Most gold prospectors start out using a gold pan, but quickly realize that they will be able to process a lot more material if they use a sluice box. A sluice box helps you process more materials quickly than when you use pans alone. And they are relatively inexpensive so you won’t break the bank with the upgrade.
If you want to recover more gold from your prospecting expeditions then you should consider using sluice boxes. There are quite a number of sluice boxes that you can buy online, but you can also easily make your own sluice boxes from materials around you. Plus there is a great satisfaction in finding gold in a sluice box that you built yourself, just like the old-timers use to do!
To build your own sluice box follow these simple steps:
1) Choose your Materials
You can build your own sluice box from a number of materials. The most easily available material that has also been used over for the longest period through history is wood.
Using wood has one advantage in the fact that it is easily available and you can construct your sluice box on site. This may not be a concern for some prospectors, but many miners all around the world have limited resources and therefore must make their own mining equipment. Wood is the most common material.
Of course the major problem with wood are that it becomes heavy if you are a serious gold prospector and you want to move around with your sluice box looking for new places to prospect for gold.
If it is available to you, I would choose to use aluminum which is lightweight and more portable than wood. It is also strong and does not rust. Most of the commercial sluices on the market today are built out of aluminum.
The other material that is now being used for certain types of sluice boxes is plastic. Some of the plastic sluice boxes on the market actually work very well. However, making a sluice out of plastic requires specialized tools that most people probably don’t have access to, so for the average prospector interested in building their own sluice box, aluminum is probably the best choice if available.
2) Plan and Design your Sluice Box
A sluice box is simply a long narrow box fitted with a number of obstructions referred to as riffles. When placed in a stream of running water the gold bearing dirt from the stream is fed into the sluice box where gold particles are caught by the riffles while the lighter dirt is washed away.
Surprisingly, the general design of sluice boxes for gold mining has not changed much over the past several centuries. There have certainly been some improvements that have been incorporated into sluice boxes over the years though, and it would be a good idea to incorporate these feature into any sluice that you are building.
When designing your own sluice box it is important that you have a look at a number of commercially built sluice boxes so as to have an idea of what you want to build. You may also get a number of free design plans online that will give you exact measurements to use that you can modify to suit your needs.
If you are looking for a simple hand fed sluice box then it does not need to be particularly large. Old sluice boxes were often longer than 5 feet long with walls that exceeded 12 inches in height. It really isn’t necessary to make a sluice box this large. If it is designed properly you should be capturing most placer gold within the first few riffles of the sluice box, and certainly no more than 3 feet long.
A sluice that is approximately 3 feet long, 12” wide, and 6” tall is a good general size that will work for nearly all situations. This will make you a perfect sluice box that is both portable and easy to use in the smallest of streams.
3) Build the Frame
If you are using wood you will need if you are using wood you will need Gorilla Glue of some other powerful adhesive along with nails to put together your box. A solid construction will help ensure that the box does not get warped over time as it will be constantly exposed to water and sunlight.
Make sure your measurements are accurate and the cuts are straight so everything fits snuggly together. Use quality wood, not plywood or cheap, warped wood. This will deteriorate quickly over time.
If you chose aluminum then screws and rivets will take the place of nails and glue. Building an aluminum sluice will require a few more specialized tools than a wood sluice will, but the end result will likely be of better quality, and much more lightweight and portable.
4) Choose the Riffles
Most sluice boxes employ obstruction blocks referred to as riffles to block the free stream of rock and sand from being washed out of the sluice box. The riffles work by creating low-pressure pockets where gold from the dirt being washed in the sluice box is collected.
Gold is about 19 times heavier than pure water and roughly 16.5 times heavier than same size rock (quartz) and this makes it easy for gravity separation to take place. Sluicing for gold can be quite challenging given the difference size of rocks and gravel in rivers and streams and the actual of size of gold particles in the same rivers and streams. The heaviness of a large stone or rock is often the same to that of a little chunk or bit of gold. This is made worse by the fact that most of the gold we recoup from streams is often small flakes, little chunks or even flour gold.
One approach to take care of this issue is to classify our material before attempting to separate it. This works down to about 1/8 of an inch and any step further may affect our tools. Using riffles is the best trick to separate gold particles from sand gravel and other forms of dirt found on river beds.
Riffles are an important part of any sluice box. They are where the heavy gold particles are capture and retained when the gold bearing materials are being washed. For a simple design, you will want your riffles to be removable so that your sluice box can easily be cleaned when you are through with prospecting. To capture more gold the design of your riffles should be able to cause turbulence in the flowing water so that the fine gold particles can drop out of the dirt being washed.
The best type of riffles into your sluice box will depend on the size of your sluice. Generally the use of aluminum or steel plates that you attach to the base of your box at 45 degrees using nuts and bolt that you can easily unscrew when you want to wash your sluice box.
The simplest and most common material to use is expanded metal. This will be added over top of the matting material to create a perfect location of gold to settle and get trapped. The advantage of expanded metal is that it is all attached as one piece, so you can remove it with just a few bolts during final cleanup.
