Replacing vertical thru-hulls in a 76' 23 SF

[John3325]

Whose taken on the task before?

Thinking about replacing the ones in my 76' 23 just to say they are done and never have to worry about them. Reason for the post is I am looking for some insight on what to expect.

I have redone mako thru hulls before by sanding some PVC pipe and glassing into the transom. Can this be accomplished for those pesky vertical thru hulls that go straight from the deck down through the bottom of the hull? Should I just get new bronze and buy the tool and seal with 5200?

Any insight to taking on this project is greatly appreciated.

[Snookerd]

I have them as well. I need to address mine soon. From what I have seen from others, the tube goes through a block of wood and is a royal pain. I’ve heard of a couple people going back through the original location and most glassing in The original location and rerouting through the transom. The most creative that Carl put together was crisscrossed drain pipes out the Stern. Intention was if water came in because of excessive weight on one side, the chances were slim that water would move up the tube heading across to the other side drain in the deck.

[Oldboat]

They are easy to replace with the flaring tool. Both my blocks were solid and look great when I remove them last year so inless u had water getting in there u should be good. 2 new brass tubes 5200 and another person to hold bolt on the other side of flairing tool and your done in 2 hours. Leave no more than 1/8 inch on side u flair, to long and flange will crack. The flairing tool u get may be to short pick up rod at Home Depot and trim to correct length . Might as well do your fishbox drain while your at it

[Oldboat]

Not a great pic but u can see block on left

[John3325]

Awesome thank you for the picture too. I had no idea it went through a block.

Any tricks to knocking the brass tube out besides curling the lips in and trying to knock loose with a flat head out the bottom?

[Snookerd]

Originally Posted by John3325

Any tricks to knocking the brass tube out besides curling the lips in and trying to knock loose with a flat head out the bottom?

Original tubes are not brass, they are the nylon type.

[FLexpat]

Originally Posted by John3325

Awesome thank you for the picture too. I had no idea it went through a block.

Any tricks to knocking the brass tube out besides curling the lips in and trying to knock loose with a flat head out the bottom?

One of my wooden blocks was mulch/jello. The other was fine. Both old brass tubes were badly corroded (40 years old).
I used a flat blade screwdriver and hammer to curl the lips in from the outside and then a socket with an extension to drive them up and out. Easy.
My replacements are 1-1/4" instead of 1" (50% more flow area). I used some 1-3/4" OD fiberglass pipe wrapped with 1708 as the new tube/block (2"OD after that). Wrapped the FG pipe first then cut it to the right length and angle. Smeared ends with thickened epoxy before inserting, then used the thickened epoxy to build a fillet around the upper and lower joints. Put a couple of small pieces of 1708 over the joints just 'cause I'm neurotic and hate leaks. The hard part was getting the new FG tubes centered on the old holes. Used a router bit to open the hole from the outside to 1-1/4 and a holesaw from underneath to get it right at the deck end. Haven't put the metal 'liner' tubes in yet; waiting til the decks are done. Not sure if I got pics but will post if I find some.

[Oldboat]

Make sure the gap were rooted n block was not is filled in some how for Weigh and pounding will pull liner and hull togeather and cause leak. My brother in laws boat sunk in the keys many years ago when the fish box block rotted out there for flexing hull and liner togeather after a a day in ruff seas next morning sunk

[John3325]

The ones in mine are definitely brass (not bronze). They must have been replaced then. They held up all season this year, maybe I should just leave them for now. I'm not ripping up my deck or anything like that this year so I could be opening up a whole can of worms that I don't want to get into right now.

I thought the process would be as simple as knocking out the old and plastering with 5200 (or sealant of your choice) a new tube up the whole with the flange tool.

[Oldboat]

It is as simple as u said. If you think you will be rebuilding in the next few years I would leave them alone. I would pay attention to the fish box thru hull. If you trailer your boat u should be good for u will be there if u get a leaks.