So I've been looking around at various home made accessories here, like vortex and ash catchers, and was wondering about safety issues with the components you use. If one was to take an old tin coffee can, cut the bottom out, and toss it on hot charcoal to burn the paint off would that be safe to use as an ash catcher now? For a Vortex I have a bunch of dog stainless steel water bowls and pails that would make a slick vortex. How about metal duct work. I have all this stuff laying around that could be repurposed and work as good as the store bought stuff. I'm concerned in regards to any safety issues that might come off/out of them when in use. Thanks.