Maintaining your Sculpture
Maintaining your Sculpture including Outdoor Placement
The cast marble requires hardly any maintenance indoors, and all it does need is a good wipe occasionally with a perfectly clean, and very soft cotton cloth. It is a highly polished surface, and just like your sun glasses, if it gets a smudge on it, then the polish will look dull. That will happen by itself over time, just from things in the air. Mostly though it comes because people like to touch them. Unlike natural marble, which is very porous, and which is why they don’t like you touching them in museums, the cast marble has been saturated with the resin that we re bond it with. It will not absorb body oil, except marginally on the rough unpolished areas. All you need to do is wipe it with a clean cloth periodically to keep it looking as new.
Generally though marble sculpture normally requires no maintenance except for cleaning. Do not use abrasives on polished surfaces and do not use cleaning agents containing methylated spirit or alcohol on bronzes that have been lacquered as this will react. Periodic waxing will help to maintain the polish on bronze sculpture placed out of doors, and will do the same on cast marble outdoors. It is not advisable to use any waxes, even light ones like Mr. Sheen, as this will stain natural marbles.
However all marbles, whether natural or cast will lose their high gloss polish if subjected to prolonged action by the elements. There is also a chance that cracks may develop on marble sculpture placed outdoors, due to thermal expansion caused by heat but apparently not cold. Cold and snow does not seem to bother it, as evidenced by pieces placed in high latitudes over several winters. But the artist knows of one case only over thirty years, of a black piece placed in the sun in the desert of the southwest USA, and it did develop one crack.
But to maintain that nice glossy polish and colour it is possible to coat a marble sculpture placed outdoors with a clear lacquer (two pack is best) that will protect the work from any surface dulling, as long as the lacquer stays good. You should wax any bronze or cast marble outdoor sculpture, even if lacquered, as this will become the sacrificial part, Use a carnuba based wax, such as “Mothers Wax”, not a silicone based one. Your local panel beater (auto body repairman) or professional painter is the recommended person to contact for clear coatings. Cast marble is more resistant than natural stone as it does not have the tiny cracks, fissures, and pores that natural stone has. It is normal for black cast marble to take on a gray shade when the polish wears off. If you want to place your piece in direct sunlight and rain, and you want to keep that nice polish with all the vivid colouration, you need to have it clear coated. Out of the sun and rain, such as under an eave, is not a problem.
If you spill oil, or red wine on the rough parts, and the stain won’t come out with cleaning agents (don’t get these on the polished parts), then what you need to do is to scratch the surface back to that frosty white. The point of a knife or a small screw driver like the ones used for glasses works a treat. Just scratch away the stained surface to expose the fresh material underneath. Slight scratches from jewellery, etc., are easily dealt with by applying some black shoe polish and then buffing off. Don’t use that trick on white marbles, use white shoe polish instead. Should your piece ever be damaged, if all the broken bits are saved it is possible to repair it without any apparent evidence of damage. It is hoped that you get a lifetime of pleasure from the artwork.