I have to pre classify to .25 inch . With yours it falls out the back and down the shoot what is the diameter of your metal with holes on top
It looks like your sluice is about 4.5 ft long shouldn't lose any fines
The home made wooden high banker in question began as a primitive sluice box and through trial and error,,, progressed into an effective portable high banker. The thought process was to build a more efficient “Long Tom” that could capture fine gold as well as the larger pieces. To assist in a better recovery, I chose to include a 1” drop within the sluice box. As seen in the pic, this 5 foot sluice began with a diamond mesh grizzly. While this was a step above panning, it was adequate at best for separating larger gravels which caused many plug ups. In addition to this, the use of a small bucket to wash the gravels was a bit time consuming not to mention back breaking work. This experience was short lived as the grizzly (diamond mesh) portion was quickly replaced with round metal bars and a ”wash plant” built with PVC spray bars, a bilge pump, and adjustable stanchions for support. One again, these metal round bars (as seen in photo 4) proved to be a nuisance as they too caused plug ups. In the end, I resorted to 1/4” (.25 inch) punch plate holes which solved the plug up issue. From start to finish, it was quite a transformation that all took place within a single season.
Over the years this sluice box has produced some outstanding gold and has made a name for itself as “The Long Tom IdahoGriz.”
If anyone is interested, I can provide detailed pictures with measurements of the grizzly and how it performs.