Story: Kauri gum and gum digging
Page 4 – The industry
Buying and transporting gum
Storekeepers were the main buyers of kauri gum. They ‘grubstaked’ many diggers – allowed them to buy supplies on credit, on condition that they sold their findings to the storekeeper. Once a week the storekeeper did his rounds, delivering supplies and buying gum.
Gum was laid out at the gum tip – a cleared area, often on a rise so that it received the sun and wind. The gum’s purity was judged, a price was decided and the gum was weighed. Horse-drawn carts and large bullock teams pulled the gum on sleds to the nearest port. It was loaded onto barges, coastal cutters and steamers, and shipped to Auckland. In the wet months, when Northland’s clay roads were boggy, transport costs often increased and supplies became more expensive.
Gum was unloaded at Auckland’s wharves and taken to the major buyers’ warehouses. It was then cleaned again and graded, ready for export. Gum was exported in boxes made from heart kauri, a high-quality timber that was often used to make furniture at the destination.
A major industry
Early Auckland was built on gum – a fact not always acknowledged. ‘Our gumfields are the Cinderella of our productive wealth,’ opined the 1913 prospectus of the inventors of a machine to clean gum. 1 From 1850 to 1950, gum exports totalled 450,000 tons, and from 1850 to 1900 gum was Auckland’s main export – ahead of gold, wool and kauri timber. Its total worth to the country has been estimated at around $300 million (in 2006 terms).
The gum trap
Few diggers made much money from gum. One reputedly told a visiting government official, ‘I dig the gum, to get the money, to buy the food, to get the energy to dig the gum.’ 2
Using low-grade gum
Gum was graded on its quality. Higher-grade gum was used in varnish, but around 1910, overseas manufacturers began using poorer-grade gum to make linoleum. A market was created for low-grade gum, including small pieces known as gum nuts and chips, and the previously worthless scrapings and dust.
New techniques were needed to recover small gum pieces from soil and swamps. Water-filled drums with screens – called hurdy-gurdies – washed away the soil and left behind the gum and bits of wood. Where large areas were dug over, pipes poured muddy water onto screens and sieves, and men agitated the mixture to wash away the soil. It was muddy, wet work. By the 1920s, new machines – basically larger oil-driven hurdy gurdies, used by teams of men – could process a lot more raw material.
The material that was left after washing – gum, stones, bits of wood and debris – was dried in the sun. Then it was winnowed by throwing it in the air. A breeze carried away the lighter pieces, leaving gum behind. Later, winnowing machines were built, along with machines to separate the gum from worthless material, and to clean it. Gold mining techniques were trialled – in the late 1910s a disused Otago gold dredge worked a swamp near Awanui, but without success.
End of the industry
In the 1930s cheaper synthetics were developed for making varnish and linoleum. The price of gum fell, and by the 1940s it was a sunset industry. In 1985 a processing plant was built at Kaimaumau, north of Awanui, to extract resins and waxes from kauri chips and dust from a peat swamp, but it had technical problems and closed in 1989.