Building a suction dredge for gold prospecting or underwater excavation requires careful planning and understanding of the components involved. Below is a step-by-step guide to constructing a basic suction dredge.
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Components Needed:
1. Engine/Pump System – Powers the suction.
– Small gasoline engine (e.g., 2-5 HP) or electric pump (for smaller setups).
– High-pressure water pump (capable of 100+ GPM at 50+ PSI).
2. Suction Hose & Nozzle – Draws in material.
– Reinforced suction hose (2″–4″ diameter, depending on scale).
– Jet nozzle or power jet for creating suction.
3. Sluice Box – Separates gold from debris.
– Adjustable riffles, matting, or expanded metal for trapping gold.
4. Flotation System (for floating dredges) – Keeps the dredge buoyant.
– PVC pontoons, barrels, or foam blocks.
5. Frame & Support Structure – Holds everything together.
– Aluminum or steel tubing for durability.
6. Pressure Hose & T-Jet Assembly – Creates water flow for suction.
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Step-by-Step Construction:
# 1. Design Your Dredge
– Decide on size (2″, 3″, or 4″ hose diameter).
– Choose between a floating dredge (for deeper water) or a backpack-style portable dredge.
# 2. Build the Frame
– Weld or bolt together aluminum/steel tubing to support the engine, pump, and sluice box.
– If floating, attach pontoons securely.
# 3. Install the Engine & Pump
– Mount the engine and pump on the frame.
– Connect a pressure hose from the pump to the T-jet (venturi system).
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# 4. Assemble the Suction System
– Attach the suction hose to the intake side of the jet nozzle.
– The T-jet creates a vacuum when water is forced through it, sucking up material.
# 5. Set Up the Sluice Box
– Position it at an angle (~5–10 degrees) for optimal material separation.
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t with riffles, miners moss, or vortex matting to catch gold.
# 6. Test & Adjust
– Run clean water first to check for leaks and proper flow.
– Adjust