Many different dressings are used by fishermen to preserve their sails and to keep them supple in wet and cold weather. Light summer sails are usually barked or tanned. These are sometimes afterwards brushed over with paraffin (kerosene). The Brixham men use a complicated mixture of linseed oil, tallow, Stockholm tar, yellow ochre, etc. If yachts’ sails are to be dressed they may be either tanned, or dressed with oil and ochre.

Nets are barked by passing them through a boiling solution of cutch, one pound to each gallon of water. In 1902, I saw the late Dr. P. W. Hughes barking his nets and using bichromate of potassium as a fixer. I tried the same solution on some light sails with disastrous result. Later, I made experiments with samples of the lightest sail cloth to find a strength of bichromate which would fix the cutch without injuring the fabric. This is the recipe for light sails which are not too large for the copper.

Boil in a copper 12 pounds of cutch and 12 gallons of water. Dip the sail and let it soak for a few minutes. Then clean out the copper and boil 4 or 5 ounces of bichromate of potassium in 12 gallons of water. Dip the sail in again. Then rinse it in water to remove the bichromate. If the bichromate contains any free chromic acid it will destroy the sail. It is therefore well to test the solution with litmus paper. If the litmus paper turns red, add washing soda gradually until it just begins to turn blue.

Tanning helps to preserve a sail. It does not make it stiff or heavy. The tanned sail is of a brown colour which does not shew dirty marks. But the canvas will be nearly as absorbent as before, so that it is as stiff and heavy in wet weather as an untanned sail. In a small vessel it is convenient to have a balloon fore-staysail tanned, because it so often has to be stowed wet. It is useful for a dinghy’s sail also because it does not increase the weight.

Oil and Ochre.—The method often employed by sail-makers is to brush the sails on both sides with a mixture of linseed oil, ochre, and water. The ochre and water form an emulsion with the oil. When the water evaporates, the globules of oil and particles of ochre are spread over the surface of the canvas. But the oil only penetrates the fabric of the canvas very slightly, and the tablings not at all. It therefore does very little towards preserving the sails.

A good recipe for oil and ochre dressing is as follows:—Put in a copper 5 gallons of the best raw linseed oil and 1¼ pounds of beeswax. Heat it until it begins to boil. Then gradually add 20 lbs. Venetian red ochre and 10 lbs. “light purple brown” ochre, and boil for five minutes, stirring all the time. When cool enough, add 10 gallons of the best paraffin lamp oil. Spread the dry sails on a clean floor or a clean shingle beach. Keep the contents of the copper constantly stirred. Brush it on both sides of the sails with a large paint scrubber, working the mixture well into the tablings. The sails should be temporarily bent to spars and hung up to dry in an open shed. Two days later they should be moved a little so that the oil does not settle in one place. They must be well ventilated while drying: if left in a heap only for a few hours they may become heated, and rot. After a fortnight they may be spread in the sun to complete the drying process. These quantities will be sufficient for 800 or 900 square feet of No. 6 flax canvas, or for 1,200 square feet of cotton of equivalent weight. Lighter canvas will, of course, require less.

Since the War the ochres have been obtainable ground in linseed oil to a smooth stiff paste. This is much more convenient. Less linseed oil is added. The proportions now are ochre ground in oil 30 lbs., linseed oil 3 gallons, paraffin lamp oil 10 gallons, beeswax or paraffin wax 1¼ lbs. About 4 ounces of dryers may be used in cold damp weather.

These ochres give a rich red-brown colour. Very nearly the same colour may be got by using 25 lbs. Venetian and 5 lbs. Indian red. Venetian red alone gives a brick red colour. Yellow ochre may be used alone, but it gives an unpleasant colour if used with any other ochre. Linseed oil should be of the best quality, obtained direct from a reliable firm. The best clear paraffin lamp oil should be used, as it dries more quickly and leaves no unpleasant smell behind. Oil and ochre, of course, add to the weight of the canvas. Sails dressed by this method are durable, supple, and waterproof so that they do not become stiff and heavy in wet weather.

New sails should not be dressed until they are fully stretched. It is generally best to keep them white for the first year. If one has a crew or plenty of leisure to take care of the sails it is seldom worth while to have them dressed.

I have used this recipe many times before the War and have never had any trouble: for example, the sails of Ianthe II. were dressed by this method in 1905 and were still serviceable in 1914. I have heard of cases since the War, in which sails have been found to be rotten almost immediately after dressing with oil and ochre, but I do not know what methods were employed.