The decision of cleaning ironwork must be based on a
genuine necessity. For eg. something which is darkened with soiling,
biological growth and metallic staining, is not only disfigured but also
exposed to deterioration and hence requires cleaning. A lightly soiled piece
with legible details however does not require major cleaning.
In the cleaning process, these pieces are sand blasted or shot blasted to
remove accumulations of the multiple layers or paint which have usually
obscured much of the original detail. This access to the underlying metal
also allows to correct defects frequently found in the original ironwork.
Careful cleaning is also useful in revealing structural defects that might
require attention prior to refinishing. Good bonding of any applied finish
occurs when the corrosion layers and corrosive salts are removed from it.
Paint removal must be carried out using chemical agents chosen according to
the type of paint and the need to avoid damage to the metal itself. After
the paint is removed, care should be taken to ensure that any chemical
residues are also removed or neutralized.
All the bare metalwork should be given a grey finish and wiped with acetone
to remove residual dust and oils. Cleaned ironwork must be immediately
treated with a quality inhibitive primer or coating to prevent the formation
of rust which will interfere with adhesion of the new coating.