Hoop if you are replacing any of the thru hulls that are below the water line, or touching the water, it would be a good idea to BOND them to the dyna plate if you have one, or at the very least bond to the rest of your system.
Asside from cost the manufactures have switched to plastic to avoid the "burning" of the S.S. and bronze due to galvanic and electrolytic corrosion. Properly bonding minimizes the potential of this happening.

Another little tip for anyone considering this project; If the backing nut does not sit flat against the hull all the way around, or if the hull is thin: make a backing block out of Azac (the builders grade starboard). The block spreads the pressure evenly on the hull and also adds strength at the base of the thru hull fitting where it is most likely to fail.

Sorry for the , carry on.

P,S. thanks for sending all the rain back up north .

even tho all mine are bronze.......nice added piece of mind...Bilge is WAy up out of the water that has a plastic....

Mine is on a trailor and when in the water it is not more than 4 days. Electrolisis is not much of a worry for me. Thanks for the info. I will remember it if there is any sign of a problem. As promised here are some pictures.



The outer side fell off and left a mess with nothing to keep it from falling inside the boat leaving a 2 inch open waterway into the boat. This is on the 25 proline shrimp boat.




The opposite side has a space big enough to slip a penny into and it is on the forward side of the fitting.





Although not set in place they look good just being there. I took a picture of them early this morning before I brought the cat to the vet. 50 miles one way. Installed most of them and hooked up hoses when I got back. Figure about 5 more hours on it tomorrow should finish the project. Had to have one machined down to fit in the space. It was too long. That only cost me 33 dollars.