ANGUS MACKIRK SLUICES - material classification

Posted: Thu Apr 07, 2011 9:15 am

from my experience with both the grub steak and au. trap sluices, i no longer will classify below 1/2" because both of my sluices handled that size with no problem at all. in fact, if i had a classifer with bigger holes, i would try that. i'm making this comment in mar/apr with water flow for this time of year. i'll also see how they both do in aug/oct when the water flow is lower and slower.

based on watching my two sluices in action and given that all of the angus mackirk sluices have pretty much the same riffle design, i think that classifying below 1/2" is a waste of effort for any of them.

am i right or wrong?

what's your experience and thoughts, base on your use of the AM sluices?

the more input, the better. it will help all of us.

Posted: Thu Apr 07, 2011 10:18 am

I dont think its more an issue if it will clear out the bigger stuff, its hard to clog a drop riffle but I would do no more than 1/4 inch just so you get good agitation and break up the material from the rocks before hand to allow the sluice to catch all the gold. IF you got bigger cobble with clay or material stuck to it that may not get all cleaned with a bigger classifier. I prefer a 4 or 8 mesh with my grubsteak and autrap and while they will cleanup with an 2 mesh pretty good, Its just a personal preference of mine for the reasons stated. Also I think the the bigger cobble could dislodge parts of your material already captured in the drop riffles and Ive seen it happen on my autrap and predator 3.

Posted: Thu Apr 07, 2011 10:31 am

the AM's are not drop riffles. look at some of astrobouncer's posts to see what a drop riffle sluice looks like.

Posted: Thu Apr 07, 2011 10:33 am

deerman wrote:

the AM's are not drop riffles. look at some of astrobouncer's posts to see what a drop riffle looks like.

ramp riffles, whatever, some angus sluices have a few drop riffles in them.

Posted: Thu Apr 07, 2011 10:40 am

there are no drop riffles in any angus mackirk sluices. some angus mackirk sluices have what they call a "boil box" at the end of the sluice. some have nugget traps also at the front.

Posted: Thu Apr 07, 2011 10:49 am

deerman wrote:

there are no drop riffles in any angus mackirk sluices. some angus mackirk sluices have what they call a "boil box".

The grub steak has a boil box on the very end and I would call em 2 drop riffles that clean out fast right at the beginning. IF thats not a drop riffle than what is it? If anything its just a wide drop riffle.

Posted: Thu Apr 07, 2011 2:20 pm

nugget traps. the au. trap has them also.

Posted: Thu Apr 07, 2011 2:21 pm

deerman wrote:

nugget traps. the au. trap has them also.

lol its a drop riffle.

Posted: Thu Apr 07, 2011 3:03 pm

I call 'em money pits. Very Happy

The gold doesn't know what there called either, it just likes 'em.

Anything over 3/4" will cause a lot more turbulance.

Posted: Thu Apr 07, 2011 3:04 pm

Cloudwalker:

Great! Very Happy

Posted: Thu Apr 07, 2011 3:28 pm

cloudwalker wrote:

I call 'em money pits. Very Happy

The gold doesn't know what there called either, it just likes 'em.

Anything over 3/4" will cause a lot more turbulance.

lmao

Posted: Thu Apr 07, 2011 9:01 pm

definition:
imao - in my arrogant opinion

Posted: Thu Apr 07, 2011 9:15 pm

deerman wrote:

definition:
imao - in my arrogant opinion

I love you too. Smile

Posted: Sat Apr 09, 2011 11:23 am

they say a picture is worth a thousand words.

Posted: Sat Apr 09, 2011 11:47 am

Hey Deerman, many times I've not even classified using the AM with serious water flow. I agree on the 1/2", you can really watch the riffles a few minutes into running and get a feel of what needs to be done. Also depends on how fast you plan on feeding it in relation to the flow. Even if you clog a few riffles you can rake your hand with the current to dislodge bigger pieces. It's hard to lose gold in the drop riffle/beveled riffle/nugget trap/money pit/boil box/ramp riffles. Very Happy

Posted: Sat Apr 09, 2011 11:52 am

digi1 wrote:

Hey Deerman, many times I've not even classified using the AM with serious water flow. I agree on the 1/2", you can really watch the riffles a few minutes into running and get a feel of what needs to be done. Also depends on how fast you plan on feeding it in relation to the flow. Even if you clog a few riffles you can rake your hand with the current to dislodge bigger pieces. It's hard to lose gold in the drop riffle/beveled riffle/nugget trap/money pit/boil box/ramp riffles. Very Happy

Only reason I spoke up was while watching my predator 3, I didnt classify my 1/2 material down any further and a heavy rock sat in one of the drop riffles or actually on the edge of the riffle and I watched it clear out the gold and everything around it since the water flow was upset right there, I could imagine that if the rock was moving slow enough that could be enough to upset the balance of the drop riffle and make it cleanout some gold with it as well. Now does this gold make it past the boiler box and nugget traps? not sure, I doubt it but I guess its possible. So not classifying on a stream sluice with good flow should clear out but personally I dont take a chance with it with anything more than 1/4 inch just for that reason.

