Sluice design Options

[Davem]

I want to build a sluice box from wood materials. I read one book that used 1 1/2 high riffles (1x2) set 1 1/2" apart. BUT I see all these designs on the internet or commercially made styles where the riffles are set maybe 6" apart. If the wider riffle spacing because expanded metal and carpet is used? I'm not sure what size riffles to use and how far aprt to set them? Thanks for any help.

[traddoerr]

Hello Davem, Many of the produced sluices have hungarin (sp) riffles with the matting under neath, such as my Keene A52 that fenixsmom talks about, this maybe why they are app 5"/6" apart as these riffles create a vortex on th down side that traps the heavys/gold.

I made a slice a few years ago in the manner your talking about, It was 12" W X 48"L X 4"D, I then put 1"X3/4" slats every 1" apart starting from 12" down from the top. This is a drop riffle method which worked pretty well till it feel apart from getting water logged so man times, I also lined the top 12" with a peace of thin sheet aluminum to give it a slick plate affect, kinda like the slick plate on many of the sluice boxs made today. With this type of sluice you won't need any type of matting, this is a lot like any of the drop riffle sluices that are made of plastic. Hope this helps you out. Best of luck!

[Davem]

I thought about welding- might be an option. I was thinking the wood would be easier. My big confusion was in a book I was reading the riffles on the wood box were only about 1 1/2" apart but when I look at the commercial styles the riffles look to be about 5-6" apart. Is the difference that the commercial style has the expanded metal and carpet? In other words if I do a traditional wood slat style then I set the riffles 1 1/2" apart with no expanded metal or carpet but if I add expanded metal and carpet then I set the riffles about 5-6" apart?
And, since I'm figuring here...What type of carpet should I use? If the sluice box is 4' long I leave the first foot open to shovel the dirt which leaves 3'. Should a single piece of carpet 3' long be put in the bottom and then a frame holding the expanded metal and riffles be placed on top and secured in place?
And the flared out mouth- how necessary is that? Normally needed?
I'll be using a shovel, screwdriver, etc. working by hand to obtain dirt to feed through the sluice box.
Thanks everybody for the help. :)