You stack classifiers to get you material to consistent sizes for running in your sluice or panning.
Different material sizes in the same run or pan will cause you to lose gold due to the various eddies formed by mismatched sizes
I use a one gallon bucket with the bottom cut out and a piece of 1/2" hardware cloth that fits. I wash everything in five gallon bucket and dump out the one gallon sieve, then run the classified material through my drop riffle sluice.
After I get a sluice clean up panned down to mostly black sand I sometimes use a wire kitchen strainer to clean out larger heavies. I don't care to carry a duffle bag full of classifiers around. That's the way I like it anyways.
Awesome! .... I wonder if I could get this going on my rocker. Currently you have to give the classifier 2 or 3 good shakes while pumping the water to get the smaller stuff through. The pumping action is actually a Breese but the constant shaking gets annoying.