bazooka headerbox

[TheForSaken]

First day out with my bazooka.
Ran lots of paydirt haven't had a chance to pan the cons yet. Heading back out this morning.
North saskatchewan river has only very fine mesh size gold.
It just doesn't feel right, almost as if most of the gold would just shoot out the end with the rest of the taillings.
There's nothing in the box to make any of the taillings drop before existing. I'm wondering if I should screw a piece of angle inside of the trap on the top to give the taillings an obstruction in order to stop the direct flow and give everything a chance to drop first before exiting?
Has anyone tried this mod?
I read ppl say you can't have to much water flow, my pump was not running full throttle.
What are your thoughts?
https://youtu.be/Zyz-BJHkC-w

Edit: stole the headerbox design concept from OwenT

 

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[arizau]

Nice setup!

According to what I have read and also a reply, on this forum, by a person that assembles the Bazooka, there is already a built in obstruction to do what you are proposing (look through the grizzly to see where it starts and how thick it is...only about the thickness of the sluice body itself from what I have read). I think the Bazooka people would recommend that there not be any interior modifications since they have already done extensive testing in their development process.

It looks like you are feeding with mostly sand sized material so maybe a bit slower feed rate and running the unit with less angle will help? Also it has been said, that when running sand feed, to preload the chamber with some pebbles (about the same maximum size that will fit through the grizzly) to help in capturing the smaller sized gold. If your feed already has such sized material then the unit should eventually obtain the proper pebble size mix in the box so that step probably may not be necessary but it still shouldn't hurt to start out preloaded.

Anyway, Good luck.

 

[Goldwasher]

yep there is a strip on the bottom of the grizzly deck that creates a pressure curtain that pushes material out of the flow and into the trap

 

[TheForSaken]

My gravel is classified to 1/2".
Was back out today trying to dial in the bazooka. Experimented with different flow rates and feed rates. All while my angle being almost level.
This time I had a pan catching the taillings.
Was losing loads of gold, I'm not really sure what else to do.
Looked inside the trap box and I found the strip of plastic on the top of the grizzly plate. I'm not able to get my water depth deep enough to hit the block.
https://youtu.be/_k2wEo3wqrs

 

[Goldwasher]

I watched the video. the flow has to be high enough to hit the baffle. It looks like your water isn't even touching it. The turbalence in the flow is going to prevent the fine gold from settling out. Thats a problem in all sluices.

 

[Goldwasher]

how many gpm is the pump?

 

[TheForSaken]

how many gpms is the pump?

190 GPM

 

[TheForSaken]

As I shovel my paydirt onto the slick plate I see the gold taillings behind the dirt and gravel. That tells me it settles out?

 

[arizau]

As I shovel my paydirt onto the slick plate I see the gold taillings behind the dirt and gravel. That tells me it settles out?

Can't tell from the video but do the tubes have a separate connection to the pumped water? If not then they are just draining water or seeping, through the build up of material above them (AKA a "dead bed") in the box, and not keeping the box active enough with up flow of water (eg.) you are in effect operating in a slack water state. Keeping the box active (all of the material is moving around in the box) is the only way you are going to run with efficiency. Without that the newly introduced material will settle but just to the top of the "dead bed" with little chance to penetrate so as new feed is added it quickly settles then, mostly, just gets scoured off the top of the "dead bed" and out of the box.

My suggestion....rig your water inlet so you not only overflow the slickplate but also power the tubes as much as possible. This may not completely solve your problem but I'm pretty sure you will see improvement.

Good luck.

 

[Goldwasher]

thats more than enough water. The gold you see on the slick plate is settled some may not be...and if it hits turbulance at the trap it will boil out.

Try one or two things maybe both.

Cut a 2x4 that will fit into the scoop clamp it or something so that less water can enter the scoop,and cut your tub a bit so that the main deck is lower.seal so water won't escape. Just try to keep the water level where it is but bazooka lower.

Even blocking the scoop intake a bit won't stop the trap from working. And will make it to where there is more water volume to go over your main deck.

