Thru Hulls leaking

[Stephen]

Can anybody share the best options for my leaking thru hulls? I have a 1980 23 footer with an enclosed transom and a bracket.The fish box up front is leaking through the plastic thru hull and I suspect the two that are in the back
that go through the floor are cracked and also leaking. Should I change out the one in the fish box to a stainless and the ones in the back also to stainless? I also hear that I should plug the ones in the back that go through the bottom of floor and either go out the back or the sides above the water line. Which way is best and how should I approach this project? I have a buddy who is a professional fiberglass man. Thanks for all the info in the past!!

[Blue_Heron]

Get rid of any plastic through hulls below the water line. Go to bronze or stainless and use 3M 5200 sealant. On the bottom of the hull, I would use bronze because it will sustain impact better than stainless. The through hull on my forward fish box is bronze.
Dave