Re: What to seal the Bilge pump through the hull.
Jonathan3206, regardless of what you are doing, any through hull fitting can be sealed using 3M 5200 or 4200, Boatlife, or Attwood's marine sealer (available at Walmart for $8, I think its really 3M 4200). Any of these will do a good job. My personal preference is the 4200 or Boatlife sealer. They will let the parts be removed if need be. Otherwise, use 5200,
Don't use silicone.