Thru Hull Replacement?

[Randall Schmidt]

I have a 1984 O-Day 28. When I purchased the boat in April 2016 I replaced the frozen and old thru hulls (3 of them). One with brass and one with marelon and the 3rd I'm not of. I neglected to regularly exercise the fittings. I just tried and the brass one (that controls sea water intake for head operation) works fine. The marelon fitting is frozen open. It controls inbound sea water for cooling the diesel engine. I'm afraid to force it open and risk a leak. I had the bottom planted 2 months ago so am not planning on hauling her out anytime soon. I'll try to force it open when she is on the hard and will be ready to replace it if needed. What. is the risk in me leaving this frozen open fitting in place? I did change the impeller in the recent spring and shut the valve off then with no problem. Why else would I need to shut this valve? I live in eastern NC where is warm enough in the winter that we use boats year round and do not winterize. Also is there any safe technique to try to open this valve while the boat is in the water? Does a change in temperature help at all?

 

[Siamese]

Mild confusion in your post. You say the valve is frozen open, but you're talking about trying to force it "open".

Can we assume it's open, and you're wondering if it's okay to leave it that way? And you're wondering if there's a safe way to exercise the valve? Please clarify.

With regard to whether you can leave it open while the boat is in the slip unattended, opinions will very. I leave mine open. Others will say they close their's every time they leave their boat. I suspect the vast majority of boaters leave them open all the time, but the argument will never be resolved.

 

[Don S/V ILLusion]

Marelon valves are infamous for sticking when not routinely used. My suggestion is don’t force it while in the water as they aren’t designed to withstand the shear stress. Bad things can happen. Make sure the hose and double clamps are intact and in good condition.

 

[Ralph Johnstone]

Can you provide a picture of the thru hull for the engine ? Given my druthers, I'd rather not leave the engine thru hull open as there is where the most shake, rattle and roll occurs.

Given a picture of the thru-hull, you "may" be able to heat the outside of the valve body in order to free the interior ball of the valve.

 

[jssailem]

you "may" be able to heat the outside of the valve body

He talks about the valve, identified as "MARELON" that is "stuck". If that is the case, I would think heating the plastic/nylon valve would be quite dangerous.

I would be inclined not to do anything till I could get the boat out of the water and safely work on the valve. But that is just the cautious me.

 

[Tally Ho]

I certainly would not force the Marelon valve…or put heat on it.

The danger of leaving it open obviously is that if something leaks, breaks, or lets water in and you have no way to shut off the water.

Photos would be helpful…just to see the condition of the valve and the installation/location.

A “short-haul” may be in order to try to excercize the valve…and replace if it won’t budge. Hard to believe a valve would seize up in less than a year.

Greg

 

[Crazy Dave Condon]

As a former Hunter dealer in North Carolina, I can understand it is expensive to haul out and I concur with @jssailem

When I sold boats, I use to supply a bag of balsa core cones in the event of water penetration for example a broken thru hull. Suggest you buy them just in case of a leak

Once I sold a Hunter 30 going on an inland lake in TN with only a long ramp that I used to launch this boat with my hydraulic trailer as there were no cranes or travel lift. I got a call that the boat was sinking which my customer was freaking out. He drilled into the hull below the water line and guess what, a geyser appeared. Anyway I told him to immediately put a balsa core cone into the hull and hammer it into that hull. Temp fix. It allowed me to get everything together with trailer and supplies as he was six hours away. Left that morning of call and pulled boat out. Started on repairs finishing the following day as it was summer time. Longer days. He paid twice. The first was my repair bill. The second was calming wife down for not calling me for advice

 

[Davidasailor26]

What. is the risk in me leaving this frozen open fitting in place? I did change the impeller in the recent spring and shut the valve off then with no problem. Why else would I need to shut this valve?

The valve is there to keep water out if something should fail- usually a hose or hose clamp. How old are the hoses off the seacocks? Are they all double clamped with quality clamps?

One with brass

Presumably (and hopefully) you mean bronze. Brass has no place on underwater fittings - the zinc corrodes away leaving the metal weak and failure prone.

 

[NYSail]

Also..... you said the other was brass? Or do you mean bronze? Brass is no good for salt water and will fail quickly.

And maybe the heat you put on the marlon fitting is hot water poured over the valve.... but as was said, I would not force it like I might try with a Groco Bronze fitting.

 

[Randall Schmidt]

Mild confusion in your post. You say the valve is frozen open, but you're talking about trying to force it "open".

Can we assume it's open, and you're wondering if it's okay to leave it that way? And you're wondering if there's a safe way to exercise the valve? Please clarify.

With regard to whether you can leave it open while the boat is in the slip unattended, opinions will very. I leave mine open. Others will say they close their's every time they leave their boat. I suspect the vast majority of boaters leave them open all the time, but the argument will never be resolved.

yes I misspoke, The valve is left open. I wish I had closed it periodically then it would still work,

 

[Randall Schmidt]

Marelon valves are infamous for sticking when not routinely used. My suggestion is don’t force it while in the water as they aren’t designed to withstand the shear stress. Bad things can happen. Make sure the hose and double clamps are intact and in good condition.