Posted: Sat Apr 09, 2011 3:39 pm

see what you think of this.

you should use the biggest sluice you can(or have) for the current flow speed of water in the creek you are on. reason is, you process more material in the shortest period of time. let's face it, prospecting is a lot of work. why process a small amount of material when you can run twice as much, or more, with the same amount of effort.

ie., lower volume of water thru sluice - grub steak, back packer, etc.
higher volume of water - au. trap, alaskan, eureka, etc.

run the largest size material that your sluice will process efficiently.
ie., classifying takes more work than digging.

i've got a grub steak and an au. trap.
i've used both on the same creek at the same time of year and water flow.

grub steak - handled a lot more material than i thought possible. i started at 1/8" classification, then 1/4", then 1/2". even at 1/2", it had no problem processing the material. looking back, i think i probably ran too much material through it simply because i could.
my biggest problem was the water level kept rising and i had to keep raising the sluice. when i did, i lost material out of the sluice. next time, i will dump the sluice material into a bucket before i raise the sluice.

au. trap - shay is right. this is a beast. reference his comments under Product Reviews, Sluice Test Day, nov 29, 2010. my biggest problem with this sluice was classifying enough material down to 1/2" to feed this beast.
i've got to come up with a screen that dumps directly onto the flair.
will this au. trap handle bigger than 1/2"? i don't know, i dont have a bigger classifier.

i also like the look of the alaskan and the eureka for processing larger voumes of material.

on any size a m sluice, if big rocks are not being pushed through, classify down until you get to the size the sluice will handle.

is there anything i've missed? i'm still learning how to use these two sluices and i need all the help i can get.

Posted: Sat Apr 09, 2011 3:55 pm

I use the same 2 as well, I still stick with 1/4 classifier because its just easier for the sluice to cleanup. I may try a half inch which would allow me to work faster but I wouldnt try it with the grubsteak. 1 5 gall bucket of material and its time for a cleanup IMO but, cleanup is so easy its a non issue, I just do it to be on the safe side. The autrap, Ive yet to see it in a really good fast water setting but you can use it in moderate water and it does just fine there. I think in moderate water thoguh the grubsteak can handle just as much.

Posted: Sat Apr 09, 2011 5:20 pm

Hey Deerman:

Here's a idea for the Autrap.

Get you a piece of refrig shelf or bbq rack the is rectangular and bigger the the flair. Cut it into a trapezoid shape the will set down in the flair of the sluice. Either bend the back of the rack up or add a 3" fence across the back of the grizzly, to keep the larger rocks from falling back into the sluice. Add 1" tall feet to the grizzly so it sits about that high off the apron to the sluice and still under water, that way the water will wash the smalls into the sluice leaving the larger rocks on top. Then take your shovel as needed and wash the larger rocks to rinse any small dirt and gold thats clinging to the rock.

Then all you need to do is pick the grizzly out of the sluice when ever their are a lot of rocks on it, dump and replace the grizzly.

Hope you find a lot of the yella stuff.

Dickb

Posted: Sat Apr 09, 2011 5:42 pm

cloudwalker wrote:

I call 'em money pits. Very Happy

The gold doesn't know what there called either, it just likes 'em.

Anything over 3/4" will cause a lot more turbulance.

i stand semi corrected, it's drop ramp riffles, because the top of the ramp riffles are not higher than the floor of the sluice.

Posted: Sat Apr 09, 2011 10:46 pm

I do 1/4" for Explorer...

if its really really stick thick clay, I like using a 1/8th sometimes...to break up all that clay real good and most of the gold in NC will go through a 1/8th no problem.

I just use a 1/4" all the time, I got a 1/8th now and figure I can run more material using it.(depending on water flow, etc)

Posted: Fri Apr 15, 2011 5:40 pm

This comes from a someone who has OCD. I like to think of it as Attention to Details." My friends will tell you that I'm just anal.

I always clssify at least one size smaller than the manufacture reccomends. Gold Cube says to classify to #8, I usually classify to #12. (I can see pickers and flakes to size 12 in my pan easily.)

Dredger Joined: 22 May 2010 Posts: 605

With the advent of drop riffles, ramp riffles, double flared sluices, boiler boxes, hungarian riffles, dredge riffles and expanded metal riffles, a topic comes up enough to warrant at least an informed conversation among the proponents.

That being how small to classify, if at all.

In my opinion, tiny gold cannot compete with larger gangue in any environment needing water and gravity to recover values. Particularly when these large rocks are tumbling down the sluice causing turbulence while the gold is trying to find a low pressure area to land.

Here's my reasoning: If two similarly sized particles are are in a sluice bed, and one of them is gold, then the gold will always lag behind, and can easily find a low pressure area. But if a gold piece of a given weight is in the sluice with a rock of the same WEIGHT, and perhaps a bigger size, the rock will have more displacement, therefore more ability to displace the gold.

Keep classifying guys!

Sam

Posted: Fri Apr 15, 2011 7:06 pm

SamBurgin wrote:

With the advent of drop riffles, ramp riffles, double flared sluices, boiler boxes, hungarian riffles, dredge riffles and expanded metal riffles, a topic comes up enough to warrant at least an informed conversation among the proponents.

That being how small to classify, if at all.

In my opinion, tiny gold cannot compete with larger gangue in any environment needing water and gravity to recover values. Particularly when these large rocks are tumbling down the sluice causing turbulence while the gold is trying to find a low pressure area to land.

Here's my reasoning: If two similarly sized particles are are in a sluice bed, and one of them is gold, then the gold will always lag behind, and can easily find a low pressure area. But if a gold piece of a given weight is in the sluice with a rock of the same WEIGHT, and perhaps a bigger size, the rock will have more displacement, therefore more ability to displace the gold.

Keep classifying guys!

Sam

Exactly my thoughts sam.

Posted: Fri Apr 15, 2011 7:18 pm

Yeah, I agree on that. Especially that clay....that stuff is a bitch to classify and work but it pays off in the end! Smile

I will never use any other kind of sluice other than an angus again...unless it is improved or better than those!

the explorer is just top notch...it will catch stuff to -200! probably smaller