How to set the correct angle on you river sluice

How to set the correct angle on you river sluice PDF file.
http://www.blackhillsprospectingclub.com/files/how_to/sluice_set_angle.pdf

The very first line of this "How do I set the angle" says it all ! every stream ,creek,river is different in some way and it usually is in the heavy sands that lie within ! So getting to know your creek is vital to getting good returns from it .


Well, now, A consise and accurate explanation!

I, myself, use about the same system.

Once I set up a stream sluice as level from side to side (by looking at the depth of water on each side) I "eye ball" the drop at about 1:12. For us here in the US that's about 1 inch per foot. http://www.convert-me.com/en/convert/length

When that is about right with 1 - 2" (2.5 - 5 cm) of water coming into the top of the box, I find a 3/4" rounded pebble (2 cm) and drop it into the top of the box. 5-8 seconds later (no conversion, eh! ) that pebble should have rolled, tumbled and skipped through the box. There is my "Starting Point" for the final set-up.

From there I shovel a little gravel into the top of the box and watch the results. If the riffles work to process the slurry and pass the lighter material, while maintaining a little 'working area' between the riffles I'm set! If the inner space between the riffles packs with material (or washes out too much) I need to do one, two, or three interchangable things.

Either adjust the speed of the water entering the box (not the best since it's a bit unstable), adjust the water volume (flow) entering the box or adjust the drop of the box. Adjusting any 1, 2 or 3 of those factors will allow you to 'tune' the box for your location.

One last "thing" - gravel size. Gold weighs about 4 times what the other heavy stream materials weigh (here in North America). A flyspeck of Gold weighs 4 times what a flyspeck of gravel weighs. A flyspeck of Gold weighs about what a 4 times larger chunk of gravel weighs. Any yet-larger gravel is heavier in the pan or sluice than our fly speck Gold. Classifying gravel to be a bit less than 4 times the size of the medium size Gold you anticipate finding means that the Gold will not be 'bullied' by much larger gravel chunks (especially for panning).

Having said all that, slurry in the riffles of a sluice are in a vortex state (like the fameous Quicksand in the old movies). That means that in a well tuned sluice box the flyspeck Gold can DEFY (I love that word) the larger slurry sized material, drop and remain behind (in the riffles) from that larger sized slurry.

Such is the 'magic' of riffles.

Man you have a way of explaining things!! Brilliant Im much better showing hands on than explaining in the written word but you have enthused me to learn from the way you put things KAEOJ !! again well done any newbie to wet gold mining should cut and paste this explanation into a folder for themselves and read over many times!!

Murachu wrote:Man you have a way of explaining things!! Brilliant Im much better showing hands on than explaining in the written word but you have enthused me to learn from the way you put things KAEOJ !! again well done any newbie to wet gold mining should cut and paste this explanation into a folder for themselves and read over many times!!

What more could i say Brilliant KA.