Just got a new bottle of KG12 from KG Coatings, opened bottle and smelled it, seems to have ammonia odor but the boss down there says it does that after it gets oxygen or has been on shelf awhile...the bottom line here is that I know this stuff works, but I remain leary of leavin it in my barrels for extended periods of time, Bore Tech Eliminator that I purchase three years ago remains unchanged, no odor and removes copper..