I don't know a lot about the 1-series bodies and the exact methods canon uses to weather-proof their professional line equipment. I've read about something like an 0-ring where the lens and the body are joined. I've read that filters, such as in the case of the 16-35mm L zoom, are intended to complete a weather sealed system.
I recently purchased a bunch of professional grade filters to keep dust out from the front of my non-L lenses and for basic protection of my expensive L lenses. I shoot a lot outdoors, sometimes on the beach where sand is blowing about. I did a search and did not find anything on the topic - but couldn't I just apply a cut strip of gaffer tape where the lens attaches to improve the overall sealing of my camera? Has anybody tried this or attempted any other make-shift weather sealing?
Obviously if you're switching lenses this would not be very convenient. I have 2 bodies with a short-to-long zoom and a long-to-telephoto zoom so I really have no need to switch around with lenses.