Astrobouncer
Hero Member
- Jun 21, 2009
- 823
- 344
I posted this in a more local gold prospecting forum I use, but thought I would re-post it here since this is a good DIY project, easy to make, and cost effective.
So the new big thing (besides that newfangled sidewinder sluice) seems to be the drop riffle design. Some sluices that use this design: Le Trap Sluice, California sluice box, and the Angus Mackirk Sluices use a variation on this as well. I'm sure there's more but that's all I could think of off the top of my head.
I ran out of V matting and carpeting from my last couple sluices but it just so happened that I still had a three foot piece of hardwood that would serve as a decent base board for a drop riffle design.
The pros of this design:
You don't have to classify supposedly cause the small riffles don't let big rocks drop in them.
Less water flow is needed because the water doesn't have to flow over riffles and other obstructions.
Looks like its capable of some very fine gold recovery in the shallow riffles.
Easy to clean up, just tilt it sideways and pour water in.
Not as much black sand to go through.
The cons:
Might have to cleanup sooner then a conventional sluice due to less gold holding area. This is offset by how easy it is to do a cleanup.
No inspection mat to see if your in the pay streak. However if you know an area has decent gold, I guess this doesn't matter so much.
Not as much black sand to go through, which means you might recover less gold/black sand mix.
I started with a 1/16 inch groove for fine recovery and gradually increased the depth till it goes to a full 1/4 inch depth on the back riffles. I also gradually made each second riffle wider, while keeping some 1/16 inch grooves for fine recovery between them.
The board I had wasn't perfect, it had scratches and blemishes on it from using it to bear down on, but its good enough for this project.
Here's the grooves from the side.
Here it is with all the grooves cut in it ready to start waterproofing.
Here's after the first urethane coating.
Another pic of it drying.
Since all I had to do was cut some grooves in the board to make a drop riffle sluice, this is an easy project and cost effective. I already had polyurethane and gutter sealer to make the sluice waterproof and seal the crevices between the boards.
The dimensions are 9 1/2 inch by 33 inches, which is just wide enough once I put the sides on it, to use it in a 5 gallon bucket for a cleanup. And its short enough to be back-packable.
Total cost for the sluice: 7.03$ for the can of Truck Bed Liner textured paint I used on it. Might put a couple reinforcement bars on it once the paint (fully) drys, a couple places for rocks to hold it down in the river.
Oh and I tested it already yesterday (when it was unpainted) on some of my cons from Saturday, and gold didn't make it past the first riffle. I used a couple different drop angles for the preliminary test, but I cant wait to try it out on the river.
Does anyone know the proper angle to setup these drop riffle sluices? I figure its similar to the 12 inch length = 1 inch drop that regular sluices use?
Here's the drop riffle sluice pictures.
Here it is next to some of my other homemade sluices.
[youtube=425,350]<object width="480" height="385"><param name="movie" value=" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>[/youtube]
So the new big thing (besides that newfangled sidewinder sluice) seems to be the drop riffle design. Some sluices that use this design: Le Trap Sluice, California sluice box, and the Angus Mackirk Sluices use a variation on this as well. I'm sure there's more but that's all I could think of off the top of my head.
I ran out of V matting and carpeting from my last couple sluices but it just so happened that I still had a three foot piece of hardwood that would serve as a decent base board for a drop riffle design.
The pros of this design:
You don't have to classify supposedly cause the small riffles don't let big rocks drop in them.
Less water flow is needed because the water doesn't have to flow over riffles and other obstructions.
Looks like its capable of some very fine gold recovery in the shallow riffles.
Easy to clean up, just tilt it sideways and pour water in.
Not as much black sand to go through.
The cons:
Might have to cleanup sooner then a conventional sluice due to less gold holding area. This is offset by how easy it is to do a cleanup.
No inspection mat to see if your in the pay streak. However if you know an area has decent gold, I guess this doesn't matter so much.
Not as much black sand to go through, which means you might recover less gold/black sand mix.
I started with a 1/16 inch groove for fine recovery and gradually increased the depth till it goes to a full 1/4 inch depth on the back riffles. I also gradually made each second riffle wider, while keeping some 1/16 inch grooves for fine recovery between them.
The board I had wasn't perfect, it had scratches and blemishes on it from using it to bear down on, but its good enough for this project.
Here's the grooves from the side.
Here it is with all the grooves cut in it ready to start waterproofing.
Here's after the first urethane coating.
Another pic of it drying.
Since all I had to do was cut some grooves in the board to make a drop riffle sluice, this is an easy project and cost effective. I already had polyurethane and gutter sealer to make the sluice waterproof and seal the crevices between the boards.
The dimensions are 9 1/2 inch by 33 inches, which is just wide enough once I put the sides on it, to use it in a 5 gallon bucket for a cleanup. And its short enough to be back-packable.
Total cost for the sluice: 7.03$ for the can of Truck Bed Liner textured paint I used on it. Might put a couple reinforcement bars on it once the paint (fully) drys, a couple places for rocks to hold it down in the river.
Oh and I tested it already yesterday (when it was unpainted) on some of my cons from Saturday, and gold didn't make it past the first riffle. I used a couple different drop angles for the preliminary test, but I cant wait to try it out on the river.
Does anyone know the proper angle to setup these drop riffle sluices? I figure its similar to the 12 inch length = 1 inch drop that regular sluices use?
Here's the drop riffle sluice pictures.
Here it is next to some of my other homemade sluices.
[youtube=425,350]<object width="480" height="385"><param name="movie" value=" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>[/youtube]
??
