Hi Ben, theres a new gadget out called HOLY MOLY DIRT DIGGER or there abouts its hand driven but utilizes a vacum for escavation.
It sinks holes up to 14 foot only problem would be large stones id say. Have a look
Penny weight
As you can see dowels on either end entrap a smaller board tight against the wall. In return the smallar board entraps the bigger board. Hardwood is a must
There is a reason professional miners and serious prospectors use miners its the best gold trap. Cells have a tendancy to block up with pyrites and garnets plus your limited to the amount of material able to be fed threw.
Some impellers are plastic so heat method is out. I use a chain wrench wrap cardboard or rubber strip around the impeller and presto. Also a good squirt of wd for a 24 hour soak helps.
Use a clean up tub, surely you have a tub or pan you run on the end of you banker when cleaning up. Just find a stone to weigh it down an another to anchor the intake aswell.
Ballarat gold this would depend on where you dredge, dredge size and dredge technology. These days a Dredge is able to recover micron gold. A two man team with a 6 inch can move enormous amounts of material. The trouble is getting past water and land if passed your proposal is then put in the...