Oakum
Oakum is a preparation of tarred fibre used to seal gaps. Its main traditional applications were in shipbuilding, for caulking or packing the joints of timbers in wooden vessels and the deck planking of iron and steel ships; in plumbing, for sealing joints in cast iron pipe; and in log cabins for chinking. In ship caulking, it was forced between the seams using a hammer and a caulking iron, then sealed into place with hot pitch.
Archibald Cochrane, 9th Earl of Dundonald
Cochrane hoped that he would be able to sell tar as a sealant for the hulls of ships to the Royal Navy. After contacts with the British Admiralty were made, a test was performed on a buoy. The buoy was coated on one side and left uncoated on the other. After some time the uncoated half was leaking and full of worms and barnacles, while the treated half was in quite good condition. A patent for his invention was drawn up, while the family estates were used as collateral.