< ANTIQUE PAINT FINISHES
OIL PAINTS
Artists’ oil paints can be applied to copper alloy casts provided the correct preparation and finishing processes are well observed. It is possible to apply most oil bourne pigments to the cast without first applying a PRIMER COAT. This might be done if the paint is to be applied in a thin GLAZE, thus making a visible feature of the underlying cast’s metallic surface. The surface of the cast however, must be scrupulously cleaned and degreased before any oil pigment is applied. Better still if a primer is first applied to the surface of a SHOT BLSTED cast. A standard oil primer suitable for use on canvas will suffice, the more resistant this coating is, the better.
One of the limiting factors in using artist’s oil paints on copper alloy casts is the need to allow the applied layer (or layers), of paint to completely dry before any VARNISH protection is applied. Oil paint usually surface dries in three to four days, but a thorough drying-out may not occur for at least six months to a year, even more if a heavy IMPASTO technique is used. Only after complete drying should a varnish finish be applied over the paint layer, this obviously has some practical implications in terms of the waiting time involved [ref ].
A standard picture varnish can be used as a paint protection if the sculpture is to be exhibited indoors. This type of varnish has a relatively soft resin body which can be cleaned off and renewed if a superficial discolouration develops with age. For out of doors display, a harder and more durable POLYURETHANE VARNISH is preferred, though in this instance the coating is much more problematic to clean off and restore should this become necessary. In addition it is worth knowing that some lacquers can ‘yellow’ with age. Soluble FLURO POLYMER COATINGS have a 20+ years life before discolouration and also have excellent weathering and UV resistance qualities, though no information was available at the time of writing on the compatibility and longevity of these coatings when applied to painted metal surfaces.
Oil based paints can be applied to thin gauge sheet metal, but with care as some warping can occur, especially if thick impasto layers are deposited. ACRYLIC PAINTS are not considered suitable for application to copper alloy casts as the water content in the paint body tends to encourage OXIDISATION of underlying metallic surfaces, this type of reaction can eventually disrupt the deposited coating.
COMMERCIAL PAINTS >
|
