step of removal with GRAFFÍ ESTRATTORE

15. Examples of intervention ANTIGRAFFITI TREATMENT Covering of a façade made of Pietra Serena sandstone Surface had been protected with GRAFFÍ DEFEND A step of cleaning with GRAFFÍ TERGENT

16. ANTIGRAFFITI TREATMENT Examples of intervention Wall covering of a tunnel made of Santafiora sandstone Underpass Fortezza da Basso, Florence, Italy – opened to traffic in september, 2004 Santafiora is a siliceous sandstione, coarse, rich in fossils and imprints of mud-eaters, with medium-high absorption The underpass tunnel as it looked before the work. Stone covering is laid both on the internal walls and on side exterior walls. Total stone surface is 3600 sqm ca. It was quoted to complete the job in 7 working days with 4 operators, in the optimum weather conditions. Some prelimary tests were carried out, in order to determine dosages and products to be applied. Accepted working proposal involved a preliminary washing with SERVICE ACIDO diluted, a protective impregnation with GRAFFÍ FOND, and a final antigraffiti protection with GRAFFÍ DEFEND This treatment will allow an easy maintenance and an immediate renovation of protection.

17. ANTIGRAFFITI TREATMENT Examples of intervention Wall covering of a tunnel made of Santafiora sandstone Underpass Fortezza da Basso, Florence, Italy – opened to traffic in september, 2004 Il tunnel dopo l’apertura al traffico veicolare a 2 mesi dall’intervento, durato materialmente 5 giorni lavorativi. L’aspetto naturale della pietra è rimasto intatto L’applicazione a spruzzo di GRAFFÍ FOND seguita dall’uniformazione. Una squadra di 2 operatori è sufficiente per coprire grandi superfici in tempi brevi. La pulizia preliminare con SERVICE ACIDO diluito al 20%, per eliminare le tracce di polvere di lavorazione della pietra, di posa, di pulviscolo atmosferico. Questo lavaggio è necessario per migliorare le prestazioni della protezione, come evidenziato dai test.

18. ANTIGRAFFITI TREATMENT Examples of intervention Exterior wall made of Pietra di Vicenza (soft limestone) Museum of Contemporary Art MART of Rovereto, Trento Application tests of protection by means of GRAFFÍ FOND and GRAFFÍ DEFEND, to verify the absence of chromatic effect For the whole outdoor covering a yellow variety of Pietra di Vicenza was used. The stone is a fossiliferous biocalcarenite (porous limestone) with a high absorption. Outdoor pavement is made of Tridentin Porphyry (hard stone, similar to granite). Total surface is about 20000 sq.mts of stone and 4000 sq.mts ca of porphyry: Both materials need preliminary cleaning to remove alterations.

19. LINEA GRAFFI’ v5.1 GRAFFITI Third Part GEAL's proposal

20. REMOVAL OF GRAFFITIS BY CHEMICALS for the complete removal from porous materials and residual spots (“ghosts”) GRAFFI’ESTRATTORE For the removal from painted surfaces or delicate surfaces, not resistant to acids, alkalis, solvents GRAFFÍ TERGENT Physical-mechanical methods also used In some situations removal can be made easier by using other Geal’s products:Estrattore Sverniciante, to remove thick paints and enamelsService Linfosolv, to remove graffiti from wood Estrattore Alcale, to remove uncommon graffiti made with lipstick, wax paints, etc.

21. REMOVAL FROM TREATED SURFACES GRAFFI’ TERGENT Neutral selective detergent Rinse can be manual or by pressure washer Carry out preliminary tests

22. Antigraffiti Treatment Graffì TERGENT Not needed on hard surfaces such as polished marble, ceramic tiles, etc PROTECTION Graffì FOND ON TREATED SURFACES Graffì DEFEND Graffì TERGENT For maintenance reapply GRAFFÍ DEFEND After any washing