OK, I have been having a hard time locating a piece of aluminum or plastic (ABS or policarbonate) to put there that will not cost me an arm and a leg. SO far, every place here (local purchase) wants to sell me a 8' X 4' sheet. I just need a couple of inches worth, so that's not in the cards. Looking around the house to see what I have available, I came across a Rubbermaid case that I can cut up. Do you think this will be strong enough and will withstand the heat?