How To Make A Diy Blue Bowl Gold Concentrator. How To Make A Diy Blue Bowl Gold Concentrator. HOW_TO_RUN_A_BLUE_BOWL IOWAGOLD. Blue Bowl micro Gold recovery system Hand panning concentrates smaller than 20 mesh is difficult and tedious, even an expert panner loses a lot of micro fine Gold.Blue Bowl Concentrator Collectibles , eBay,Blue Bowl Gold Concentrator.May 16, 2016 The Blue Bowl Concentrator is perhaps the most popular tool created for this task. Prepping A New Blue Bowl Before beginning to use the blue bowl concentrator, the user needs to make sure that the interior of the blue bowl is dry and free of.