[T3] My Car Has Cancer.

[Marklist]

I've got some pretty serious looking rust.  It's at the bottom of the 
rear, right side window.  I'm assuming it is from rubber failure.

I'm not in a situation where I can to a proper paint job.  I'm hoping I 
can just sand it off and primer the spot.  My concern is that it is from 
the rubber failure.  It looks like the original rubber.  I'm afraid that 
if I take out the window to get all the rust I will ruin the rubber.

Can I just use some silicone sealer as a temporary, but really long 
term, patch for the seal?