5) Adding the Matting and Mesh
You should also be adding some form of material below the riffles to help capture the gold. You can use a piece of the miner’s moss or a piece of home carpeting material for this.
The sluice boxes used during the early days were made with riffles only. They capture a great deal of gold, but quite a significant portion of the finer gold often wash directly through them because they simply didn’t have access to matting materials in most situations.
With the diminishing of rich gold deposits along rivers, these gold prospectors, in the end, learned that lining bottoms of their reliable sluice boxes rough materials could help capture a greater amount of the fine gold. A few materials regularly used for matting materials are indoor-outside carpeting, miner’s moss, and specialized ribbed matting among others.
Miner’s moss is specifically made for this job. Home carpeting is a cheaper option, but gold recovery will generally be less, and for the moderate cost of miner’s moss it is recommended that you use it for the best recovery.
In recent years, specialized rubber matting has become a favorite of many prospectors as they are finding that they get even better recovery by using this material.
6) Testing the Sluice Box
Once you’ve constructed the box, added some sort of matting material, and have riffles in the box, you’ve basically got a sluice box that is ready to use. But you may want to refine it further especially if you are going to use it for different gold prospecting sites.
Once you are sure that your sluice box is ready for you use you should start by testing it. This is the only way to know if the sluice box will help you recover more gold from the gravel or not.
The first test should be done using crushed gold ore or some gold dust. Use a predetermined amount in a controlled setting so that you will know exactly what your recovery rates are, and you will be able to recover any lost gold that happens to go through the sluice box.
Set up your sluice box ready for use as you would do when actively prospecting for gold in the field. Feed the material into the sluice and run the water through the sluice as you normally would. Once you’ve done this, go through the dirt that just passed through your sluice box to see if the sluice box caught all the gold. This is an important test that will let you know if your sluice box is effective or not.
Even the very best designs will lose some gold, but if you find that you are recovering a high percentage of your fine gold then it is quite effective. You should be shooting for a recovery rate above 90% if possible.
After you’ve done some home testing and you feel that you are getting good recovery from your design, you need to conduct a real-world test for your sluice box to see how well it performs. It’s time to take it out into the field and see how it performs.
7) Possibly Upgrade to a Recirculating Sluice
At times there isn’t any running water accessible to use with your sluice box. quite a number of rich gold prospecting streams dry up immediately the summer sets in. so to make your sluice box perfect for such places you might consider making it a recirculating sluice. This upgrade uses a pump to recirculate the same water through the system, allowing a limited amount of water to be reused.
The most important thing you need to turn the sluice box you have just built into a recirculating sluice box is a pump. Finding the perfect pump for your sluice box can be a daunting task but these should not discourage you from trying. You should start by checking online or in boating supply stores near you as these are the best places to find the best pumps for the job. In addition to the pump, you will need to find good lead acid batteries or any other portable source of power to power your pump if you go for an electric pump. This is quite important as working with a pump will mean that you have power the pump so that it can supply the water to your recirculating sluice box.
To turn your sluice box into a recirculating sluice you will need to build a cradle to hold the sluice box over a tub. This is the only way to collect back the water that you have used so that you can reuse it. You will need to mount a splash board diagonally at the lower end of your sluice so that it directs the water filling out of that end back into the tub.
With a recirculating sluice, you may find it difficult to feed water evenly into the sluice from a hose pipe. The best solution to this is to use a spray bar at the upper end of your sluice box. A spray bar is a simple PVC pipe with a number of holes drilled on its lower side to allow water from the pump to flow into your sluice evenly across the upper end. You will also need a valve to control the water flow through this spray bar. You can attach the spray bar to your sluice using simple steel strappings together with bolts or screws.
Once this is done consider working on other important areas that you still think needs some improvements. For example, how do you adjust the angle of your sluice box when in use? These are an important place you can make some adjustments to so that you can have it work perfectly. Also, check on how your pump works and see if you need to make some improvements to it. This is important as it will help make it work even better.
Designing an efficient recirculating sluice is considerably more difficult than a standard sluice box, but it might be worth considering if you are in an area where water is a limiting factor.
Also Read: Review of the Keene A51 & A52 Sluice Box
And: Find More Gold in your Sluice with these Tips
And: Classify your Gravels to Retain More Fine Gold
To many gold prospectors, building their own homemade sluice box is not only a cost-effective way to get a quality sluice box but a great way to create a custom made sluice box that perfectly suits their needs. You may find that a carefully constructed homemade sluice box will give better recovery rates than commercial models.
Sluice boxes for gold recovery are simple to design and build. All you really need is to have a basic idea of how a sluice box work and to take a look at a number of commercial sluice boxes to get some ideas for how to design one for yourself.
If you don’t own a sluice box yet, you can build one today using very simple materials that you can get from any hardware store. Find the materials that you think would work best and experiment with different designs until you’ve found the one that gets you the best gold recovery rates.
Next: The Blue Bowl Fine Gold Concentrator