Seems right. I guess need to buy replacement thru-hulls and have them ready to install when she is out next time. While out I can try harder to force the valve to close and open. If I get it to flex will I know she is no-leaking while on the hard? Hate to find out on the way back into the water if the valve leaks. Maybe I need to just replace them. What a stupid bummer.

 

[Randall Schmidt]

Can you provide a picture of the thru hull for the engine ? Given my druthers, I'd rather not leave the engine thru hull open as there is where the most shake, rattle and roll occurs.

Given a picture of the thru-hull, you "may" be able to heat the outside of the valve body in order to free the interior ball of the valve.

View attachment 221138

I’ll try and share a photo. It is in a very tight spot. Guess you are think a heat gun to warm it up? this might damage the hoses. I have 3 thru hulls. One is stuck, one opens/closes and the other I need to test

 

[Randall Schmidt]

He talks about the valve, identified as "MARELON" that is "stuck". If that is the case, I would think heating the plastic/nylon valve would be quite dangerous.

I would be inclined not to do anything till I could get the boat out of the water and safely work on the valve. But that is just the cautious me.

I agree.

 

[Randall Schmidt]

I certainly would not force the Marelon valve…or put heat on it.

The danger of leaving it open obviously is that if something leaks, breaks, or lets water in and you have no way to shut off the water.

Photos would be helpful…just to see the condition of the valve and the installation/location.

A “short-haul” may be in order to try to excercize the valve…and replace if it won’t budge. Hard to believe a valve would seize up in less than a year.

Greg

It’s has been about 7 years since I replaced it. Maybe a year or 2 since I flexed it. A short haul… not a bad idea. Wouldn‘t I need to give the sealant plenty of time to set before splashing her? I imagine the haul out folks won‘t let me hold them up from using the launch area very long.

 

[Randall Schmidt]

The valve is there to keep water out if something should fail- usually a hose or hose clamp. How old are the hoses off the seacocks? Are they all double clamped with quality clamps?



Presumably (and hopefully) you mean bronze. Brass has no place on underwater fittings - the zinc corrodes away leaving the metal weak and failure prone.

I replaced the hoses and clamps when I replaced the thru hulls. This was about 7 years ago. I think I double clamped but will have to go recheck.

 

[Randall Schmidt]

As a former Hunter dealer in North Carolina, I can understand it is expensive to haul out and I concur with @jssailem

When I sold boats, I use to supply a bag of balsa core cones in the event of water penetration for example a broken thru hull. Suggest you buy them just in case of a leak

Once I sold a Hunter 30 going on an inland lake in TN with only a long ramp that I used to launch this boat with my hydraulic trailer as there were no cranes or travel lift. I got a call that the boat was sinking which my customer was freaking out. He drilled into the hull below the water line and guess what, a geyser appeared. Anyway I told him to immediately put a balsa core cone into the hull and hammer it into that hull. Temp fix. It allowed me to get everything together with trailer and supplies as he was six hours away. Left that morning of call and pulled boat out. Started on repairs finishing the following day as it was summer time. Longer days. He paid twice. The first was my repair bill. The second was calming wife down for not calling me for advice

Great idea. I purchased such cones when I bought the boat and had my maiden voyage before I replaced the thru-hulls. I have to look for those, make sure they are handy or buy new ones. I think the ones I had were made of rubber and tapered off so it could fit a range of hole sizes.

 

[Randall Schmidt]

The valve is there to keep water out if something should fail- usually a hose or hose clamp. How old are the hoses off the seacocks? Are they all double clamped with quality clamps?



Presumably (and hopefully) you mean bronze. Brass has no place on underwater fittings - the zinc corrodes away leaving the metal weak and failure prone.

Bronze, right.

 

[Scott T-Bird]

All my thru hulls are Marelon and have been on the boat since 1999. A few are very stiff to turn, but I do work them (by hand) despite how stiff they are. Yours is still a baby if it is from 2016 and I find it hard to believe that you can't turn the valve now after turning it just last spring (isn't that what you said?). If it's hard to get at, I suspect that you aren't able to get much force on it by hand. I wouldn't use any mechanical advantage, but I have a hard time believing that anybody could actually break off a relatively new handle by hand when you are in a poor position to even use much force to begin with. I suspect that you just aren't getting much power out of your effort. If you really feel the handle flexing, then, I would give up. But ... don't call me if you sink your boat!

 

[Straycat22296]

EVERYTIME I leave the boat for home, I close all my thru hull valves (Marelon) . I have never had any problems with the tru hulls sticking or being a problem. I also lube the valves during haul-out. I have owned boats for 45+ years and have done this proceedure on every boat. I have perfect peace of mind when I am away. I just feel it is a good habit to get into and it works for me.
I hope you find a solution to your problem.

 

[higgs]

If you replaced the hoses 7 years ago it is not likely they are just going to suddenly spring a leak. If you have been leaving the valve open in past years, what's the difference, now? None - unless you happen to be aboard when that hose fails.