Whether the lid pops completely off or raises on a sideways hinge, Windmill lighter tins, Altoids tins, tobacco tins, Sucrets tins and any other similar types of tins are all built basically the same; the bottom is watertight and the lid fits tightly completely over and around (surrounding) the sides of the bottom part. I have always just wrapped a piece of electrical tape all the way around the four sides of the tin a couple of times. To be redundant, I do not put any tape over the top nor the bottom of the tin; I wrap one long piece of vinyl tape sideways around the tin a few times. This covers and waterproofs the seal where the lid fits down over the bottom, since the top usually stops about halfway down the sides. Does that make sense?