geo2
Member
Posts: 5 
|
Post by geo2 on Dec 4, 2014 21:06:07 GMT 12
Greetings Rob I see there are some dredges in the pics you posted about in this thread : golddredgingforum.proboards.com/thread/637/alluvial-pacific-dredgeshas some (visual) similarity to the (Suitcase Dredge) designed and built by a Kiwi miner called (Trev Alty) , who also created what Mike Pung of the USA has improved upon and sells as the (Gold Cube). Trev known also as "Kiwigold2001" has built a simple and affordable 6 inch dredge that works ! I think he named it that way cause the latches on the sides resemble those of a suitcase  I want to build a 6 inch dredge as building a 2 inch is a waste of time and efforts. I know of several places to be good to use one. Any ideas or helpful tips for building such device and if anyone has built one and used it, what do you think of it ? Thanks. |
|
|
|
Post by RKC on Dec 4, 2014 22:36:54 GMT 12
G'day geo2, Suitcase dredges are ancient history in New Zealand. At this moment in time there must be hundreds of them sitting gathering dust in garages all over New Zealand. I haven't seen a single one advertised for sale for years, and the last one I saw was a few years ago in a second hand shop in Greymouth. I doubt you could even give one away these days! They were sold originally by at least two manufactures in the South Island. There was a guy in Christchurch, during the 1980s, who was a metal fabricator who sold them from his shop which was located in the center of Christchurch (which I visited once just before he closed). They were also manufactured and sold from the Gold Shop in Arrowtown. The Kiwi version was based on a dredge an American guy who sold dredges in Australia tried to sell in New Zealand when he visited New Zealand in the 1980s. The dredge the American tried to get agents for in New Zealand was his own copy of an American dredge (can't think of the brand name at present but it might come to me later). His dredge was a 5" that looked much like the Kiwi Suitcase dredge turned out to be. The Kiwis who he tried to get to be agents to sell his copy came to the conclusion that they could make their own version, and therefore they did not need him. If they had exactly copied the dredge the American was trying to sell in New Zealand the Suitcase dredge might not have turned out to be such a dog of a dredge. The big mistake the Kiwi copiers made was to increase the suction hose size from 5" to 6". Having a 5hp motor run a 6" dredge (even if it could be a subsurface dredge) was a ludicrous concept destined to fail from the word go. Then they further made suction less efficient by using an easily purchased suction hose that did not have a smooth bore (the hose they used had wide corrugations which reduced suction efficiency significantly). The suction at a depth of more than a few feet was so poor I've seen this dredge unable to suck up reasonable (but not large) sized lumps of gold sitting in clear view on the schist bedrock. One guy (Alan Hamilton) who used one on the Arrow river in the 1980s used it in shallow rapids to remove shallow overburden to expose the gold on bedrock which he would then remove by hand. I once worked together with a guy on the Arrow river who had a suitcase dredge, and we worked his dredge and mine, which was a conventional 4" surface dredge, side by side going upstream (photo below) working the same face as we went. He used to mock me when I told him he was losing most of the gold out the back of his dredge. He liked the portability so I didn't push it. Until, one day after we had lunch and were going back to the dredges I convinced him to do a few pans from his tailings pile. His eyes popped out of his head when he saw the color in his pan that should still have been in the Suitcase dredge. If I remember correctly I think he then commenced to redredge his tailings. He didn't use the Suitcase dredge much longer. I reference the inefficiency of Suitcase dredges in this article sites.google.com/site/coocheegold/Regards, Rob (RKC) Attachments:
|
|
|
|
Post by RKC on Dec 4, 2014 22:42:34 GMT 12
G'day, The Kiwi Suitcase dredge (from a newspaper article). Regards, Rob (RKC) Attachments:
|
|
|
|
Post by RKC on Dec 4, 2014 22:46:51 GMT 12
G'day, The last Suitcase dredge I've ever seen working in a waterway (In the Cardrona river, Otago. More than 10 years ago). Regards, Rob (RKC) Attachments:
|
|
|
|
Post by RKC on Dec 4, 2014 23:55:50 GMT 12
