Friday, April 11, 2014

Working Low-Water Bedrock (Part 3)

 (You can see the high-water level marks on these boulders that have been left high and dry along the bank of this stream.)

In this post and the next, I'll be talking about a few pieces of small-scale mining equipment and various hand tools you may want to consider if you're going to be involved in working low-water bedrock. Remember, extreme low-water conditions like those currently affecting California and other parts of the western United States offer exceptional gold recovery possibilities for those in the know.

Sluice Box: More than any other single piece of mining equipment, the humble sluice box offers portability, ease of set up, efficiency, and a gold-grabbing capacity that, dollar-for-dollar, remains unmatched over the years. Under low-water bedrock conditions a trusty old sluice box may be your best bet for running the material you pull from cracks and crevices, behind and below obstructions, and in processing bedrock overburden. In experienced hands, a properly set up and configured sluice will process significantly more gold-bearing material faster than a gold pan, even if that pan is in experienced hands.

Here's a sluice box tip for you to consider. If you're working an area of low-water bedrock where there's not enough water flow to wash gold-bearing material through your box,
1) Construct a jury-rigged stand or support of rocks, wood, or tailings that the hopper end of the box can rest upon freely, but with a measure of stability as well.
2) Adjust the height of the stand so that the pitch or angle of the box is not too steep or too slight. Just as in operating a sluice box in running water, you want the gold-bearing material moving down the box freely, not clogging it (too low an angle) or being flushed out the other end all at once (too steep an angle).
3) Place a full-sized gold pan underneath the lower end of the sluice box.
4) Plop your rear end down on an upturned 5-gallon bucket next to your "box-on-a-stand" and grab your material bucket.
 (One of Keene Engineering's newer sluice box versions. I believe this one breaks down into three parts or sections.)
5) Using your hands, a small shovel, or a garden trowel, place a small amount of gold-bearing material in the hopper end of the box and flush the same using any suitable water receptacle.
6) Pour the water slowly and as you do shake or "rock" the box gently from side-to-side as the material is flushed down the sluice and out the other end.
7) Repeat this process.
Yep, you're absolutely right. You're adapting your sluice to function as another old gold mining standby, the rocker box.

Portability, Portability

No, your sluice box won't catch gold at peak efficiency this way like it would if properly set up in good water flow. However, despite the "clunkier" aspects of this adaptation, it works quite well. You'll lose very little, if any, gold if you take things slow and are careful. Using a gold pan as a catchment device at the lower end of the box also helps.

(This nugget was detected electronically first, then dug out of a bedrock crevice. Photo courtesy The New 49ers.)

I've used this technique many times over the course of three and a half decades as a small-scale gold prospector and miner. "Why not just use a rocker?" you ask. Well, for starters my sluice box is easier to carry and more portable than the hand-made rocker I used occasionally in my mining forays. This point gets driven home even further if you're humping the distant boonies to get away from the crowds. Many new sluice boxes can be folded up and stuffed into a backpack or 5-gallon bucket. Try doing that sometime with a full-size rocker box. I rest my case.

Anyhoo, thought I'd throw this idea out there since there is a strong likelihood some of you will be working low-water bedrock conditions with limited water available for processing gold-bearing material.

Best of luck to one and all.

(c) Jim Rocha (J.R.) 2014

Questions? E-mail me at jr872vt90@yahoo.com

2 comments:

  1. JR, Last summer when the water got low, I did a similar thing as you describe. I took the flare end off my sluice, cut 2/3 of the bottom of a 5 gallon bucket off,and bolted it in place of the flare.I made a hopper of sorts. It worked good with a classifier screen on top of the bucket. Like you said, you can't run the water real fast,and you don't go through as much gravel, but much faster than a pan alone. Gary

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  2. It's like the old adage Gary..."Whatever works, works!" Best, J.R.

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