bazooka filling up too fast?

[steveh2112]

i have a 30" bazooka sniper. i can barely get 2x 14"full pans of gravel in there before its full in the collection area.

i think i have decent water flow. its not a rushing torrent but it is running at about walking pace i'd say. i have the the top of the sluice just a little under water and sloping down about 2-3"

am i doing something wrong, because right now, is seems like its just easier to go straight into the pan than spending time sluicing then panning

thx

 

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[arizau]

If the material is loose (you can stick your finger down through the loose gravel while running) then it is working. The object is not to clear most of the material but to have it loose so the newly introduced and heaviest material, gold, etc., can sink through the active bed. When not feeding, some material flushes but the remainder just seeks a level usually just below the exit port height. If it idles for a long time the level will probably be lower than the lip but the box will still probably be half or more full below the lip.

 

[steveh2112]

so i can keep piling material in then without worrying that the gold is just washing out?

 

[arizau]

Many run the equivalent of several 5 gal. buckets and some just run all day or until they are tired. If you notice that the box is mostly full of black sands do a cleanup. There is a lot of discussion about this if you check other bazooka threads on this forum.

 

[KevinInColorado]

I have yet to find a place where I had to empty the Bazooka ...more like I needed a break from shoveling like mad and my excuse was to empty it to see how I was doing!

Arizau has it exactly right!

 

[Goldwasher]

as long as the material feels loose and is just under the end plate...(exit end)....your fine I run my prospector all day with out dumping the trap. If you can feel the top of the tubes your fine.

 

[GoldpannerDave]

so i can keep piling material in then without worrying that the gold is just washing out?

Short answer, yes.

 

[The Gilded Lens]

That's how they work. It's an exchange. Just keep going... and going.... and going... unless the thing fills up with ONLY black sand, you're fine.

 

[KevinInColorado]

That's how they work. It's an exchange. Just keep going... and going.... and going... unless the thing fills up with ONLY black sand, you're fine.

I think she means "until it fills up with only GOLD!" LoL

 

[Aufisher]

Keep on digging!

 

[Goldwasher]

I think she means "until it fills up with only GOLD!" LoL

yea, my complaint is that the trap doesn't fill fast enough

 

[The Gilded Lens]

I think she means "until it fills up with only GOLD!" LoL

That too, Kevin!

 

[goldenmojo]

Steve I locked my supermini up recently due to super low flow and no way to get an elevation drop on it. The material I was using was small all within a certain size and I have a habit of always overloading it. If I had better just a little better flow and some drop it would have handled the material easily as it actually was working somewhat but slowly and I could pan faster than constantly fiddling with it to get it to process. The trap will always load up to a certain level and exchange junk material for shiny material. If it backs up through the grill and up onto the plate and you have nothing exiting the slot after you have just sent material down the plate you are in a lockup mode but that condition is extremely rare.

 

[NorCalPilot]

I locked-up my prospector twice today. I increased the drop, stayed with the same flow, and it ended up just fine.

 

[INDEAD]

I think the Bazooka is by far the best sluice out there, however I have had lock up happen several times.
I would like to know how many users set them up on dams, or use them in the stream like a matted sluice.(which is what I do)
I always think I have good flow till the catch fills, then it locks up, when I try to increase the angle, it drops the catch below the surface, and the low pressure also locks it up.
It doesn't help that at least 1/4 of a shovel full is black sands!

 

[KevinInColorado]

I've run it both ways and can confirm that like any sluice, having the bottom end under water can cause material to backup or lockup. This won't happen when the waterway is moving fast of course but in slower moving water it can be tough to set up a sluice of any sort unless you have enough slope in e stream to have the bottom end out of the water.

One tip to minimize lockup when the whole sluice is submerged like this:

Make sure the sluice is exactly aligned with the natural direction of water flow at that spot in the stream. This pic is from my outing on the upper Delores River near Rico just last week. I had it running well as you see here, then did a cleanout and when I put the sluice back in the water it wasn't aligned to the stream flow and BOOM I had a lockup!

A lot of times if you get a lockup you can correct it just by moving the sluice around from side to side or adding/ removing slope right in that moment...no need to empty the sluice first! You will know when the lockup releases because the trap will start ejecting material again like it should

 

[INDEAD]

Thanks Kevin,
Good information.

 

[arizau]

INDEAD: I think a heavy dose of black sand feed is the bane of bazooka sluices especially when it is of sizes of 50 mesh and smaller. At those sizes there is little to no gap between the particles when they settle so that they just form a bed beneath and around the tubes and become almost impenetrable leading to further buildup and lockup. Some on this forum have said that preloading the trap with larger stones helps to prevent such a compaction. I think that that is true but, IMO, it is only just a temporary fix where large doses of heavy black sand are in the feed material and that frequent cleanouts are still necessary. One thing that might help with this type of feed is to slow down the feed rate and let the box sort itself out between shovels. Check the box periodically with your finger to see if the box is still active and if not empty it.

Good luck.

 

[KevinInColorado]

I think a heavy dose of black sand feed is the bane of bazooka sluices especially when it is of sizes of 50 mesh and smaller. At those sizes there is little to no gap between the particles when they settle so that they just form a bed beneath and around the tubes and become almost impenetrable. Some on this forum have said that preloading the trap with larger stones helps to prevent compaction. I think that that is true but, IMO, it is only just a temporary fix where large doses of heavy black is in the feed material and that frequent cleanouts are still necessary. One thing that might help with this type of feed is to slow down the feed rate and let the box sort itself out between shovels. Check the box periodically with your finger to see if the box is still active and if not empty it.

Good luck.

Not really an issue from what I've seen. I have extremely high levels of iron sand in some spots here and the Bazooka will spit it out happily while keeping the gold.

 

[arizau]

Not really an issue from what I've seen. I have extremely high levels of iron sand in some spots here and the Bazooka will spit it out happily while keeping the gold.

Note that INDEAD stated that at least a 1/4 of the feed was heavy black sand and that is what I meant when I said "a heavy dose". The total weight representation of the black sands may be well over 25 percent of the total that enters the box with each shovel full. Much of that will immediately drop some or a lot before it is much influenced by the up currents generated by the influx of water through the tubes. There are many dead zones between the numerous up currents through which material drops then may be raised up and out when they drift into or are stirred by nearby currents. Other material simply settles with little to no extra influence other than stirring. I don't doubt that you encounter a lot of black sand but, in that proportion of feed material? And, is it mostly minus 50 mesh as is the basis of my theory? It is easy to imagine that your final con proportions may come close to that though.

By the way, gold that cannot penetrate should be retained on top of the bed if one forms as long as the bed is lower than the exit.