New Zealand Gold Prospecting & Metal Detecting Forums Archive

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gavzilla		Posted : Saturday, 30 August 2014 4:40:40 PM(UTC)
Rank: Gold Nugget Groups: Registered Joined: 24/02/2012(UTC) Posts: 60 Location: queenstown Thanks: 12 times Was thanked: 34 time(s) in 18 post(s)		G'day guys, was thinking of getting one of those cheap Chinese trash pump engines off trade me (6.5hp) to make 4-5" dredge, just wandering if I need to swap the pump out or can I Venturi the trash pump? On a budget and I don't want to spend heaps on those Keene pumps. Or does anybody have one for sale? Ta.

NUGGY		Posted : Saturday, 30 August 2014 11:19:43 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 20/07/2012(UTC) Posts: 267 Location: greymouth Thanks: 85 times Was thanked: 76 time(s) in 58 post(s)		If you are on a budget I would suggest keeping an eye on Trade Me for a good Honda and Onga pressure pump combination. These work very well, and as long as they are in good order will last for years. If you go for the Chinese copy get one with a pressure rather than a volume pump. NUGGY

gavzilla		Posted : Saturday, 30 August 2014 11:38:38 PM(UTC)
Rank: Gold Nugget Groups: Registered Joined: 24/02/2012(UTC) Posts: 60 Location: queenstown Thanks: 12 times Was thanked: 34 time(s) in 18 post(s)		Cheers nuggy, do you have any other suggestions on dredge size ect. Not much experience in this area! I think I want to run a jet nozzle in the back of my sluice box via a traffic cone shaped flare type thingy. (Highly technical) I am not to serious on sucking up all forms of life through my dredge/high banker, most creeks I visit are less than a Meter deep! But could be the occasional big river.

NUGGY		Posted : Sunday, 31 August 2014 12:52:17 AM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 20/07/2012(UTC) Posts: 267 Location: greymouth Thanks: 85 times Was thanked: 76 time(s) in 58 post(s)		Have a good look through some of the old posts and photos on this site, KiwiJW has put up some good photos of budget gear he has made that looks like it works well. I find a venturi is handier in small creeks and easier to hook up to a highbanker type set up too. A 4 inch costs about the same to build as a 3 inch but will put through more material. I would go for a 4 inch to start with, tubing is easy to get too. A 5 inch is better still when it comes to moving material, but the tubing can be expensive and hard to find - also you need more water. NUGGY Edited by user Sunday, 31 August 2014 1:00:20 AM(UTC) \| Reason: Not specified

NUGGY		Posted : Sunday, 31 August 2014 1:41:25 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 20/07/2012(UTC) Posts: 267 Location: greymouth Thanks: 85 times Was thanked: 76 time(s) in 58 post(s)		Also - try to avoid having to change pumps on the motor you get. The end of the crankshaft is a specific length, diameter and thread for each different pump, it's a pain to alter this, as you have to remove the crankshaft - which means pulling the motor totally to bits, and then get the end machined to fit the new pump impeller (expensive). You might just fluke having the right set up, but having done a few I would think it unlikely. NUGGY

East-Auck-Fossicker		Posted : Wednesday, 10 September 2014 6:48:46 PM(UTC)
Rank: Gold Nugget Groups: Registered Joined: 12/06/2011(UTC) Posts: 84 Location: Auckland Thanks: 10 times Was thanked: 21 time(s) in 11 post(s)		I've got a pump you might be interested in
		WWW

goldfinger		Posted : Saturday, 25 October 2014 4:58:22 PM(UTC)
Rank: Gold Nugget Groups: Registered Joined: 6/01/2011(UTC) Posts: 37 Location: Westland Thanks: 43 times Was thanked: 19 time(s) in 16 post(s)		Keene and Proline have put many years of engineering and thought into their pumps .... to much pressure suction will not be effective as flow through the box is compromised. The Keene pump is worth every penny as it is the best compromise between flow and pressure....Get a Honda with a P180 or P350 pump. Much has been written on the balance between flow and pressure in gold suction mining.Pressure would seem at first sight to be the answer but it not. Here is the performance of the Keene 180 driven by 6.5hp Pumps a maximum of 1135 liters per minute. Capable of 180 feet of head lift. Keene 350P driven by 10hp Pumps a maximum of 1770 liters per minute. Capable of 120 feet of head lift. Edited by user Sunday, 4 January 2015 7:23:35 AM(UTC) \| Reason: Not specified

gingerbreadman		Posted : Saturday, 25 October 2014 9:09:21 PM(UTC)
Rank: Gold Ingot Groups: Registered Joined: 19/07/2010(UTC) Posts: 473 Location: south of the black stump Thanks: 34 times Was thanked: 96 time(s) in 74 post(s)		Like nuggy said go for pressure mate has one of these on his 4" when he got it didnt realize the pump was cast iron so was going to send it back as pretty heavy but the bloke told him if it was made of alloy it would blow apart so gave it a go and the suck is pretty impressive the key is having the correct jet size he played around with a few different sizes recons 13mm is the best http://www.trademe.co.nz...ps/auction-796493828.htm Cheers.