Hello!

So I recently got into creating closed environment plant terrariums and for Christmas my in-law got me this really cool container. However, it does not have a rubber seal and is relatively loose (I can wiggle it around when its on the container).

I want to make it airtight and I was thinking if I find the right product I could coat the edge of the lid with a rubberized material so when I close the lid it fills in the spaces. I wasn't sure if something like 100% silicone 1 would give it a rubbery texture and hold or if it would harden and have no give to it.

Any suggestions on what kind of liquid I could paint onto the lid of the jar and have it harden into some sort of reusable seal?