RESTORE YOUR PRECIOUS OIL PAINTINGS.
Damage to oil paintings come into several categories. The canvas may be torn or punctured by holes; or, if the painting is on wood, this may have split. Alternatively the varnish may have discoloured, mildewed or crazed, or the paint blistered or cracked.
An oil painting is composed of a number of layers. First there is the canvas made of linen, which is stretched and tacked round a wooden frame. Traditionally, the canvas is primed with a seal, made up of gesso or glue and water. Sometimes a coat of white lead paint is then applied. The picture itself is painted with pigments ground into a thick cream with linseed or poppy oil. This may be thinned further with more oil. Finally the picture is coated with varnish, which intensifies and protects the colours.
A painting on a wood panel is generally built up in a similar way but, whereas blemished canvas can be renovated wood which is split or damaged can only be repaired if you are skilled at retouching. Unfortunately for the restorer some artists do not work in a traditional fashion. All painters hope that they are working for posterity, but few are convinced that this is a definite possibility. Consequently, most tend to concentrate on the immediate demands of their subject and some use unconventional techniques in the process. In other words you cannot always know what has gone on between the canvas and the final coat of varnish. If the painting is intact, clean the grime off the surface of the varnish. There are many lubricants and solvents recommended for this but avoid linseed oil because it darkens, hardens when dry, proves completely insoluble when you want to clean it off and inconsequence, can only be picked away bit by bit. Use turpentine or white spirit only with the greatest caution because although these will lift dirt and grease, they dissolve some varnishes and if this happens, the original paintwork may be disturbed. Preferably, use a proprietary cleaner such as CRP or wipe the picture with a swab of cotton wool dipped in a cup of cold water containing ½ teaspoonful of ammonia. Your painting may be satisfactorily freshened by this treatment although the surface and colours still look dull. Either wipe a little wax polish over the finish and rub gently to a shine later or brush on a coat of synthetic resin varnish, which will not yellow with age.
DEALING WITH MILDEW- Due to being hung or stored in a damp atmosphere some pictures are mildewed. The fungus should be wiped off and a sheet of thick cartridge paper soaked in a 5% solution of sanobrite should be inserted between the canvas and the back of the frame to discourage further attacks. Pictures should be hung in a room, which is neither damp nor too dry. Keep them away from central heating and the heat from open fires or stoves, etc.
