Let this be a concrete model all should abide by when sealing your oil pan. The goal is to seal oil from leaking "out". You don't need a huge bead of silicone or even a 1mm size bead either. All you need is to dot the perimeter of the oil pan rail on the block and oil pan then smear the silicone as shown in the images below. From their you add silicone to the outside then proceed to run your finger over the two rails (pan and block) to make a seamless seal the entire way around the block. To seal the oil pan ends (half moons) you put the tip of your silicone tube and begin to pump silicone in till you see it fill the gap...then go over that area with your finger to make it a seamless seal just like the oil pan. From their you are 100% covered.
