New Zealand Gold Prospecting & Metal Detecting Forums Archive

Hey
I am no expert on sluice boxes and mine is home made and different to yours but yes angle does matter
Too shallow of angle and beaches" form and clog up behind your riffles in your sluice stopping gold getting trapped in the miners moss.
Too steep of an angle and the gold washes right out of the sluice box
As for water flow if there is way to much then i am guessing gold would get washed out. But it does sink very fast. Look at how fast the water flow is in dredging sluice boxes its very fast and they still catch the gold...
So i think the most important aspect is getting that magic angle.
Basically i set mine up so i have approx a 10-15 cm drop from one end to the other (at a guess) and i put some material through it, now what i am looking for is are the beaches* that the material forms behind the riffles clearing at a good time frame e.g only takes a matter of several seconds to clear the majority of the material from behind the sluice (you can see if slowly throwing out the lighter material). If they don't clear at all then your angle is too shallow and if they don't even form then your angle is too steep.
I try and have a good amount of water flowing through my sluice i have had around 5-10 cm and upon panning the tailing's at the bottom of the sluice to check for lost gold i have not discovered any so the sluice was doing its job.
This reminds me if your worried about the angle and still cant figure it out then after sluicing for 5-10 minutes pan some of the tailing's taken from just below the end of your sluice box. Even better half bury your pan and have the end of the sluice resting on it (so the material going through the sluice also passes through the submerged pan trapping any escaped heavy's). Now pan this material and if you find gold then you know your sluice is not working efficiently.
Hope this helps

thanks guys thats really helpfull i did try panning the tailings and nothing in there plenty of black sand in box nearly nothing in tailings i ran my magnet through it as well i do have a photo of sluice in water but i keep getting an error message when i try to load it i will persevere with both trial and error i spose i havent quite got to the bottom of my ''pay dirt'' yet
so hopefully it all at the bottom lol just seems what im panning out is a lot smaller than what i saw going in cheers for info

Most of the gold is caught in the first 150mm/6" of your sluice box, quite offen when I check my riffle matting there is no gold at all. I catch plenty of black sand and catch the odd flake in my riffle mat. I have a ribbed spotter mat at the top of my sluice box and I find that most of the gold is trapped in my spotter mat.

If you tested your tailings and found no gold then I would say you have done well

I have my box usually set at a pitch of 10-15 deg, and depending of the flow, have it raised above the original bed with flat rocks, spending as much time as needed to get it just right, deepening the tail race and making wing dams with a good inch of smooth linear flowing water flowing through. Sometimes there is a good volume of water but it is sluggish and will not move the rocks, but try different ways and you will soon get the feel of when it is right. I have only a small strip of black ribbed matting at the head of the box to indicate colour, the gold will move off this after a while. Then I have green astro-turf/fake grass, the bottom third with home made riffles made from scrap....very important to have something at the end to catch anything that rolls that far and I have been surprised. Most of the yellow should be in the top third of carpet. Keep it up and happy hunting :)

You sound like a good honest chap...
So where do I send my money? Nigeria?

Edited by moderator Sunday, 14 April 2013 9:10:10 PM(UTC)  | Reason: Not specified

to continue where i started i have finished panning out my fine material and alas i am sure i did lose some gold with the amount of large flakes i saw going into my sluice box and nearly no large flakes in my fines what i was left with is less than a gram in weight bugga i will do some more research and prob some more asking on here