Black sand in riffles

[brendomac]

Hey Guys,

When your riffles start packing out with black sand, do you see that as the time to clean out your sluice/highbanker? Or does the gold still sink through the black sand and not skim over the top?

Im currently using a sluice, but I'm guessing the same could be said for a highbanker?

Thanks.

 

[Tathradj]

It depends on how much is in behind the riffles.
Good indicator that you are dialed in though.
When you study the area that has the sand in it,
Is it dancing around. ?

 

[Jemba]

When panning have you ever noticed how a percentage of fine gold will not penetrate through black sand. To my thinking this kind of fits your question. :Y:

 

[bazxa]

I clean out if the top 25 percent of the sluice is looking full. Full riffles provide a skid plate.

 

[brendomac]

Tath, I still don't see the black sand dancing, but i do see the other bits dancing until it fills up. That makes a lot of sense. Sorta staying me in the face I guess!

Jemba, yep i have seen that in the pan, the sand must get so packed and dense, but the gravity of the gold made me think there might be a chance.

Baz, 25% sounds like a good rule of thumb to follow. I wasn't real sure how best to approach it.

Thanks all, much appreciated.

 

[AussieChris]

So many different factors at play, the type and size of riffle itself and what you have under them, the flow of water that suits your sluice and if you have it dialed in like Tathradj suggests. Classification, are you running larger material through? the larger size/quantity of the material the more water it will need to create the fluid bed/suspended medium to let gold drop to the bottom. Miner's moss does not like stop/starts that's for sure if you have to stop, might as well do a clean out.

good article here if you like http://www.goldgold.com/the-size-of-riffles-2.html

 

[3DDevil]

Great article. Thanks AussieChris :Y:

 

[brendomac]

That is a top article. Like you mentioned, so much at play. It was interesting how he talked about the depths of the riffle compared to classification size. The other part where sometimes a bed is packed out when it looks like it isn't. Also the speed of the water...

I'll be reading that one a few times I reckon.

Thanks Aussie.

 

[Mickskin]

Good read, thanks Chris.