would like to talk about the under current sluice

[vaquero44]

I really like this design and self classification like the top runner 2 and the cal sluice is another I like as well the gates and all the other stuff seems a little complicated for the waters I do but I'm really after is someones thought and experiments on what not to do to lose the gold different idea's on catching fine gold also thoughts on ideal sizes for smaller streams or general discussion?

 

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[arizau]

The sound of silence on this forum suggests that you may be better off trying a more proven product such as bazooka, or maybe even gold hog mats in a homemade or existing sluice body. There are many other products that are popular too and I would stick to one of the mentioned choices before I invested in an apparently unproven product. On a side note....most any of the reviewed products in other posts claim to catch almost everything down to about 100 mesh and a pretty good portion of anything smaller.

Good luck.

 

[GoldpannerDave]

I really like this design and self classification like the top runner 2 and the cal sluice is another I like as well the gates and all the other stuff seems a little complicated for the waters I do but I'm really after is someones thought and experiments on what not to do to lose the gold different idea's on catching fine gold also thoughts on ideal sizes for smaller streams or general discussion?

Off the top of my head, Russau and Goodyguy have done a lot of work building their own equipment and I know Russau recently built an over-under sluice for his dredge. I think Goodyguy built one for his dredge or highbanker or both. Try searching for their posts or PM them. C-17A (not on this forum, but has videos) has built an over-under sluice for his Keene light-weight 4" dredge to catch the fine gold of the Arkansas River. He extended the sluice by about 4 feet and caught about 22 grams of gold in about 14 hours of nozzle time.

The linked video only shows a 2 foot extension, but he felt he would do better with a longer extension. There are other videos he has made since the spring that show it. For the Arkansas, a gram and a half per hour of actual nozzle time is great. He talks about his mods in the video.

Good luck with your designs. Please share when you test it out.

 

[Timberdoodle]

I haven't been much of a fan of punchplate for in-line classification. Too much turbulence and not enough throughput. Once velocity is reached to move the oversized material off it you have lost the battle to get all the fine gold through it, although what does make it through can usually be caught at high percentages.
I think the BGT has proven that a short grizzly works even better than a much longer punchplate and flow through a grizzly is much smoother, doesn't limit the water flow and therefore the material flow through it is better.
There are always trade-offs for most equipment types and it usually revolves around throughput vs recovery. The "Holy Grail" of sluices may one day be found.

 

[vaquero44]

Hey Robert how are you sorry I wasn't around much this year had back problems in the mid summer and detected for a while but I got the fever for gold again just got a angus sluice master couldn't resist the price was a heck of a deal but I truly like the punch plate but there are so many variables now you mentioned grizzlys what if you had like 3 sizes of them going down the sluice instead of punch plate? hoping to get out tomorrow and try out the mackirk on bear river

 

[coolfinie]

The relative difficulty with perforated sheet as far as I can tell is more with the smaller holes, in that the water flow through will be quite low. This may, through reduced flow in the under layer at that section allow black sand to clog the gold catching feature moss, exp steel whatever it is, when the slurry is coming thickly. However once this potential problem is allowed for by putting material in gradually, and along the slickplate instead of in a clump in one part of it, once this is not allowed to be a problem, then the advantage of the underlayer which is reduced flow rate will work to get the sub 200 mesh gold to drop into the trap, ribbed mat, moss etc before it reaches the end of the sluice.
I wouldn't be too concerned with larger gold, that will get caught almost regardless of what you do.

 

[vaquero44]

well the gold that I find is pretty much fly poop fines and the occasional flake like some of the women I've been with in the past LOL!

 

[Timberdoodle]

Hey Robert how are you sorry I wasn't around much this year had back problems in the mid summer and detected for a while but I got the fever for gold again just got a angus sluice master couldn't resist the price was a heck of a deal but I truly like the punch plate but there are so many variables now you mentioned grizzlys what if you had like 3 sizes of them going down the sluice instead of punch plate? hoping to get out tomorrow and try out the mackirk on bear river

Hi Brandon, Sorry to hear about your back problems. I hope your feeling better now, nothing worse when you want to prospect.
There are so many variables when dealing with an over/under. I like much of the design with the TR2, long slick plate, lowered underflow etc.. I have a very similar design I have been working out off and on in the past couple of years which uses a lower undersluice also because it doesn't slow down and stop the larger material on the grizzly. Kinda freaky when I looked up the TR2 after your posting and seeing many similarities. Too bad he no longer makes them.
I would try a short piece of 1/4" spaced grizzly put in at the beginning of the punchplate. This would pull the vast majority of minus 1/4" material into the undersluice for processing. The length of the grizzly should be the same as the height of the punchplate off the lower matt. This helps set the flow rate through the sluice and keeps the riffles working and material flowing. This will also remove much of the smaller material from the slurry and result in less blinding of the smaller punchplate which follows.
With all this said, over/under's require a lot of observation and fine tuning to get the best operation. I'd be happy to take a trip out sometime before were iced out.

 

[Real de Tayopa Tropical Tramp]

Don't forget the fines by breaking the surface tension and forming a smooth Laminar flow stretch , This can be done by a phyical, very flexable material floating on the surface. Prperly done you can tame a rather fast flow to handle the coarse materiel. --dare I say nuggets ? --while collecting the bread and butter fines.