Building Your Own Sluice Box
Making your own sluice box for gold prospecting is fun, rewarding and educational. The best part is there is not a lot to making one work and you can build one for all days runs or a small one just for cleanups or both. You may want to consider looking at some of the ready made sluice boxes to get a good idea on how they are designed before you begin.
The sluice box is far from rocket science and is just a simple way to use water and gravity separation to recover gold. The sluice box concept has been around for thousands of years and they have been made from wood with carved riffles, modern steel and aluminum designs, plastics, and even the earth itself where prospectors carved out riffles in washes and streams during the dry season hoping to catch some flood gold. Personally I would avoid wood at all costs for long term usage. Why? Think about your experiences with wood and water, what happens? Wood swells, becomes heavy, dries and cracks.
When it comes down to design for clean ups, a small sluice can be from a foot long to several feet long and from a few inches wide to about six inches wide. For all days runs I recommend about three to six feet in length and ten to fourteen inches in width. For matting miners moss is an old favorite for sluice boxes for fine gold recovery and also don't forget the ribbed matting. Ace hardware sells ribbed matting by the foot, its black and thin. Many times I've used only the ribbed matting in my sluices. One of the places people seem to get hung up on with sluice construction is riffle angle. All we need to do make the riffles at a 45 degree angle, that's it. The best designs have removable riffles, this will help with clean up. You will want to layer your sluice box as such, matting, screen (1/4 to 1/2 inch is recommended) and the riffles should be held tightly down on top. The top part of the sluice should not have any riffles and be about a foot to a foot and a half long. This is where you will shovel your material in, traditionally, this are is "Y" shaped but it does not need to be. Remember with a good design most of your gold with stay in the top thirty percent of your riffles.
This brings us to our next question, running slope grade. Remember each area is different but a good rule of thumb is about one to two inches of grade per feet. Experiment to get the best recovery. Remember the material should flow through your sluice quickly, evenly and the only material that remains left behind should be the heavies, gold, black sand, and other heavy minerals. If the riffles look to be packed with black sands it is a good bet the sluice is working properly. With aluminum a quick trip to Home Depot should be enough to get your creativity going, questions answered on tools, and the best part is that aluminum is easy to work with.
The pictures at top can be enlarged by clicking on them. From left to right: That's me with a mini sluice filming in 2003 near Cleator, AZ. Old friend BBQ Bob sluicing about 1999. Myself and BBQ Bob sluicing deep in the Bradshaw Mountains about 1999. It would be great to see any projects you make. Please feel free to join our online forum and share your thoughts and experiences.