brimc76 has the correct answer. I posted this somewhere (cannot remember where at the moment) on how to properly seal the lids. It works like a dream!

What is important is that you remove all of the lid seals, including the rubber one that is closest to the lid. You then spread a very thin line of silicone around the area where the rubber seal normally sits inside of the lid. I mean a real thin line of silicone, otherwise closing the lid will be a problem. I tried to achieve a line of silicone about the thickness of the glossy seal that is used in the lid. I used a cheap brush that is normally used for applying solder paste to spread the layer of silicone. You DO NOT place any silicone on the seals but rather only on the hard lid.

Now let it dry over night. DO NOT put the rubber seal on the wet silicone. The next day re-assemble the lid with all of the seals (rubber and glossy black thin seal) and you should be good for a very long time.

Hope this clarifies the technique.

Kind Regards,