[seanc]

I've never heard that vinegar could even be used for the electrolyte, and it would seem contradictory.

Zinc is very reactive, and dissolves easily in acids. Vinegar is an acid, and can be used to strip or activate zinc surfaces. So it sounds like your vinegar based electrolyte might be working against itself, stripping the zinc plate almost as fast as it puts it down?

Are you using zinc anodes, or have you dissolved the zinc in the vinegar first?

Caswells electrolyte has zinc dissolved directly in the electrolyte, so anywhere the fluid finds its way into, will plate. Some zinc is transferred directly from the anodes to the parts, but quite a bit of it is simply to replenish the zinc plated out of the electrolyte.

Sean