Dredging and Related Topics
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Gold Dredge Tip #1
Do not run your dredge motor without an air filter. Even though it may not look dusty, microscopic dust will score the intake valve and the combustion chamber, greatly reducing the life of the engine. Change the air filter a minimum of once per year.
Gold Dredge Tip # 2
Change the engine oil after the first 5 hours on a new motor. This is "break-in oil." After that, change the oil every 20-25 hours running time. Typical dredge motors do not have an oil filter, and the oil must be changed more often than your car. Use ONLY grades and weights of oil recommended by the manufacturer. For Briggs & Stratton engines, ONLY 30W detergent oil (not 10W-30 and not non-detergent oil).
Gold Dredge Tip #3
Do not leave the dredge engine's gas tank empty, even overnight. When done for the day, top off the tank with fuel to prevent condensation from forming in the tank.
To store the dredge engine at the end of season, hook a water supply to the pump (do not run dry). Fill the tank with fuel treated with a fuel stabilizer, such as STABIL. Run the engine for 5-10 minutes. Cover and store in an area not susceptible to gas fumes buildup.
When dredging, only run the engine as fast as necessary to provide good suction at the nozzle...not (necessarily) wide open. You want good suction to pull the solids all the way to the sluice box, but decreasing the speed of the water provides better separation of fine gold.
When operating the suction nozzle, don't "jam" the nozzle into the gravels. Doing so will cause frequent plug-ups and overfeed the sluice box. The ratio of water to solids should be about 3:1 (3 parts water to 1 part solids), but no more than 2:1.
Don't try to max out the size rocks that go up the suction nozzle. Even though you might have a 4" nozzle, letting a 3 3/4" rock to go up the hose will have a good chance of getting lodged and plugging up the hose at the joints. Instead, take the extra time to pull them out of the way.
Take a round file and taper the inside of the jet tubes. This little amount of tapering can help in prevent many plug ups.
Use ribbed carpet under miner's moss in the sluice box. This will do a better job of catching fine gold better than miner's moss or ribbed carpet by themselves.
Keep a roll of duct tape (100 mph tape) handy. Good quality duct tape can seal holes in your suction hose, make temporary repairs to pontoons and other dredge parts, and a host of other uses.
Paint all tools bright florescent orange. Tools are much easier to see when they are bright orange instead of black. This is especially useful when working in murky water.
Take only the tools down that are necessary for the job. In taking too many tools underwater, you run the risk of losing accountability. Tools can be covered with cobbles easily.
Use a rubber "dead blow" hammer (2 1/2 lbs) to assist in unclogging the suction hose. The rubber head will not damage the hose and the "dead blow" design gives that extra punch.
Repair holes in your suction hose as soon as possible. Gold "crawls" up the hole and can fall out of a hole in the hose.
Keep a bottle of isopropyl alcohol handy just in case gas or oil are spilled in the sluice box, cleanup tubs, classifiers, pans, or anything else used to process concentrates.
If you see an oil "sheen" anywhere in your concentrates, use one or two drops of dishwashing detergent to break up the oil.
"Reprinted with permission of The Rocker Box"