Sorry I thought those forums were open to anyone. I will ask the owner about changing permissions so guests can view the threads too.
Here's the thread I copied from there:
I didnt get a chance to go prospecting so instead I worked on the fluidized bed gold trap for the highbanker. The purpose of the fluidized bed is it should catch any size gold going out the highbanker and instead hold it in the trap. A fluidized bed works by pumping in a low volume of water from underneath, just enough to keep the material in the trap suspended in water. Heavies should sink deeper into the water while lighter tailings will float on out the back exit. I will have a pressure gauge when I finish the PVC so I know how much pressure the chamber is getting. Fluidized bed traps can work with as low as 1 psi.
Here's the little fluidized bed box I fabricated, 13 inches wide by 10 inches long.
Here's the spray bars, these are pointing downward with about an inch and a half of clearance underneath them to the bottom of the trap. This way there's room for the heavies to settle into the trap and sink down into the water.
Here's the alignment bars to keep the spray bars in the right place and off the bottom. Also you can see the silicon sealer I used on the seams.
My huskies, Kara and her twin sister Kira came by to see what I was doing since the drilling was making a lot of noise.
Here's the trap almost done, just needs more water proofing, painting and then mounting. And of course I have to seal the water inlet sides.
Here's how its going to be mounted to the end of the highbanker. I am going to have to figure out a way to swivel it up so ground clearance wont be an issue when rolling the high banker over rough ground.
Of course it still needs paint and more little stuff but its a good start. I have almost all the PVC now to hook it up to the other pipe, but I got to get one more Y piece first.
The exit side of the fluidized bed gold trap is 5/16s of an inch and the entrance is 4 mesh. But I can easily swap the screen out if needed for different mesh sizes.
Also something I learned is you should slant the exit grizzly somewhat down, otherwise material will find a way to hang up!