No, sitting in a cool garage on a concrete slab that stays cool. Could be. Strange that this topic is coming up on APUG right now. I was just reading about Becquerel's method:

http://www.alternativephotography.co...-daguerreotype

and thinking about all the silver that's in that jug of fixer in my garage, along with a stack of un-etched copper circuit boards. But I don't know enough about silver plating to try it.