[Greg Needel]

it is actually alot easier then you think. All you need is well placed gaskets and o-rings. There is a really good chapter in the machinists handbook on them, but the basic gist of things is you have 2 surfaces (like panel that comes off, and the plate it attaches to) and you cut a small groove (dimensioned to the size of the o-ring). When you put the 2 parts together it squishes the o-ring and creates a water proof seal. If you open most any electronics that are water resistant or proof you will see one of these. A good cheap example if you wanted to find one is a shower radio.