I'm in the process of adding water pick ups for Whipples. I can't go thru the transom so I'm going to have to go thru the bottom of the boat. My question is how to I seal everything up once I go thru the bottom? The pick ups themselves don't have a flange or anything outside the hull so once I put an 1-1/4" hole thru the bottom how do I seal up the tube sticking out the bottom of the boat? Any help (and pics) would be greatly appreciated.

Never seen a thru hull pickup without a flange. My 43 Black Thunder has the pickup pipe hole filled and the escutcheon flange set in 5200.

Attached a photo. There is a flange but only on the inside of the boat - nothing goes outside.

That seems insanely too long.

They still need to be cut. Just received them from Teague.

I'd cut the hole. Then I'd resin over the cut and exposed glass. Then I'd seal the flange to the hull with sealant of choice. I'm not a fan of 5200 because of how runny and permanent it is. Maybe 4200 is thicker.

Inwas planning to resin or epoxy over the exposed cut and was thinking of using MarineTex to seal it all in. Itl be pretty permanent but I don't see how else to.seal of all up really well.

So I'm assuming your flange is on the inside of the hull, not outside?

I'mdoing this on a 46 Black Thunder