So far these record bowl are great for things like fruit that are pretty big, but they aren't very good for snacks like pretzels because of the hole in the center. In order to plug these holes you'll need a propane blow torch. The first step is to cut a little square, about 2cm on the side, of vinyl out of a spare record.
After striking the blow torch and adjusting the flame, use some kind of tongs to hold the vinyl square directly in the flame. Only torch the vinyl long enough to get it soft, not long enough to catch it on fire.
When the vinyl is nice and soft, set it directly on top of the hole in your bowl, and pound it into the hole. You have to be fast because the plug will cool quickly. When you are done the hole should look something like this.
A few of these plugs are good enough to be water tight, but most still leak very slowly. But they are all good enough to keep crumbs from things like chips or cookies from spilling out the bottom.