scoy,
Disclaimer, I do not work for CalSluice, but I'm not exactly an unbiased bystander, either. I know the owner of CalSluice, have worked with him many times, and have used the #2B for several years, so I'm pretty biased.
The video at the front of this thread, was not produced by CalSluice. The claim of increasing your production 10x is their claim, not CalSluice's, but just the fact that you can shovel directly into the box, full shovels at a time, without having to classify or dribble the material into the sluice, will increase your production, significantly.
I don't recommend splashing the material into the drop plate like shown here, but it's not because he is putting a full shovel on at once, I just don't like that he gives that little extra slam technique to get the material off the shovel. Thump the shovel onto the drop plate, OK, but with a little less vigor, you'll thank yourself at the end of the day. Let the water do the work.
WATER SETTING
The CalSluice is a fast water sluice. It was designed for production, not sampling. It is a little heavy, and it needs quite a bit of water to run correctly. It needs significantly more water than the typical open stream sluice.
The water flow in this video is not too bad, but maybe just a little high, in my opinion. I've certainly run it this fast, especially when working alone, but I usually like to run it just a little slower. I'd probably drop the flow a little, and I'd try to have a little more drop off the end. Still, if he is catching that gold he shows at the end of the video, who's to argue with that success?
My recommendations:
I like to run it best with fairly slow moving water in front of the sluice. I like to build a little still pond in front of the box and put some rocks upstream in front of the box to slow the water. Basically, I like to make the sluice a little artificial spillway for a slow water "pond" in the river. I find that putting it in the middle of the stream flow works OK, but it makes it harder to get the flow right, and you are subject to variences in flow of the river to keep your box working. You end up dinking with it throughout the day.
In still water,
The water on the entrance should just break about 1/4-1/3 the way down the mini flair bends on the front sides.
The water at the exit should just cover the rivets that hold the riffle tray latches.
There should be a drop off the back of the sluice. You do not want the back of the sluice to be submerged. ou do not want the tailings to build up at the tail of the box, either.
There should be a nice centered V in the water surface that comes together just past the first riffle, which is under the grizzly.
It good to see the slight bulge in the water flow that happens about 2/3 the way down the grizzly. This is where the bottom flow and the top flow equalize.
Adjust the angle so that you have just a small amount of material that "hesitates" at the very back of the grizzly before being washed away. Most of a full shovel of material should clear the grizzly in about 5 seconds. That's right, you should be able to process 10 shovels a minute. There isn't really drop angle formula, like inches per foot, but more of getting a feel for how the material runs through the box. I wouldn't recommend a drop of more than about 4" over the length of the box in any case.
Last, make sure the water is even and level, side to side. The best judge is that the water covers the rivets at the rear of the sluice, to the same point, center, top, just over the top, whatever, but even on both sides.
In water enters the box with some current you may need to cut back a little on the water on the front, and/or flatten the sluice a little.
The big thing is to have enough water to clean the fine material from under the grizzly, and not so much that you don't get that material just to hesitate on the grizzly before being washed away. Also, it's better to run it flatter than at too much of an angle or the riffles don't work.
If you are seeing really good gold, or lots of really fine gold, then you can reduce the water some, or flatten the sluice angle. You just MUST keep enough water in it to clear the fine material from under the grizzly, or the box doesn't work. The down side of this is you can't process material as fast, and the box may need some extra tending to clear the larger rocks from the grizzly. This cuts into your production, but if the gold is really good, it might be warranted.
As to the shoveling, it was designed to be shoveled directly into the sluice. If you place the material on the drop plate, the water does all the sorting. Most of the sorting happens before the material has a chance to get off the drop plate onto the grizzly. As the material flows down the drop plate, the gold tends to settle and be near the bottom as it drops off the drop plate. the gold then just falls through the grizzly. There is fairly quiet water running under the grizzly. Once through the grizzly, nothing disturbs it to force it down further in the sluice.
Any nuggets that can't go through the grizzly generally stop on the little drop after the drop plate, or hang up on the grizzly. I have had nuggets that fall into one of the riffles after the grizzly. They just plop off that grizzly and snuggle down after the riffles. There are three diferent riffles in the box. The ones under the grizzly are designed for slow water and fine gold, the ones after for faster water and larger gold. I do tend to keep a close watch on those last riffles before I put another shovel into the box to see if any nuggets have appeared.
PRODUCTION AND RECOVERY
On several occasions, we have run recovery tests with a #2B, with 4 feet of sluice extensions tacked on the back. Three people digging all day, nobody loafing, dumping shovel after shovel into the sluice. We estimated we moved about 8-10 yards of material (not cubic yards). That is a patch of river gravel 7x8x1.5 feet. For the bucket counting people, that's over 120 FULL to the top, 5 gal buckets of gravel. The only consideration is to allow 1 shovel to clear before the next is dropped.
There were no significant nuggets, that is, ones that wouldn't go through the grizzly, but virtually ALL the gold is under the grizzly, either caught before the first riffle or between the first and second. There is, about 3-5% of the gold that makes it past the second riffle, and precious little that makes it out from under the grizzly and is caught in the next riffle, and virtually none after the fourth (last). In one of the tests we had just under 2.2g total and a total of 3 smallish specks, the size of fine ground pepper, made it into the extension sluice, about 0.035g. I say that is pretty good recovery for a lot of meterial run.
You can never catch all the gold using gravity methods, and I know the recovery of the CalSluice is much better than 80%, but, even if it were only 80%, would you rather have 80% of 3 yards of material dug in a day, or 95% of 15 buckets? You can move a lot of material with a CalSluice. In fact, the only complaint I've ever heard (besides it being heavy) was a gentleman who took one out for a day of digging, and came back with his tail dragging, complaining that "the d___ thing is always hungry." He'd put a shovel into it, and in three seconds it was ready for the next one. He couldn't rest and have a smoke while spooning his buckets into a sluice anymore. Frankly, I don't really consider that a complaint.
Anyway, that is my $2 worth on the CalSluice. If I'm really digging, trying to get gold, and I have the water to run it, it is the box I use.
JayeLK
