Copper packing lifespan

[Elfmaze]

I'm still trying to decide between stainless and copper for the main body of my build. I understand the copper binds with sulfites to form copper sulfide which can later be dissolved with a citric acid formula but in doing so is the copper used up? How often does copper packing need to be replaced, do the walls of the main body ever wear through?

I understand there are 100 year old copper stills.

I would want to use stainless because I TIG weld so stainless is not a problem for me and adding triclamp ferrules is easy.... I've never soldered copper, but i will work with copper if there is a difference in product

[Bugflipper]

Copper packing should be safe indefinitely with the food grade level of acids it's cleaned with. It is cleaning the collected sulfides and such, not eating away at the metal. Can't comment on going with stainless, my only experience is with copper. IMHO you absolutely have to have copper in the vapor path to get rid of the off flavors. That's what discolors the most from the sulfides.
BTW if you have the skill to tig then brazing or soldering copper will be a no brainier for you, so nothing to be uncertain of. I imagine there would be plenty of videos on YouTube on it. If a fellow out in the woods with a kerosene torch can do it, a welder isn't going to have any trouble at all.

[heartcut]

The copper does erode when it binds with the sulphites, but the erosion is usually pretty slow. I've had copper mesh in a still that ran every other weekend for a year at a stretch (just rinsed after every run, it looked and felt fine, put it back. Commercial stills eventually just get too thin, but it takes a long time to get there.