Hi all, I'm quite new to sailboat owning, and am just starting out on a Grampian 26' at a live-aboard marina. We took the old broken toilet out today to replace with MSD potty, and found out that the fitting for the through-hull (the one we don't need anymore) is super corroded, so much so that the top snapped off when we were cutting the old house. The valve seems to still be working, in so far that there is no water coming in. I'm pretty sketched out by it though and also supposed to go out of town for a week soon. Any ideas for fixes that don't involve a haul-out, etc. just yet? Or advice for how serious it is?
What to do about this corroded through-hull fitting?
- Thread starter saltyfriends
- Start date
I'd replace it or remove it and glass over the hole. Both jobs require the boat to be hauled.
As long as no one touches it or something heavy slides into it I think you're okay to leave the boat alone till you can get a repair organized. I mean look what you had to do to break it, using the leverage of the pipe and hose.
But, if you're going to worry about it all weekend anyway, try bracing the through hull on the inside with a few blocks or foam or wood and some duct tape. If you can go under the boat you can insert a wooden plug into external hole and seal it with a polysulfide sealant like "BoatLife - Life Calk" or Sikaflex 295. The clerk at the store can help. The polyurethane sealant/adhesives like 3M 5200 and 4200(fast cure) will work well, but are more difficult to remove in case you're considering a more permanent repair later, when the boat's out of the water (i.e. fiberglass). There are others, I'm just suggesting those I have experience with.
Good Luck, have fun on the weekend and don't fret.
But, if you're going to worry about it all weekend anyway, try bracing the through hull on the inside with a few blocks or foam or wood and some duct tape. If you can go under the boat you can insert a wooden plug into external hole and seal it with a polysulfide sealant like "BoatLife - Life Calk" or Sikaflex 295. The clerk at the store can help. The polyurethane sealant/adhesives like 3M 5200 and 4200(fast cure) will work well, but are more difficult to remove in case you're considering a more permanent repair later, when the boat's out of the water (i.e. fiberglass). There are others, I'm just suggesting those I have experience with.
Good Luck, have fun on the weekend and don't fret.
Great example of why you should always close thru hull when leaving the boat!
But in this case, if the boat is in the water…DONT TOUCH that valve. It looks like it will self-destruct if you mess with it.
Best thing to do is to haul the boat and replace the thru hulls (all of them if they all look like this). Or, if you are not going to use this one ever again, then glass it over and eliminate the hole in the boat.
Greg
But in this case, if the boat is in the water…DONT TOUCH that valve. It looks like it will self-destruct if you mess with it.
Best thing to do is to haul the boat and replace the thru hulls (all of them if they all look like this). Or, if you are not going to use this one ever again, then glass it over and eliminate the hole in the boat.
Greg
My exact thought!
If you are not planning a haul out very soon, drive an appropriately sized wooden plug into the thru hull fitting from the bottom of the boat. You can do it yourself or hire a diver. Initial friction & the plug swelling in water will keep it in place. Based on the appearances of the snapped fitting & the existing valve, I wouldn’t advise trying to put a plug into the valve from inside the boat. on haul out, I would replace the thru hull fitting & put a bronze cap or plug on it in the event that you want to revert back to a marine head in future. Probably should plan on replacing all thru hull assemblies & hoses.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,352
Based on the image of the hose and the snapped off report, It appears that the valve corrosion is at the near to failure status. It happens when the zinc in the bronze degrades at a molecular level. It leave the bronze looking pink.
In comparison you could look at the valve like a tire on your truck. You can see a nail in the tire, but at the moment the air is not leaking. If you had to go away for a week would you leave the truck sitting in the driveway or take the tire off the truck and carry the tire to a shop for repair.
Making sure your bilge pump is working on automatic would buy you some time if the leak was small. Putting a plug in the hole as @kloudie1 suggest would certainly delay the problem. You may find other issues appear.
It is the nature of boats. Sometimes they demand immediate correction to a problem. I can attest that a little leak is no fun.
Hmm how do you mean bracing it? I'm hesitant to touch the inside parts at all, I feel like not touching it is my best bet till haul-out. I'm considering cancelling my week away to deal with it...
For the external wooden bung: can I insert this without 'messing with' the valve? And can I seal it while it's below the waterline?
Would you recommend putting a bung through the outside while I figure out the repair, or do you think that could make the problem somehow worse?
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,352
The Bung fitted into the outside would be the only way you could temporarily stop the inflow of water without removing the internal valve. If you were on the boat and the valve broke, you would put the bung in the hole where the valve is. Turn on a bilge pump and head for the closest place to pull the boat out of the water. If you could not get to a haulout, your next best option would be to get to shallow water, where you could beach the boat to stop it from sinking.
The issue is that we have no idea about the condition of your hull or the through-hull opening. You could "pound" the bung into the through-hull, and it could crack the hull or split the corroded through-hull and cause greater damage.
This is an issue requiring on-site inspection and resolution. A problem that can only be safely done when the boat is hauled out.
I would haul the boat and resolve the through-hull issue. A valve I thought was good fell apart in my hand when I tried to remove it (I was hauled out at the time).
Picture of the valve before removal
This is a picture of the broken valve when I tried to turn it by hand to remove it from the through-hull.
Note in this image, you can see that the through-hull was still solid (the valve is being supported by the through-hull). The valve had corroded from the inside. When I opened or closed the valve, it worked smoothly.
The issue is that we have no idea about the condition of your hull or the through-hull opening. You could "pound" the bung into the through-hull, and it could crack the hull or split the corroded through-hull and cause greater damage.
This is an issue requiring on-site inspection and resolution. A problem that can only be safely done when the boat is hauled out.
I would haul the boat and resolve the through-hull issue. A valve I thought was good fell apart in my hand when I tried to remove it (I was hauled out at the time).
Picture of the valve before removal
This is a picture of the broken valve when I tried to turn it by hand to remove it from the through-hull.
Note in this image, you can see that the through-hull was still solid (the valve is being supported by the through-hull). The valve had corroded from the inside. When I opened or closed the valve, it worked smoothly.
I'd consider fiberglassing a PVC pipe or cap around the valve from the inside so if it does leak, it'll provide a reasonable seal. Use one that's oversized so there's enough surrounding area to install a backing plate when you replace the valve without grinding
There is no “somewhat worse” than about to fall apart. The only question is similar to what Clint Eastwood asked in Dirty Harry. “Well, do ya punk?”
In order to drive a bung into the through hull from the outside, it will be necessary to apply some force to the through hull. Applying that force will jeopardize the thru hull to an unknown degree raising the probability of it failing. Leave it alone, don't go any where with the boat that you can't walk back to car. Its the middle of August, hauling the boat early will keep it afloat and give you more time to effect a good repair.
Yes, I think pushing a bung in from the outside is the way to buy some time.
Greg
Or this….
But if the skin fitting failed while driving in the bung, I would just drive the bung in further…
Best case scenario, haul out and replace it.
Greg