The various holes are taped off or capped, then the entire conical was lowered in a tank of weak acid with electrodes attached. Chunks of solid copper are atteched to the other set of electrodes. Between the current and the acid, copper is moved from one the chunks to an even coating on the fermenter. Not sure if any more will be made, there are a couple glitches that need to be worked out first. But it does look nice, gives the pub an older look. Now to finish the kegerator and redo the walls and floor....