That was where I got mine, I asked at a TV repair shop if they had one, and they gave me two! Setting the asphalt on fire was entertaining. We built a simple frame for it out of frame components at the craft store to make it easier to point.<p>My goal was to build an aluminum can smelter. At the time I had this idea that I could crush a diet Dr. Pepper can with my hands (this I <i>often</i> do) and then slide it down into a crucible at the focal point of the lens, and have it melt and drip into a bucket of water below, creating aluminum bb&#x27;s which would be much denser than even crushed cans. The problem however was that aluminum oxidizes before it melts, so in the ideal set up you really want it running in an oxygen free environment. Way more work than I wanted to invest.<p>Later I discovered induction heating (which you can do with a windmill, some magnets and a coil of wire around a piece of steel (or aluminum).