G'day geo2, This Gold Cube thingie you reference seems to be a compact variation of a Shetland Islanders beach box, made for modern day hobby fossickers. Shetland Islanders mined the beaches of NZs West Coast near Westport in the 1800s. They developed a style of beach box that was still used until recent times. Essentially they were long tables with sunken trenches every few feet along the length into which slats were inserted (see pictures below). The sole purpose of the slats was to slow the speed of the water down.  Great idea and a simple idea, and they have been used up until recent years by modern day West Coast miners (I have some photos somewhere of the modern day versions and I'll try to find them when I get a chance). Shetland Islanders beach box's have previously been mistakenly refereed to as boil-box's. Boil-boxs are sumps placed at the head of a sluice box as a nugget trap. They are extremely common all over the world and all miners know boil-box's are only nugget traps. imagizer.imageshack.us/v2/563x383q90/908/Y4ZOEY.jpgRegards, Rob (RKC) |
|
|
|
Post by RKC on Dec 5, 2014 0:27:51 GMT 12
G'day geo2, I found the photos. This Shetland Islanders beach box was being used on the West Coast in 2007. Regards, Rob (RKC) Attachments:
|
|
geo2
Member
Posts: 5
|
Post by geo2 on Dec 5, 2014 1:53:59 GMT 12
Hi, Thank you very much Rob, I didn't know there is such a long history of this dredge in usage  The suitcase dredge builder I am referring to (Trev) has stated that the concept was first taken from an American made portable dredge (a Keene Submersible) and to quote his words "A Kiwi modified it to become the Suitcase Dredge.He has visited Keene Engineering and explained it all to them. They were most intrigued and had him make plans etc. As they said it brought a new dimension into portable dredging units. I figure they worked out it was so cheap for the home handyman to produce, that should they have purchased a retail version it would have been copied overnight and they would have no sales" . Granted they are no good at fine gold recovery with such big riffles and aggressive water over them there is no way for fines to settle. |
|
geo2
Member
Posts: 5
|
Post by geo2 on Dec 5, 2014 6:13:17 GMT 12
Hi Rob,
I guess those "Shetland Islanders" beach boxes are common down there. What type of lining do they use? is it ribbed rubber matting or are they just plain slats with no linings on them ?
The (Gold Cube) super concentrator is based on a study of a beach box by (Trev Alty) of New Zealand. It works on a similar principle , only the difference is that the (Cube) uses a rough top conveyor belting material (some times it is called Vortex Matting). This is a bed lining material covers the slanted sloped troughs , much like the beach boxes you showed the pictures of.
|
|
|
|
Post by RKC on Dec 5, 2014 8:13:37 GMT 12
G'day geo2, The American dredge manufacturing company (I mention above) that sold the dredge that was the original inspiration for the Kiwi Suitcase dredge was one of the smaller companies (it certainly was not Keene). The dredges they sold were sold under the brand "Ultralite/Ultralight" dredges ... so, it could have been the Ultralite dredge company. Subsurface dredges were nothing new to Keene at any time in the history of the company. Keene have sold subsurface dredges from when they first started the company in the 1950s. And they might even be still selling them today. The dredge that Ernie Keene first used well before deciding to go into business selling dredges was a subsurface dredge similar to the Suitcase dredge. The first men to use Suitcase dredges in NZ would have been those who sold them commercially (as previously mentioned). I'm not aware of anyone using a Shetland Islanders beach box for beach mining presently. A typical Kiwi beach box in use these days is shown in the photo below. The beach box you say the Gold Cube is based on is simply a Shetland Islanders beach box. Regards, Rob (RKC) Attachments:
|
|
|
|
Post by RKC on Dec 5, 2014 8:28:20 GMT 12
G'day geo2,
On further reflection, I think the dredge might not have been called the Ultralite after all. I think it was the Mighty-Lite. There were 7" and a 5" models sold.
Regards,
Rob (RKC)
|
|
|
|
Post by RKC on Dec 5, 2014 8:35:32 GMT 12
G'day geo2, The dredge I was trying to think of was the Mighty-lite, not the Ultralite. Regards, Rob (RKC) Attachments:
|
|
|
|
Post by RKC on Dec 5, 2014 12:07:12 GMT 12
G'day geo2, A suitcase dredge in the Arrow river, Otago during the 1990s. Regards, Rob (RKC) Attachments:
|
|
|
|
Post by RKC on Dec 5, 2014 12:10:03 GMT 12
G'day, Dredge from California in the 1950s. Regards, Rob (RKC) Attachments:
|
|
|
|
Post by RKC on Dec 5, 2014 12:47:16 GMT 12
|
|
geo2
Member
Posts: 5
|
Post by geo2 on Dec 6, 2014 8:34:26 GMT 12
So they are not good at all, right? Rob, the problem of building a dredge from scratch for some folks -me included- is finding the right parts (the pumps and the compressors especially) with not high price tag. Think of importing most of these and adding the costs of customs, taxes ...etc
Eventually building a dredge using what you have is the sole route to some people unless these hurdles can be overcome. Then the whole lot of tseting and re designing's and testing and time and frustrations ! A lot of hassle involved 
|
|
