Boil Box for fine Gold on the Beach

[Bonaro]

There was a discussion about boil box tech on here but I cant find it, starting a new one.

This was posted by Zooka (remember him?) on the gold miners yahoo group. Its a write up from TrevNZ who by any account is the godfather of boil box.
Very good info on how to build and set up a correct BB with direct respect to beach mining.

 

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[arizau]

Decided to build one, tried with square bottom troughs, easy to build, but impractical for long term. Tore out the square bottom troughs, used 2in (5.2cm) PVC pipe. Advantage to round is simple... no beginning or end. To maintain a 4:3 ratio regarding the ingress/egress elevations, I made a simple design modification. Under the uphill angle iron, I inserted a 1cm thick strip of angle cut plywood. This raises the ingress water column to 4cm, while maintaining the egress height at 3cm. The blade will be parallel (28 degrees) to the sides when finished. I'll upload images when completed.

View attachment 1237179

Prototype complete, maybe -

Slurry gates to even out the flow of material and water to the underflow troughs.

View attachment 1237280


Underflow gates installed. You may have to click on the image to enlarge the Lexan gates.
I used lattice caps as guides on the right/left sides of the sluice, and lattice joints on top of the
Lexan gates to create more rigidity.

View attachment 1237281 View attachment 1237283 View attachment 1237284

Under-flow blade set to 28 degrees, which will be the sluice angle of attack

View attachment 1237287


Discharge end of sluice - Underflow blades in place. At the very bottom, there is a 1inch ledge acting as a nugget trap. As if I ever get one in North Carolina... the fine gold capitol of the USA.

View attachment 1237288

Total time for this beast to be built - 6 hours, four cups of coffee. To seal and make the sluice assembly more rigid, I'm going to apply high expansion foam to the underside of the troughs.

Nice work.

As a given, a boil box system has capture media between the boxes (example: vortex mat in the gold cube). What do you intend to use in yours and how do you intend to do cleanups?

 

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[Oregon Viking]

I wonder that also. And are those holes in the sides or covered in lexan/acrylic?



I believe that ^^^ is from here http://grumpyprospector.com/

 

[ncclaymaker]

Regarding the material used between each of the underflow channels - Polar Fleece material, like that used in heavy pajamas or sweat shirts (fleece side up) to capture the fine gold that is prevalent in NC. I'll use Velcro to attach/detach the cloth. Cleanups will be performed with a small wet/dry vac using a 12v to 110v inverter. I will not be standing in the water when operating the vacuum, as the desire to obtain a voluntary Darwin Award is not for me.

 

[johnedoe]

Regarding the material used between each of the underflow channels - Polar Fleece material, like that used in heavy pajamas or sweat shirts (fleece side up) to capture the fine gold that is prevalent in NC. I'll use Velcro to attach/detach the cloth. Cleanups will be performed with a small wet/dry vac using a 12v to 110v inverter. I will not be standing in the water when operating the vacuum, as the desire to obtain a voluntary Darwin Award is not for me.

I think you are going to have problems with the methods you have chosen to use for cleanups.
While the fleece is a good recovery medium the velcro fastening could be problematic but since you haven't shown any images of that I can't say for sure.
If you just fasten the top,bottom, and edges you will find there will be an unbelievable amount of fines that will get beneath your fleece and the bottom of the sluice.... in fact it will build to a point that it will cause the fleece to lift and bow.....
The wet dry vac thing is dubious at best, not to mention the possibility of getting cons in the filter.
You really should read Trev's treaties a little closer.
Anyway, good luck on your project.

 

[johnedoe]

I wonder that also. And are those holes in the sides or covered in lexan/acrylic?

View attachment 1238048

I believe that ^^^ is from here Grumpy Prospector Home

I think this guy has a pretty high opinion of his stuff and I think it is way over rated not to mention over priced.

 

[ncclaymaker]

I think you are going to have problems with the methods you have chosen to use for cleanups.
While the fleece is a good recovery medium the velcro fastening could be problematic but since you haven't shown any images of that I can't say for sure.
If you just fasten the top,bottom, and edges you will find there will be an unbelievable amount of fines that will get beneath your fleece and the bottom of the sluice.... in fact it will build to a point that it will cause the fleece to lift and bow.....
The wet dry vac thing is dubious at best, not to mention the possibility of getting cons in the filter.
You really should read Trev's treaties a little closer.
Anyway, good luck on your project.

The Velcro idea is dropped... particle abrasion and adhesion were a concern. Decided on a small round metal frame with a .25inch wire mess to hold down the material. This way I can easily remove the fleece and wash it in a bucket. Why on earth would I have a filter on the vacuum when suctioning up wet material? I've always used a plastic shield to keep the stuff out of the motor vanes.

