DIY 250w HPS reflector, let's brainstorm

I am about to install my 250w hps

But don't have a reflector

All I could find on this board is a good solution made from an old PC case, but those I don't have.

I have an idea to cut up a 5L bottle in 2, staple some reflective material there, but am afraid it might melt.

Oh, and I have an old sink that can be used like one!

Go to your local hardware lumber store and go to the ductwork section. They sell galvanized steel in sheets about any size you need. I think 18"x18" and up, also you could just get a piece of 6 or 8 inch tubing and cut it down the sides and it will already be bent in a U shape. Just use your imagination, a sheet of steel and a pair of tin snips and the polish it up a little when you are done.