How do I get the knob to stay on my tank?

[fknighton]

This may sound stupid, but every time I silicone the plastic knob onto my tank lid, it doesn't stay long. I usually end up using a hunk of silicone as a knob, but it eventually has to be replaced too. I can't imagine that everyone has that problem. The lid is 2 pieces of glass with a hinge in the middle. Any suggestions? Fran

[Dancing frogs]

Drill a hole through the glass, and use a screw.

Or you could try some epoxy...if you do, I would get a wood knob instead of the plastic one, as not many adhesives stick well to plastic.

[Phoenix]

I would worry about drilling the glass, it breaks so easy. Try some of the White Gorilla Glue, that stuff sticks!