 

[johnedoe]

Decided on a small round metal frame with a .25inch wire mess to hold down the material. This way I can easily remove the fleece and wash it in a bucket.

Now your on track..............Now you don't need a vacuum.

By the way. What does your signature say? ראיתי את פניו של מוחמד , זה שטן
And what does it say on your icon?...

 

[ncclaymaker]

This one is for its' intended usage... at the beach. Even though I had graded/classified(minus 1/8") all of the material going into the sluice, I determined that for non-beach use it would be difficult. The place where the author used the sluice, probably most of the material was the same uniform size. That means that the user now would have to control only the volume of fluid and material going to be processed. Unfortunately, off of the beach, the world is different... sizes galore. Classified material is a must. This variable creates a fluid variation that now requires "adjustments". Not enough feed stock in the fluid, and the volume will accelerate the water velocity in such a manner that the underflow drop channel will be scoured clean.

Afterwards, I went to YOUTUBE and viewed some of the "test" videos. They were fine, if one would wish to process material by the trowel, but certainly not in a more demanding environment... a small dredge. Some appeared to have the water flow fed by a small pump while in a laboratory environment. This type of sluice may certainly have its' place on the beach, but I suggest limited use elsewhere. A brilliant idea, but limited in scope for average use.

 

[cyberdan]

The biggest problem we face in Oregon though is the "No Power Permitted" crap though... And you definitely need a pump to operate this system.

What about a solar panel. The pump would be 12V

 

[cyberdan]

This is what I have been thinking about

Either blue wheel or blue bowl. Right now I live 25 miles from the beach in SoCA. Nothing there but metal detecting and bikinies. But I am thinking of retireing next year a mile or two from the beach where more than one river exits (and big salmon enter) in northern CA. That is real gold country. any comments on these machines?

 

[ncclaymaker]

Giving up on building stuff that works in labs, controlled environments, or by using a small hand trowel out of a bucket. Cute, but not very practical for most of us. I'll be taking delivery of a Gold Well from HM Research in Wickenburg, AZ. This appears to be the only available, practical solution to the flour or fine gold here in NC... when using a dredge. The other methods are just blowing the stuff right back from whence it came. The biggest issue is the weight, all 32 pounds of it and the hefty cost. But choices are simple, no worthwhile production piece of equipment is cheap. We'll see if it pays off or not.

The first place for testing... my farm property lies just outside of the Carolina Slate Belt. We've super fine gold here that is visible under a 20X loupe or at lower magnification on my monocular microscope. If it can separate natures gold from her sand on my property, I'll be leasing a backhoe and a trommel.

 

[KevinInColorado]

Congrats on making a choice and moving forward! With a backhoe and trommel you'll have a shot at paying off the Goldwell for sure! Post pics along the way as I'm sure many of us would like to see the Goldwell dredge build, usage and eventual scale-up to backhoe!!

Oh, and the gold, all that fine Carolina gold in your pan!!

 

[ncclaymaker]

Congrats on making a choice and moving forward! With a backhoe and trommel you'll have a shot at paying off the Goldwell for sure! Post pics along the way as I'm sure many of us would like to see the Goldwell dredge build, usage and eventual scale-up to backhoe!!

Oh, and the gold, all that fine Carolina gold in your pan!!

Optimistic... but the 106 acre area that I am the steward of, is bisected by two streams. One of which has the bedrock exposed or has very little overburden. That is the area that I plan to investigate thoroughly over a period of a week or so. The main stream is over 3/4 mile long, and the geology is weird. Quartz here and there, with mica schist all over. The veins are fairly easy to spot. Who knows what will show up besides a lot of mica.

I plan to use it as a high banker next to the stream until the water flow diminishes, then I'll mount it onto the floats. This "stream" is about 25-30 feet wide and varies in depth to 3 feet in places.

 

[KevinInColorado]

Wow, that's a RIVER by Colorado standards!

 

[Jason in Enid]

Either blue wheel or blue bowl. Right now I live 25 miles from the beach in SoCA. Nothing there but metal detecting and bikinies. But I am thinking of retireing next year a mile or two from the beach where more than one river exits (and big salmon enter) in northern CA. That is real gold country. any comments on these machines?

The blue bowl and the spiral are not production equipment. They are cleanup equipment designed to be fed with spoons.

 

[ncclaymaker]

I wonder that also. And are those holes in the sides or covered in lexan/acrylic?

View attachment 1238048

I believe that ^^^ is from here Grumpy Prospector Home

Well, I can't speak for the manufacturer, but in my humble opinion, they may exist to permit the user to visually adjust the underflow characteristics of the blades in the troughs. The question that begs an answer is however, does the user continually adjust for slurry dimensions and/or water flow, or what? Or is this spoon fed with a garden trowel?