The ‘perfect gold dredge

Press, 26 January 1980, Page 1

The ‘perfect gold dredge

Dreams snine golden these days, and the country is full of would-be prospectors. But two Christchurch men store their gold in little bottles rather than in dreams. After years of experimenting Mr Jim Mawdsley, of Sumner, and Mr Case van Beek, of Wainoni, feel they have perfected a portable, easily worked gold dredge. The first time they tried it, early in December, they recovered 58 grains of gold worth about $lOO, and all for only two hours work.

But last evening, a demonstration of the gold dredge in the Waimakariri River produced only a lead pellet from a slug gun. Gumbooted and up to their elbows in dirty water, the two men put their dredge into action. The two-stroke motor pumped water through a hose into a stainless steel pipe to jet away from a nozzle which drew gravel through its mouth. The water and gravel washed over a grid contained in an aluminium sluice box, and anything the weight of gold dropped through on to a coconut-fibre matting while the water and gravel washed out of the dredge. Disconnected from the nozzle, the hose can squirt water about 28 metres, and has a pressure of more than 620 kilopascals (90 Ib/sq in). Suction through the nozzle can work the dredge upstream as the gravel in its path washes through and out the other end.

The whole dredge, together with a day’s supply of petrol, two lunch-boxes and a gold pan weighs about 58kg, and can be carrieid comfortably by two men. The engine is fitted on a back-pack frame.

Five years ago Mr va,n Beek took up gold panning when on holiday in Arrowtown. He began experimenting with homemade dredges, and two years ago Mr Mawdsley joined the project. Since then they and their families have enjoyed many happy hours with their hobby.

In spite of success, Mr van Beek and Mr Mawdsley intend to keep gold prospecting as a hobby and try to market their dredge instead.

“We both have our own jobs, and being married with our children still at school, we can’t just pack up and go. We can’t gamble with our families,” says Mr Mawdsley. “Anyway, 'we’d have to have a real claim first with everything set up properly.” The dredge cost a small fortune as it took many tries and swapping of parts to get the right combination. But they believe they could be manufactured for $l4OO to $l5OO each.

After answering advertisements to buy a gold dredge, it was found that a wait of about two months would be necessary for parts to come from overseas, so they worked on one of their own. Now they feel it is unnecessary to import parts when dredges can be made in New Zealand.