Jaron,
I don't have a Keene. Mine is a Gold Hog stream sluice.

That said, I believe you're ok leaving it running while digging more material. I have done so quite a bit and am not afraid of losing gold that way. If you have your sluice set up reasonably, then there should be no problem.

If nothing else, put a catch container under the lower end and pan the material in the catch pan to calm your worries.

Wayne

Jaron.

You should be OK leaving your sluice for that amount of time. You might consider digging a little bit and running that through the sluice and go back for more dirt. That will give the riffles more time to clear out.
If all your riffles have gravel behind them you may be loosing gold.
Another thing you might want to do is tie off your sluice to a tree or large boulder. With the snow melt going on water levels do change if you are prospecting in the western part of the country.
Winter is not over here yet. More snow tomorrow !
Scott L.

IMO, I'd stock pile the material, like two or three buckets at a time. I don't like the idea of leaving the sluice unattended. It's not anyone stealing it, but more my 15 minutes turns out to be a whole lot longer than I think. I know I'd come back at some point and find it washed down the stream because at some point I didn't anchor it well enough or like Scott said the wat3er level fluctuates and it got knocked loose. So much goes into getting me to the stream, I don't want to risk losing my concentrates. Keep in mind I've only sluiced a handful of times.

For me, I let er run
"IF" the box is set correctly, if needed, weighted down or tied off
I want to see some bare spots behind the lower riffles, not behind the first riffle, but progressively barer moving down the box
Assuming the above is true, I would expect any gold to be stuck behind a riffle
If your not comfortable with that, try as Wayne suggests, put a pan or ? to collect the tails for a bit and pan it out
Try and stay away from down stream of power houses, water flow fluctuates often, drive you nuts
After a few hundred outings, you will get the hang of it

Dont forget to stop and enjoy the surroundings

Bill

i just let mine run .ido tie it off asi have had mine come loss from water change in early summer as you have some water change at times had to go swimming for my sluice .have fun .

A bit late to the thread, but here's my two cents: If your sluice is set correctly, you shouldn't have any worries leaving it unattended for a while. I use an A52 and feel very comfortable running a couple buckets then going and digging a couple buckets and coming back. Like some of the others have said, it gives a little time for the riffles to clear out a bit more. Again, if it's set up correctly, you won't loose any gold. It's always a good idea to sink an unused pan or small tub to catch your tailings - you should be checking them about every hour anyway (if you see gold in the catch pan, you need to make whatever adjustments are necessary).

Running a sluice can be a bit challenging at times. Proper setup is the key. Take your time to ensure a nice smooth flow JUST over the tops of the riffles, keep it as level as possible to avoid buildup along one side or the other, and try to keep the tail end of the sluice out of the water to prevent "back flow" eddy's. There's a great video in the video library here... can't remember the title, but it was a video of a professional prospector/miner who gives GREAT advice on how to set up and run a sluice. Best advice I've ever heard! He also mentions that a proper feed rate means that 50% of the space between the riffles should always be clear. It's ok to have material gather in the first half of the space (directly behind the riffle), but you should see your moss or carpet in the last 50% of the space. Even with Gold Hog mats, there should be an even distribution of the material, and you should be catching all your gold in the upper part of the box (if you're seeing gold towards the tail end of the box, either slow down the flow or slow down your feed rate). Theoretically, you could let your sluice run all day and not lose a single speck.

Looking to purchase my second sluice box. I'm torn between a52 super or gold hog stream sluice. Your thoughts?

I run a gold reaper sluice all day before a cleanout. never a concern.
It's made to trap it and trap it good....

-Don