lab glass would be better than pickle jar, either will break from changing temperature thermal shock, I have busted a pickle jar once (learned my lesson getting my gold out of sand bath not fun) but as long as I keep aware and don't change temperature fast, the pickle jar has survived many a distillations, also I have used an electric hot plate.
at 2ND hand store found a few coffee pots pyrex that look like lab glass erlenmyer type, I made a teflon lid with hose and have used it directly on electric hot plate several times to distill out my acids (like from concentrated acid peroxide and copper solutions to make clear acids to add to other processes while dehydrating the copper salts to save), I have bought some of that fancy labware distilling kit and all, never used it yet,
I like my cheap glass and second hand lab ware, maybe someday Ill try that fancy stuff out. but give me a coffee pot electric hot plate a welding torch, propane torch, mason jars, pyrex type skillet, pickle jars, some other common kitchen stuff from the junk store and I am happily getting those metals.
the cell seems finicky at times, probably PH, and copper content, but it works good for breaking the metal down to powder's so my acid volume used is less and I can dissolve them easier, the nitrates used did not seem to make much detectable gas(maybe dilution of my jar cell?), but when loaded with copper and PH low would get green foam usually little water and nitrates or settling powders and cleaning out cell was answer, there was one time when it seemed to have made ammonia (or at least it smelled like ammonia to my ole nose), but that only happened once,if you do get an ammonia smell with silver don't dry out your powders, I wouldn't dry my powders anyway's, if silver in ammonia add hydrochloric acid, to change PH and make it safer. as silver and ammonia is not something to mess with, can be dangerous.
it may be better if they are high copper content to use a chloride solution as copper chloride and bag the Anode, haven't tried that yet, basically copper electrowin cell.
gases of cell's and the product's they form should alway's be considered.
for electrowinning the lower voltage would be great, you may even be able to get a better plate (at least more silver to stick to cathode) this was not my intent, which for me was only to disolve the metals to powder and not plate them out, which once I got silver more pure after disolving in acid and preciptating back out, can use to inquart gold, then and after collecting enough of it in a more pure state would look in building a silver cell to refine the impure silver.
this information is just some things I have done not the best way maybe but I was happy with my results. try them for fun if you like, but study as much as you can and be safe. could be some things created in the cell I don't understand yet?
