Even older than the sheathing methods were the various graving and paying techniques. There were three main substances used: White stuff, which was a mixture of train oil, rosin and brimstone; Black stuff, a mixture of tar and pitch; and Brown stuff, which was simply brimstone added to Black stuff. It was common practise to first apply wood sheathing and then pay it with white stuff, although black stuff was occasionally used in this way.
The use of copper sheathing was first suggested in 1708 by Charles Perry, though it was rejected by the Navy Board on grounds of high cost and perceived maintenance difficulties. The first experiments with copper sheathing were made in the late 1750s, at which time the bottoms and sides of several ships' keels and false keels were sheathed with copper plates.
In 1761 the experiment was expanded, and the 32-gun frigate HMS Alarm was ordered to have her entire bottom coppered, in response to the terrible condition in which she returned from service in the West Indies. Before the copper plates were applied, the hull was first covered with Soft stuff, which was simply hair, yarn and brown paper. The copper performed very well in protecting the hull from invasion by worm, and in preventing the growth of weed, for when in contact with water, the copper produced a poisonous film, composed mainly of oxychloride, that deterred these marine creatures. Furthermore, as this film was slightly soluble it gradually washed away, leaving no way in which marine life could attach itself to the ship. However, it was soon discovered by the Admiralty that the copper bolts used to hold the plates to the hull had reacted with the iron bolts used in the construction of the ship, rendering many of them near useless. In 1766, due to the poor condition of the iron bolts, Alarm's copper was ordered to be removed, and was not replaced.
After this experiment, and deterred by the unanticipated (and not understood) electrolytic reaction between the copper and iron, Lead sheathing was tried again, though it was found to be unsuitable to the task, as the plates tended to fall from the hull alarmingly quickly. In 1769, another attempt was made at coppering a ship's hull, this time on a new ship that had been constructed using bolts made from a copper alloy. The results were far more favourable this time around, but the onset and intensification of the war with America prevented the re-bolting of the Royal Navy's ships, necessary to allow a full scale coppering programme.
It was decided that the entire fleet should be coppered, due to the difficulties in maintaining a mixed fleet of coppered and non-coppered ships. 82 ships of the line had been coppered by 1781, along with 14 50-gun ships, 115 frigates, and 182 unrated vessels. By the time the war ended in 1783 problems with the hull bolts were once more becoming apparent.
Finally a suitable alloy for the hull bolts was found, that of copper and zinc. At great cost, the Admiralty decided in 1786 to go ahead with the re-bolting of every ship in the navy, thus finally eliminating the bolt corrosion problem. This process lasted several years, after which no significant changes to the coppering system were required, and copper plating remained the standard method of protecting a ship's underwater hull until the advent of modern anti-fouling paint.