A drywasher is actually a fairly modern device despite the relative simplicity of how it works. While the origins of the drywasher are still somewhat shrouded, the early machines were not doubt operated by hand in rugged conditions when wet washing techniques were simply not applicable.
Materials are fashioned into a simple framework that is usually made from wood, although some newer designs are now made from aluminum and other materials. Before screens were invented and perfected, the sorting of gravel was done by hand by eliminating the larger rocks and examining the smaller ones for traces of gold. Sorting by hand is a very time consuming process and tiring as well, especially to those who have mined for gold all day.
The drywasher speeded up the process considerably and allowed for sorting to be done at a considerably faster pace. While not as efficient as the modern screening processes we use today, it was sufficient to help those fish through the gravel to find gold nuggets.
How Does a Drywasher Work?
The principle of the drywasher starts with the puffing of air from the bellows up through the fabric which is located on the bottom of the tray where the materials are concentrated. The vibration of bellows themselves or when using a blower-type model, the offset weight used on a fan blade which is turning when the air is being drawn from underneath the tray.
The air causes all the materials that are very light in weight to be blown away while the vibration settles the heavier material towards the bottom. However, the most interesting aspect of the drywasher is that static charge is built up due to the combination of the dry conditions and the air being blown through the bottom of the tray. This causes materials which hold metallic properties to be held in place assuming they are light enough while the heavier materials collect elsewhere.
Modern improvements to drywashers have made them far more practical, although they still do not rival traditional wet methods such as dredging or sluicing. What is true is that drywashers can perform at a high level when separating gold, and are really the only viable option in many of the more arid mining regions around the world.
Basically, the drywasher separates the finer materials that may hold the gold from the rest of the materials present. Considering the materials used in construction and the process itself, it actually works rather well when sorting through the gravel, dirt and debris to find gold.
When Should a Drywasher Be Used?
Drywashers are very well suited for areas in which water is not around. This means that drywashers actually expand the ability of gold seekers to search in areas that have dried up in order to find gold. They work best when conditions are extremely dry. If the ground is damp or wet they will not operate properly. Even in extremely hot and dry climates like the desert Southwest, they work best when the material that you plan to drywash is dig up and laid out in the hot sun for a day or two to completely dry it out.
The drywasher is an important part of mining operations when not enough water is available. For those who are seeking an alternate way to sift through materials to find the gold, drywashing is the answer. If you are in an areas with water, then traditional placer mining methods are more efficient, but places that are dry with no water, the drywashers are an excellent tool.