Succesful, environmentally friendly paint removal is difficult. One the one hand there are the paint removal chemicals their makers
claim to be 'food grade' i.e. you could eat them without harm, and on the other hand there are the chemicals that can easily blind
you or blister your skin (Dicloromethane/Sodium Hydroxide) if you are foolish enough not to be wearing protective equipment.
The problem lies in the fact that the safer the chemical the less effective it is as a stripper.
An understanding of paint chemistry and the graffiti artists arsenal of materials as well as a comprehensive understanding of the
suitability, effectiveness and dangers of a particular paint removal chemical are crucial to succesful removal. Tests and trials are
essential in establishing the right methods in order to remove the offending coatings safely, succesfully and as quickly as possible.
It is often necessary to use combinations of techniques and materials to achieve the desired result.
Questions also arise about whether or not paint should be removed. The Conservator must be aware that what the client wishes to
remove may in fact be a culturally valuable example of street art or a historic piece of signage. When removing paint from historic
masonry and other surfaces analysis should be undertaken to determine the provenance of the paint. Was the building/monument/statue
previously decorated and if so will removing the surface paint destroy evidence of the previous decoration?
There are a range of products marketed today that can be used as post-cleaning surface coatings that act as an easily cleaned sacrificial
coating should the problem of grafitti re-occur (as it often does).
(An English Heritage publication about the removal and prevention of graffiti can be found here)