Look for the extra wide stuff made for the bar-b-que. I think it's around 18" and quite a bit thicker. Fold that up around the edges of your pan and it won't leak. Trying to interlock the edges of the regular width foil is futile. BTW, I assume you are pre-baking the crust? Keep in mind too that a cheesecake is not really a cake - it's more of a custard. As laurenlulu said, keep the temperature down around 200-225 or so.I have already tried tinfoil and I can just not get it to work.