This is where it can start to get sticky. The water flow into the sluice is one of the variables I spoke of earlier and may also affect the previous step as far as having to build up the head end with rock to achieve the proper angle. Sometimes you have to build up this end because water flow is either not enough or too much, both will frustrate your work so take the time to get it right and your finds for the day will show it.
Here are a couple tips we use during set up that seem to work well........ We use our index finger to check depth in the riffle area, you want water flowing at or near your second knuckle.
(about 1 1/2")
When the flow into the box is square and about the right depth you will notice a "V" formation just above your top riffles, this is a good thing as you will see when material hits it.
Too much angle will cause the water to "jump" or cavitate .....
Look for a smooth sine wave (S) kind of shape flowing over the riffles. If your water is "jumping" then cut back on the angle.

Now you are ready to start feeding material into the box and dealing with another variable....Classifying.
Some folks don't classify and prefer to shovel directly into the sluice.... we feel this can overload the box and allows much of the gold to travel through while the box is in "overloaded" conditions.....remember this is your "controlled area", keep it consistent. We have also seen several setups (home made) that classify right in the slick plate area.....
This can work well for larger gold and some of the old timers used what were called "sluice forks" in the head area to keep off the large stones. Large stones setting down in your box will cause eddies in the current to both sides of the stone and clear out any material there.

One concern we face here in Colorado is the fine gold which is why we shoot for that consistency. The finer the gold, the harder it is to catch. Now if you are going to go through all that work to dig up the gold and get it into your controlled area, then you may as well try to catch it all!
If you are lucky enough to be digging where the gold is very coarse and of an average larger size.....then you will find you can be more extreme with the variables.

Another little tip......classify your material with water! Again, your "controlled environment" is only a few feet long.......when dry dirt is placed into a sluice, there is a short period of time that it takes to actually get the dirt/gold wet. This may only take a second or less but in the same time frame the dirt also traveled through 1/3-1/2 of your "controlled environment" or basically skipped right over it. This means you are expecting the bottom of the sluice to catch your gold....this is not the "optimal" conditions you were shooting for.

You may be runing placer material (rounded washed material) or bedrock digs (sharp flat material)
Depending on which you will want to classify to different sizes.
We like our Keene A52 sluiced box and to start with we use a 1/2" classifier for most placer material and we then go to 1/4" for sharp edged flat bedrocks as they won't flow through the box as well.. We classify into a bucket and then feed the sluice with a small shovel from the bucket.

If for some reason you would want to run bedrock at 1/2" classification then you will need to adjust one or both of the other variables. (angle and flow)

So.....your material is classified and the first load (shovel full) is fed in ....... feed it evenly and not too fast.......watch how the material flows into and through the box..... is the material building up on one side and not the other?
If so you either have the box tilted from side to side or your water current isn't hitting squarely, or both.
Adjust the box accordingly and then try another load.
While the material feeds into the box from the slick plate area, you will notice that the heavier pieces leave that area last and when gold is present it should slow down and/or stop on the black matting for a second or two (some specs will hold there).

The box should be able to clear the lighter material out in 15-30 seconds or so and heavier material will stay behind each riffle....heaviest at the top riffles of course. As the material flows through you will notice a "dancing" action of the material behind each riffle.....that is exactly what you want.....Gold is 19 times heavier than water and that little spot behind each riffle is the gold trapper! Old technology, that is still where it's at today.

Once you have adjusted the variables to your liking and the conditions at hand, then you are ready to just keep feeding. You can run the box until black sands have built up enough behind the riffles that the "dancing" effect is hard to see. This will vary depending on the box riffles and matting used but trust me... that's alot of buckets before that happens....keep digging!

When you are ready to do a clean up .....carefully remove the rock at the upper end while holding the sluice in it's positon at the head. Then pick up the sluice bringing the tail end up just a little before the head so as to slow the flow down as you pick up the box. We use one of those black square tubs for clean outs, but a 5 gallon bucket works just as well if you are careful. Remember...you have just worked your behind off getting that material into the sluice and your "controlled environment"..... continue that theroy with clean out and panning.....use a controlled area (tub, bucket).

Hope you find these instructions helpful and may your pan turn yellow at clean up time!

Dan Schaefer-CP
www.ColoradoProspector.com
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