The Undercurrent

An undercurrent is a product that was invented in the pioneer days in order to get every last piece of gold and they have been known to recover values. The undercurrent is a complicated piece of equipment however it can be put together and carried to a certain location. It used to be utilized in a bigger operation where a weekend prospector just so happens to find a sand bar that would pay out sweetly. In any other case it was simply not worth putting together at all.

In order to work correctly, an undercurrent needed a great amount of sand and raw material and it also needed a lot of water and volume since it runs from one to seven sluices all at the same time.

The main sluice is placed on the highest level and it is usually put up with common riffles. At the area where the water goes in and the material is shoveled in, there is a type of pole riffles, log riffles, rock riffles or sort of a rail road track that serves to break up the material. After the material has gone though this area it goes inside the main sluice. In most cases this grizzly had a crisscross pattern to it that had a one quarter inch size and it was usually as little as one eighth of an inch. Obviously for this to be built it mean a good deal of material was going to pass over the grizzly to then go into the main sluice and in many cases at this point is where the coarser gold and some of the vine valuables were recovered.

All the way through the grizzly the water and the finer parts of the sand then passed into a feed box. This feed box took care of then carrying the sand and water from three to six other sluice boxes that had been set up with riffles and these are what are known as the undercurrent and due to the fact that it was lower than the main sluice and a smaller current runs through it, it was known as the undercurrent.

It used to take a very big amount of sand to go into the main sluice to get a lot of the sand down into the undercurrent but the sand that was concentrated there obtained a lot gentler sluicing action and very fine particles of gold were able to be recovered. Every sluice is covered with a blanket, canvas, gunny sack, or any other type of material and the riffles are usually built lower down. It is not common most beginners will ever need to use or consider using something like this, nonetheless when it came to bigger operations or in cases in which a lot of fine gold or precious metals etc was being lost, it was and is a good alternative.