CUTTY SARK. A Section of one of the Muntz metal plates removed from the bottom of the hull of the "Cutty Sark" in the course of repairs to the ship in 1963. Greenwich. The Cutty Sark Society. 1963.
330 x 335mm approx, with irregular edges and several holes, some oxidation and patination, preserved in custom-made cloth flapcase with leather label.
With original certificate of authenticity, stating this is no. 15 of an unstated limitation, signed by Henry Barraclough, Chairman of the "Cutty Sark" Society.
Also with a copy of the 1953 "Cutty Sark and the Days of Sail" exhibition catalogue, and a copy of Frank G.G. Carr's The Story of the Cutty Sark (1972).
During ongoing restoration to the Cutty Sark in 1963, 289 sheets of Alumbro were used to replace badly dezincified Muntz metal sheets, some of the original sheets being offered for sale.
Muntz Metal is a form of alpha-beta brass with about 60% copper, 40% zinc and a trace of iron. It is named after George Fredrick Muntz, a metal-roller of Birmingham, England. Muntz commercialised the alloy following his patent of 1832, although William Collins had patented a 56:44 alloy in 1800.
Its original use was as a replacement for the copper sheathing placed on the bottom of boats, as it maintained the anti-fouling abilities of the pure copper. As it cost around two thirds of the price of pure copper and had identical properties for this application, it became the material of choice and Muntz made his fortune. Later it was used to sheathe the piles of piers in tropical seas, as a protection against teredo shipworms, and in locomotive tubes. Muntz Metal is still the term this form of brass is known by. It is a form of brass that must be worked hot and is used for machine parts that must be corrosion resistant.
After successful experimentation with the sheathing Muntz also took out a patent for bolts of the same composition and these also proved a success, for not only were they cheaper they were also very strong and lasted longer. The hull of the Cutty Sark was a notable use of Muntz Metal.