Catch tray riffles?

[AG MAN]

I'm after your thoughts of putting a couple of riffles in the catch tray of my river sluice...

Went to my local PMAV meeting last night allong with my sluice for show and tell & oppinions. Most scratched their heads a bit at first... most thought it was a good thing & would love to see it in the river.
One bloke straight away clicked & had a simmilar set up years ago in his dredge set up & recons to put a coulple of riffles in the catch tray to make it even more attractive for gold to drop itself in to.

I might give it a go - no harm in trying I think.

[Andy]

& recons to put a coulple of riffles in the catch tray to make it even more attractive for gold to drop itself in to.

Riffles in the catch tray have no influence whatsoever on whether gold will drop into it or not. All the gold, except the very finest (can just barely see it with the naked eye type gold), that initially comes off the drop will go into the catch tray. After that, if it is big enough or chunky it will stay in the tray regardless.

Remember, the tray will fill with very small sized gravel & sand as the first load of wash goes through. Any gold that falls into the tray after this will quickly make its way to the floor of the tray & gravitate to the far end.

The chunky bits will not climb the end wall unless the water is flowing through the sluice at 100 mph or the sluice is at a ridiculously steep angle. The finer gold will travel across the top of the gravel in the tray & then progressively get caught in the riffles past the tray (according to their size & weight), with the bigger finest bits at the first riffle & the smaller finest bits at the last riffle. Inevitably you do lose gold off the end of the sluice, but all the gold that doesn't get caught by this last riffle is so fine you can not see it without great magnification & is not worth worrying about.

[AG MAN]

Thanks for clearing that up Chief

[Andy]

Sept 9, 2011 12:14:53 GMT 10 AG MAN said:

Thanks for clearing that up Chief

No worries Max Marty. ;D

[Simon]

Hi Marty,

Unlike Andy, I have one riffle in my single catch tray. I like it and it works for me. In saying that I haven't tried my sluice without the riffle in the catch tray. But I stick to the formula that works.

I also have a riffle on the trailing edge of the catch tray.

Plus my new sluice will have two catch trays, with at least one of them having a riffle in it.

Cheers

Simon

[AG MAN]

Thanks Simon,
I've got the riffle on the trailing edge of the tray too. I'm heading out in the morning for a couple of hours of sluicing @ Neerim South.
I've made my current catch tray a little bit too tight a tollerance so if I put a pop rivit on the side of the box, it'll be too tight a fit I think. Might be able to bend the sides in to allow for a riffle...
I'll leave it for the moment & get a few hours of sluicing done & see how much gold gets past the current catch tray set up. If I find any gets past - I might bung in a riffle I thinks.

[Simon]

Sounds good.

Good luck............

[Simon]

Make sure you throw some shot into the sluice to see where it settles.