As a follow-up .... are you sure that you are trying to turn it the right way? Every once in a while, I have to check myself!
Thru Hull Replacement?
- Thread starter Randall Schmidt
- Start date
The thru-hull is the fitting that actually goes through the hull. The valve attached to the thru-hull is called a seacock. FYI.
The original valves on the O'Days are just that, valves and not real seacocks. If the Marelon valve you reference is just screwed onto the through hull fitting and does not have a flange, then putting any serious lateral force on it to try to close the valve risks breaking it or the through hull fitting. Those valves are often not matched to the through hull threads (pipe thread valve, straight thread though hull) and end up only having a few threads engaged. I've replaced three of my valves with real bronze seacocks and thick fiberglass backing plates that are epoxied in place. The seacocks are rock solid with three screws bolting them to the hull along with the threaded through hull fitting. MaineSail has a great DIY instruction on this and I highly recommend you consider this if you plan to keep the boat. Not a huge cost but a bit time consuming. Also O'Day only used a 1/2" through hull for the engine cooling water. It is highly recommended to change this to 3/4" along with the hoses and fittings to your water pump and strainer (if you have one).
You don’t need any time for the sealant to cure before launching. In this video the crew at the yachtrigger install a new Marelon thru hull while the boat is in the water. It starts at 0:57…
Randall
Your image appears to show what looks like a Marelon valve. It has a triangular base. The base appears to be sitting on a fiberglass backing structure. If it is not closing, there is an issue inside the valve. One could try and resolve this while in the water, but I would be inclined to haul the boat for a proper inspection and ability to resolve the problem (even if it means installing a new through hull). The Marelon valve does not not look damaged. You may find sea life or flotsam in the through hull that is causing the issue. The Marelon valves need to be opened and closed occasionally for proper maintenance. If installed on a Marelon through hull you could be all good.
Being out of the water lets you inspect the entire through hull without water incursion into your boat.
Your image appears to show what looks like a Marelon valve. It has a triangular base. The base appears to be sitting on a fiberglass backing structure. If it is not closing, there is an issue inside the valve. One could try and resolve this while in the water, but I would be inclined to haul the boat for a proper inspection and ability to resolve the problem (even if it means installing a new through hull). The Marelon valve does not not look damaged. You may find sea life or flotsam in the through hull that is causing the issue. The Marelon valves need to be opened and closed occasionally for proper maintenance. If installed on a Marelon through hull you could be all good.
Being out of the water lets you inspect the entire through hull without water incursion into your boat.
I swear I was reading through this and was thinking "righty tighty, lefty loosey". Great minds think alike!
I had the same fitting on my Starwind 27. I never had difficulty opening and closing the valve, but I did have trouble keeping it cleared from eelgrass when floating mats of it would clog the intake. The problem was always the 90 degree bend was never easy to clear. I could remove the hose but still not be able to clear the clog easily from either the inside or the outside (under water). I suppose it is possible that you may have something wedged inside to prevent closing the handle. Otherwise, I still have a hard time understanding why a relatively new maralon fitting would be frozen. If I was really fixated on working on this, I might try removing that elbow just to see if there is something jambing the valve, even while water gushes into the boat. A bilge pump should be able to keep up with it for a while and you can always plug it closed when you feel like it.
But OTOH, this can easily wait until you have a better opportunity. The hose looks fine and the connection is double clamped. There doesn't appear to be any distress in the materials, so it should be safe. Many folks have a problem with those hose clamps although I have many of the same with no worries on my part. I look at them frequently and never have seen any sign of corrosion. Hose clamp failure due to corrosion seems to be the cause for a lot of concern.
I'm guessing there's something stuck in there, for sure. The 90 degree bend in that very small (half inch?) fitting is a great trap for detritus.
I just recently had a friend call me about diving the thru-hull for his AC (heat). It was collapsing his lines with vacuum pressure because the 90-degree bend after his thru-hull was clogged. He was able to close the 1"(ish) seacock (your situation isn't the same here, so don't do this!), remove the line, and clear the debris. No dive needed.
Snorkeling on the boat and looking at the thru-hull might give some answers, but since (I'm guessing) this thru-hull has a clam shell over it, you probably won't see much.
If it were my boat, I wouldn't be overly concerned right away, but there are some potential problems that could come up. Make sure the hose run is double clamped with SS clamps and secure. It looks like the outlet of the thru-hull is double clamped with quality Scandvik hose clamps, which is great. The first picture shows a hose at the top that is not double clamped, consider remedying that. One issue that you could potentially run into is that if the sea-strainer or valve/fitting actually gets clogged to the point where it can't pass water, which that 90" degree turn is kind of asking for, it's going to be harrowing to clear the clog since as soon as you clear the obstruction, water will be rushing into the boat with no way to turn it off.
Last thought: are you having overheating problems? If you are, that would suggest something is stuck in that valve. If you're not, that still doesn't mean that something isn't stuck in there, but would make me less concerned that an immediate problem is present. If you can't see an obstruction by diving on it, I think it would be wise to pull the boat. I'm thinking that if there is an obstruction in the valve body the chances of getting stranded due to an overheating problem in the future is fairly high.
I just recently had a friend call me about diving the thru-hull for his AC (heat). It was collapsing his lines with vacuum pressure because the 90-degree bend after his thru-hull was clogged. He was able to close the 1"(ish) seacock (your situation isn't the same here, so don't do this!), remove the line, and clear the debris. No dive needed.
Snorkeling on the boat and looking at the thru-hull might give some answers, but since (I'm guessing) this thru-hull has a clam shell over it, you probably won't see much.
If it were my boat, I wouldn't be overly concerned right away, but there are some potential problems that could come up. Make sure the hose run is double clamped with SS clamps and secure. It looks like the outlet of the thru-hull is double clamped with quality Scandvik hose clamps, which is great. The first picture shows a hose at the top that is not double clamped, consider remedying that. One issue that you could potentially run into is that if the sea-strainer or valve/fitting actually gets clogged to the point where it can't pass water, which that 90" degree turn is kind of asking for, it's going to be harrowing to clear the clog since as soon as you clear the obstruction, water will be rushing into the boat with no way to turn it off.
Last thought: are you having overheating problems? If you are, that would suggest something is stuck in that valve. If you're not, that still doesn't mean that something isn't stuck in there, but would make me less concerned that an immediate problem is present. If you can't see an obstruction by diving on it, I think it would be wise to pull the boat. I'm thinking that if there is an obstruction in the valve body the chances of getting stranded due to an overheating problem in the future is fairly high.
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If you can dive on it I suggest plugging it from the outside then unscrewing the elbow fitting so you can clean and grease it from inside.
Elbow fittings come in different functional designs. When needing a 90º turn for your fluid, seek out a "Full Flow 90º" fitting like this bronze threaded pipe to hose one by Groco.
