BCM Course Leader
David is Director of Odgers Conservation Consultants who provide support, advice and training for clients, architects, surveyors, local authorities and others involved in the conservation of historic structures.
David is a tutor on the Coatings and Consolidants for Masonry course (30 March - 1 April) and Masonry Cleaning course (6-8 April), where you can learn how to safely and effectively remove unwanted soiling and staining, including graffiti, from historic buildings. Images below demonstrate removal from a C12th Reredorter ruin.
The removal was carried out using the following processes:
- Pre-wash with superheated water – removes some graffiti and pre-warms the surface in colder weather
- Apply Graffiti Remover Gel. Dwell time up to 1.5 hours with occasional paint brush agitation. This mobilises the binder and majority of pigment and which was then rinsed with superheated water (vacuum recovery attachment used in this case, due to the location – bats, fauna and river in the vicinity).
- Ghost Remover (hypochlorite). Applied to wet surface, dwell 10 mins. Removed with vac recovery.
- After wash (Acetic acid - white vinegar). Application as 3. The acetic proved to be more effective than hypochlorite in this example, such that 3 could have been omitted.