COOKING OIL AND VEGETABLE CLEANING AGENT

For most of the uses for which one used to use naphtha (turpentine substitute, white spirit, etc.) - cleaning inked plates, tools, brushes, inking slabs, hands, or any surface covered with oil-based printing ink - the simplest substitute is a two part process - first use vegetable cooking oil, and then biodegradable domestic washing-up liquid. I use sunflower oil, as it is inexpensive in France, but there are others which have the same effect and may be cheaper in other countries. Vegetable cleaning agent (VCA) can be used instead of the domestic detergent (see below).

The effect of the oil is to dissolve and thin the ink allowing it to be easily removed. To clean an inked plate, first pour a little pool of oil in the middle of the plate, and rub it all over with fingers, and if the plate has deeply bitten areas, use an old toothbrush, to get the oil well into the crevices. Leave it for fifteen to twenty minutes and then wipe off the dissolved ink. Repeat the process if necessary, before cleaning the oil off the plate with domestic detergent liquid, preferably the biodegradable kind. The cloth or absorbent paper used to wipe the plate can be used to wipe palette knives, inking slabs and fingers. Rub clean oil into hands to remove ink residues, then wash with soap and water.

There are sometimes occasions when very stiff ink, or slightly dried ink is difficult to completely remove, and that is when you can use Vegetable Cleaning Agent (VCA) to dissolve it. Pour a very small amount in the middle of the plate and spread it with a plastic spatula (I find that VCA is not kind to the skin). Unlike cooking oil, VCA can be left on the plate for much longer to dissolve the ink, then used as a temporary protection against oxidation if the plate is going to be used again soon. But if plates are to be stored for a long time, clean them with biodegradable detergent, and brush them with a thin film of Vaseline oil, and wrap them in clingfilm.

VCA is now being promoted all over the European Community as a replacement for volatile cleaning solvents in the printing industry. It is now increasingly available in most European countries, and I can recommend it most strongly. It can also be used for cleaning traditional hard and soft grounds and some quick drying oil based varnishes, which cannot be cleaned with vegetable cooking oil (18).

Dried ink that has been used for a ground or to produce a fractint can also be cleaned with VCA. Normally if you have been using fractint and stopping out areas with a ethanol based shellac varnish, then you will have to remove that with ethanol (ethyl alcohol), and a lot of the ink ground will come off with the alcohol. But do not use “denatured alcohol” which usually has a high proportion of methyl alcohol. Any ink ground residues that are left will probably come off after being left to dissolve in VCA. Failing that, acetone may be used, avoiding contact with skin and in a well ventilated space. Both alcohol and acetone are highly inflammable and while they are being used, and if there are any fumes detectable in the atmosphere, do not strike any lights, smoke, or do anything with electrolytic equipment that may cause a spark. If alcohol, VCA or acetone will not remove very old dried ink in etched lines, then the only solution is to use caustic soda. But it is a very strong alkali, is extremely corrosive and must be used with the greatest care, obeying the safety instructions to the letter, using suitable gloves, avoiding contact with skin and eyes. (TOP)