To remove or not to remove that is the question

[Lucy Lu]

Buying my first boat and although I have some knowledge and experience of things aquatic, I have a question. The boat I have been looking at requires some work, all of which I believe is within my abilities to carry out. I have looked her over and over and over and there is nothing I see that I cannot put right myself. However, there is a through hull fitting which is obviously no longer used as it has nothing attached to it inside the hull. It is a fairly large diameter ball valve and I cannot see a useful purpose for it still being in situ. It is pretty much on or very near the waterline and has no protection other than it is closed. Question, can it be capped, should it be removed, can I safely leave it in situ. If I remove it, it will involve a complete repaint of the hull so if I can get away with not doing so, I would prefer it. Im new to this game so no arrogant replies please.

[Pete7]

What do you think it used to do? large bilge pump perhaps and do you have sufficient existing holes not to need it or are not willing to add an extra one.

Is the boat out of the water at the moment?

Pete

[Lucy Lu]

Yes she is out of the water, I can't think what the fitting would have been connected to, it is about midships, well away from anything visible. The heads is well forward of the fitting, the galley well aft and the engine even farther aft. My concern is twofold. Its a fairly large diameter ball valve, there is nothing to keep the hull watertight except the ball valve is closed. Common sense tells me to remove it but that will involve glassing it over which in turn will involve repainting the entire hull. Is there a way to cap it or should I bite the bullet, remove it, glass the hole over and repaint the hull. Incidentally, the boat is 54 years old, everything is built like there is no tomorrow. you could throw a mooring line for the QE2 around any of her cleats or fittings and they would hold, so she i not some flimsy production boat.

[SailFastTri]

“pretty much on or very near the waterline” and “fairly large diameter” are vague, and specifics could make a difference.
If below the waterline, or above, makes a very big difference. What is the condition of the valve? Does it turn easily? Is it a proper marine bronze, or maralon, or some less suitable material? If bronze, if you scratch the mushroom head outside it does it look pink or yellow/copper-like? (Pink is bad, indicates electrolysis and needs replacement). If white nylon or non-marine metal such as brass it needs removal or replacement.
If it’s in good condition and removal means repainting the entire boat I’d leave it and cap it. If in poor condition I’d replace it. If you can remove it without the major repainting I’d do that and fiberglass patch the hole, but keep in mind a proper patch requires tapered grinding and feathering in layers of glass over a larger area.
PS - congrats on your new adventure. Wishing you luck and enjoyment. Take lots of courses. Start with the US Power Sqadrons general courses - contact your local squadron. https://www.usps.org/

[Lucy Lu]

Having photographed the fitting from outside the boat, it is bang on the waterline as far as I can tell with the boat out of the water. I have tested the flange for dezincification and there is none. I could remove it but would prefer not to as this would mean a fairly large patch 6/8 inches and that would require repainting the entire hull. which I would prefer to avoid if poss. I have looked for any suggested ways of capping the fitting but thus far have found none. The boat is 54 years old, all the fitting were nicked from the Queen Mary and appear capable of being installed on a WW2 battleship, so although old, everything is of good old fashioned quality.

[SailFastTri]

Originally Posted by Lucy Lu

Having photographed the fitting from outside the boat, it is bang on the waterline as far as I can tell with the boat out of the water. I have tested the flange for dezincification and there is none. I could remove it but would prefer not to as this would mean a fairly large patch 6/8 inches and that would require repainting the entire hull. which I would prefer to avoid if poss. I have looked for any suggested ways of capping the fitting but thus far have found none. The boat is 54 years old, all the fitting were nicked from the Queen Mary and appear capable of being installed on a WW2 battleship, so although old, everything is of good old fashioned quality.

Then I’d leave it and add a tail fitting (nipple) on the inside with a cap to close it for added safety.

[Bowdrie]

No more than a guess, but a 54-year-old boat could reasonably have had some of its interior reconfigured.
The valve/thru hull in question might have been a galley sink drain, or perhaps there was one of those big diaphram manual bilge pumps installed amidships under a floorboard, that the outlet of the pump ran to.
Pumps such as the "Edson" "gallon a stroke" with a 12" diaphragm used to be quite common on older boats.

[Lucy Lu]

Thanks for your feedback, I will explore your suggestion and see whats about.

[Lucy Lu]

Thaks guys, I will look into it

[peghall]

The boat has a toilet...does it also have a waste holding tank? If so, where is it relative to the location of that thru-hull. 'Cuz I'm thinking it might have been used to dump the tank at sea. Or maybe to flush the toilet directly overboard.





--Peggie

[Seafarer7]

I’ve found that unused well-installed thru hulls like that can come in very useful much later down the line for installing additional equipment such as air conditioners, water maker, extra bilge pumps, generator, and the like.

If it’s well installed, you can simply attach a double-clamped short hose that exits above the water line for extra peace of mind, and then let it be for now, until some future date when the need calls.

[wingssail]

Originally Posted by Lucy Lu

Yes she is out of the water, I can't think what the fitting would have been connected to, it is about midships, well away from anything visible. The heads is well forward of the fitting, the galley well aft and the engine even farther aft. My concern is twofold. Its a fairly large diameter ball valve, there is nothing to keep the hull watertight except the ball valve is closed. Common sense tells me to remove it but that will involve glassing it over which in turn will involve repainting the entire hull. Is there a way to cap it or should I bite the bullet, remove it, glass the hole over and repaint the hull. Incidentally, the boat is 54 years old, everything is built like there is no tomorrow. you could throw a mooring line for the QE2 around any of her cleats or fittings and they would hold, so she i not some flimsy production boat.

I don't see any justification for repainting the entire hull just because you have removed and repaired a useless through hull fitting.

Of course you could cap the inboard end of the ball valve and just leave it. But I, being somewhat of a purist, would remove the whole through-hull fitting and re-glass over the hole (following best practices for the repair.) Then prime and paint that repair. You can leave the rest of the hull alone.

[Scubaseas]

Originally Posted by Seafarer7

I’ve found that unused well-installed thru hulls like that can come in very useful much later down the line for installing additional equipment such as air conditioners, water maker, extra bilge pumps, generator, and the like.

If it’s well installed, you can simply attach a double-clamped short hose that exits above the water line for extra peace of mind, and then let it be for now, until some future date when the need calls.

X2 on this. Sound advice. If you really want to remove it glass from the inside and only leave the "hole" on the outside to fair and paint. You should be able to match it close enough for a 5/5 test. 5' or 5MPH. anything more you can't even see it. Or do a different color, add tons more around the boat hull and change the name to Bonte Koe

[Tin Tin]

If the hose tail is a screw in fitting to the ball valve and it can be undone, then the appropriate cap can be screwed in with sealing tape. If the barb tail is immovable then as others have posted just add a hose that can have a plug inserted at the other end, not really that big a deal if it is in good condition and you may find you need a through hull for some other purpose down the track.

[Uncle Bob]

Originally Posted by Tin Tin

If the hose tail is a screw in fitting to the ball valve and it can be undone, then the appropriate cap can be screwed in with sealing tape. If the barb tail is immovable then as others have posted just add a hose that can have a plug inserted at the other end, not really that big a deal if it is in good condition and you may find you need a through hull for some other purpose down the track.

^^^^^^
This, a simple bronze plug of the appropriate size is all you need.