Are you familiar with Fresnel lenses Jen?
I saw some info on these suckers on one of the DIY hacking sites, Instructables, or maybe it was the King of Random? (I think the 2nd one - you can google lots of Info). I got mine free from a large TV found on the side of the road on trash-day. I've melted Nickels and Pennies with it in the driveway with the kids. Prrreeety sure it can handle some beeswax!
The poor-quality projection TV's of old are the best source - you know the old-style TV's that are furniture size, and you have to sit DIRECTLY in-front. Any distance to the side, and the pic is all blurry and dark? THOSE ARE THE BEST!
On the face/screen, there are 3-layers of plastic sandwiched together. Middle one is usually a large fresnel lens (like the one's in Lighthouses that focus the lightsource into a beam?) Inside the TV is a projector-screen, it bounces off a mirror, and goes through the lens to your eyes. We're using the lens to focus the sun's light into a small area (again, the cheaper TV's work better here, as anyone who's tried to watch the superbowl w/ a group of friends will testify!). I just made a cheap frame w/ some wood-scraps to hold it, and you have to test the sides (one will work better than the other). WEAR SUNGLASSES. I couldn't believe how intense the light was. It took a few minutes of cooking, but I turned a stack of pennies and a couple nickels into a puddle one afternoon last summer. Kids LOVED IT!
- K