150 gpm is not too much water for a prospector don't be scared or running that much water.

bazookas are stream sluices they work great in their design parameters...turning one into a high banker is hugely problematic....I will flat out say you'll never see a viable bolt on adapter on the market. As you have discovered it is very difficult to bring the creek to a Bazooka.

If you do not get water running through it high enough to go OVER the grizzly deck you are going to lose fine gold due to boil out.


BTW I'm the guy Arizau mentioned. I know the owner well,used to build them and I do not have a bazooka power sluice and its not for lack of trying. Once you get above a sniper in size the term portable is out the window...as you are committed to a pump the size your using. A traditional power sluice is a lot easier to run and requires less manipulation to run.

Your set up is almost there but, as you are laying in bed at night thinking about it (i know u are)...no one wants to set up a power sluice to lose gold...and it gives a false impression of the Bazookas actual efficiency...IN A CREEK

 

[TheForSaken]

Arizau, Goldwasher thank you both for the great feed back. Much appreciated

 

[mytimetoshine]

Have you ever just used the zook in normal river conditions with plenty of flow? I would suggest doing that first to give yourself an idea of how much water pressure that needs to be involved.

I Can tell you why you wernt catching gold...your trap was not fluidized properly.

 

[TheForSaken]

Have you ever just used the zook in normal river conditions with plenty of flow? I would suggest doing that first to give yourself an idea of how much water pressure that needs to be involved.

I Can tell you why you wernt catching gold...your trap was not fluidized properly.

No I haven't, the river I run doesn't have enough flow.
And I believe your right, the trap wasn't being fluidized

 

[TheForSaken]

I'm gonna steer away from this design and gather up some pvc. Gonna build a pvc manifold with a ball valve before the trap and see how this goes.
Seems to me that this design will be much easier to get my box pressurized to where it needs to be.
Any suggestions before I head out for the required parts?

 

[Timberdoodle]

I would first try adding a sluice or channel to the outflow end of the trap and make it flat and level with bottom of the trap outlet. This will create some back-pressure to the outflow and slow down the speed water is going through and leaving the trap and allow the trap to completely fill. Try adjusting its angle and water input until water is going over the grizzly. Hope this helps.

 

[KevinInColorado]

I would first try adding a sluice or channel to the outflow end of the trap and make it flat and level with bottom of the trap outlet. This will create some back-pressure to the outflow and slow down the speed water is going through and leaving the trap and allow the trap to completely fill. Try adjusting its angle and water input until water is going over the grizzly. Hope this helps.

No. Don't create back pressure against the trap.
Yes. Adjust angle and water input to have water flowing over the grizzly.
Maybe: at least run it really flat to maximize the time the fine gold has to drop into the fluid bed...that actually works pretty good too.

 

[Goldwasher]

you want the output of the trap out of the water when ever you can. Allowing proper exchange of the material. It really matters when you have lower flow.

 

[Timberdoodle]

My recommendation to add a sluice etc. to the outflow is based on the high velocity/roostertail flow out of the bazooka in the video. It is boiling out gold from the trap as he has reported in testing. Adding some level of outlet control of the flow is nothing different than what you have in a natural stream environment as tailings builds up to the bottom of the outflow and the outflow has some backpressure and water does not leave the trap at such high velocity. The Inlet design he has mimics the stream at the head. Adding something to the tail end will mimic a stream outflow as well.
It's the simplest solution I know of to fix the boil out problem.

 

[G-bone]

Maybe something like this?


A pressure box basically which pressurizes the lower chamber (much in the same way a stream flow will do)
and from there pushes water up and over the top deck with a nice smooth flow, yet consistent flow.



Just an idea that came to mind.
I'll bet the farm this has been thought of before here though.

 

[Goldwasher]

yep I made one like that it worked on a sniper. Any...and i mean ANY gaps that allow water to escape has a huge effect on the water over the deck. But, it was the closest I could get to workable.

what program are you using for those drawings thats pretty cool.