Removing Corroded Seacocks and Thru-Hulls

[Beersmith]

Originally Posted by cat man do

I have Bronze through hulls at the moment, but I have seriously considered ditching them and glassing in a fibreglass tube with threaded end so as to attach the ball valve.

this is interesting. Have you or anyone else seen this done on a boat?

[donradcliffe]

Nice pictures, but way too much work. The easy way to remove the outside flange on a through-hull is to take a 4" angle grinder outside the boat and put it in the hole in the center of the thru-hull, holding the angle grinder perpendicular to the hull. Grind down far enough to cut through the flange-to-thruhull joint, slowly rotate 180 degrees, and you're done. It takes about 15-30 seconds per through-hull.

[Beersmith]

Originally Posted by donradcliffe

Nice pictures, but way too much work. The easy way to remove the outside flange on a through-hull is to take a 4" angle grinder outside the boat and put it in the hole in the center of the thru-hull, holding the angle grinder perpendicular to the hull. Grind down far enough to cut through the flange-to-thruhull joint, slowly rotate 180 degrees, and you're done. It takes about 15-30 seconds per through-hull.

good idea. I just didn't have the confidence in my grinder finesse to try something like that. I felt safer using the Dremel.

[cat man do]

Originally Posted by Beersmith

this is interesting. Have you or anyone else seen this done on a boat?

No
But it makes sense to me that it would be a better solution.
Fiberglass tube is lighter than the bronze
They are part of the boat
They are flush on the hull surface (no drag)
They dont go all manky

[gettinthere]

your fiberglass tube sounds like a sea chest. been around on powerboats for a long time

[sailvayu]

Pearson used to use FRP tubes on there production boats in the 60s-70s. Many still out there going fine. If you get a survey they most likely will be written up as they do not meet ABYC. Could be an insurance issue. Of course a broken tube sinking the boat could be an issue.

[cat man do]

Originally Posted by gettinthere

your fiberglass tube sounds like a sea chest. been around on powerboats for a long time

Nope, just a fibreglass tube though I have also considered a composite sea chest, 1 sea inlet in and several gated valves out to where required.

Now I have typed that out it makes even more sense, so that's what I will do

[David_Old_Jersey]

Originally Posted by Beersmith

good idea. I just didn't have the confidence in my grinder finesse to try something like that. I felt safer using the Dremel.

lol that strikes a chord

[Juniper]

I have a Pearson of that era, yes it does have the glass tubes, they are for the galley sink, the 'pit drains and molded to the hull ones for the deck drains, the head is still bronze valves as the head is in fact an after thought in the hull design, I've been told to remove the glass tubes by some, but noone that has them says anything about them, the one Pearson 35 I have read about sinking from thru-hull was hit by lightening and blew out the bronze, so what came with the boat I may leave as these need to stay open anyway, I am going to get some good plugs for them, the bronze will get replaced in kind as soon as I get her home, or go composting. I have other things to worry about too, I have a centerboard cable tube that is under the waterline and cannot have a valve, if that leaks there is no stopping it, so the only way a boat can't sink is if it's on land, but then you have a house, I'll make sure my hoses are good, and take the chance,

I would not try to glass in a threaded piece as glass is not that strong that way, if you do, think about using a large flange to get as much area as you can,

[ato]

Nice info! Thanks a lot!
Might be useful for this one...

[Maine Sail]

Originally Posted by donradcliffe

Nice pictures, but way too much work. The easy way to remove the outside flange on a through-hull is to take a 4" angle grinder outside the boat and put it in the hole in the center of the thru-hull, holding the angle grinder perpendicular to the hull. Grind down far enough to cut through the flange-to-thruhull joint, slowly rotate 180 degrees, and you're done. It takes about 15-30 seconds per through-hull.

Ditto! Have removed a lot of them in this fashion. Minimal to no damage to the fiberglass too..

[ironmike]

Thanks for the write-up. I have 6 sea-cocks to service and 5 of the 6 are the gate style with something frozen on each one. Time to replace. Was thinking of using marelon to avoid corrosion issues but now need to do some more research.

[redhead78]

I used the methods in Maines articles for 2 of mine, engine and depth transducer, worked out great. The engine intake groco,s tri-flange is my choice, you can always change up the valves if you want, good luck have fun...Red

[SabreKai]

Angle grinder with a cut off disk will cure all sorts of ills. I love that tool, and am never without mine.

Sabre

[nautical62]

Thanks for the informative post. I'm curious as to how people fill old holes that they won't be putting another through hull through.