Is this a bad idea???

[rcbildr]

I noticed the front seam on the roof of my GMC where the roof panel meets the drip rail has rusted loose....pretty much from the middle of the windsheild going around towards the passenger side and stopping over the passenger door. The roof top feels pretty solid close to the rail and the underside of the drip rail does too. I'm thinking the spot welds have rusted, but the surrounding metal is still good...at least that's what I'm hoping for.

What I was thinking of doing for now (just to keep the water from going in to the cab) was to clean up the area and run a bead of sillicone aound the drip rail. With the rainy season here I need to do something until I can get the time to weld it up properly. Is this a bad idea? Any help/ideas will be greatly appreciated.