Hey bud, just a suggestion, but tin-foil is very overrated... meaning it is one of the worst reflective materials in that it distorts the refraction of light into thousands of directions! Crippled-up tin-foil is the worst, you may want to consider white paint or you can get Mylar in the form of a emergency/heat blanket from a retail store like Target or K-Mart, etc for $2-$3!!! Mylar is the best, looks a lot like tin-foil but works a million times better at saving your unused light!

Good luck!