Doubts about sluice box!

[Von Mises]

Hello everyone, I am new here, and new in the theme of gold capture,
I've been studying a possibility of building my own sluice box,
but I still have a doubt about the space between riffles,
I saw some people saying are a correct distance are 2 inches, but
I thought that this leaves very close, another doubt and about how
make a measurement of the angle of the upper lip of the riffle, they said 15 degrees
From the base, I do not understand how it works, can anyone help me?


Sorry for the bad English.

 

[oidium45]

2 inches seems to be the standard from what I have read while debating on designing a sluice. However, I think it depends on far more variables and I have seen quite a few vids where most of the gold was caught in the first section of V matting or expanded metal so that may not be an entirely bad idea.

 

[N-Lionberger]

The big riffles that came with my dredge box were two inches apart but it is a 4" dredge, much more water flow and big rocks rolling through, that aside it had really bad fine recovery, cut some out and replaced with 4# expanded works better. Did the same with my Keene A52 cut out the riffles and welded in some 4# expanded. Works great.

 

[goldhog]

When it comes to a stream sluice... the PROPORTIONAL FORCE video is a VERY important one to watch.
Also, understanding what happens at DIFFERENT ZONES in a stream sluice is VERY important.
i.e. The flow at the end of a sluice box slows down due to BACK PRESSURE. Not many people realize this until you point it out.
If you'll notice below.... low flow and regular flow mats... the ENDS on both have no "riffles" of any type.
This allows rocks to keep rolling and account for lessened exchange.
Doc



Also...... go to 9:31 in this video.

 

[Bonaro]

A plain sluice with common carpet will catch 95% of the gold if operated properly. You can spend a great deal of time and money on riffle design and fancy mats trying to get at most a 2 or 3% increase in efficiency. Unless you are running a large commercial operation, the percentage of loss in a common sluice is irrelevant.
If you cant buy an old sluice then just copy an existing design.
Keep it simple and shovel on