Leak in watertank

I can only comment based on the pictures - you can see it better than I can. But in the pictures, it does certainly seem to have a "dip" - right after if makes it's first 90* turn.

Also, the hose seems to run downhill - that part is fine if the thru-hull fitting is lower in the hull. But if the thru-hull fitting is higher, then that's another issue that needs to be addressed.

It would be logical to think that it might fill just fine to 3/4 sometimes, and other times it doesn't. It all depends on where/how the water collects in the vent hose and if/how much the vent fitting is clogged. Even if you saw water spurting out of it, it could still be somewhat clogged. Meaning, when you fill the tank to 3/4 it may initially bulge, but then it starts to go back down as the air slowly escapes.
 
The only way I see the water tank being pressurized by a water hose filling from city water and 70psi would be a water system failure or mod that allows shore water into the tank. It would also require a failed shore water pressure regulator, the regular water fill cap be on, and a plugged tank vent at the same time.

When I fill my boat I stick the hose in the hole. That's a 5/8" dia stream of water flowing down a 1.5" dia hose. Even the fill hose would allow air to escape. When I over fill and water runs down the gunnel, that is what prevents the tank from pressurizing along with the vent hose. When I stop and the fill hose is full, the only extra pressure I might have is the head pressure of the water in the fill hose.
 
Well after better looking to the hose i have to say you are right. It goes up and down and when I overfill the tank and water comes up to vent the next time water stays in the hose. How to fix this? Or easy way: make sure no water is in hose and never overfill.
I also wonder why this middle wooden beam is so high on the left side: is it been lifted when the tank became a big balloon?

I wonder also if there is something that prevent water coming in the vent line and that, when you overfill the tank the water comes out only at the hole you use for filling the water.
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Well after better looking to the hose i have to say you are right. It goes up and down and when I overfill the tank and water comes up to vent the next time water stays in the hose. How to fix this? Or easy way: make sure no water is in hose and never overfill.
I also wonder why this middle wooden beam is so high on the left side: is it been lifted when the tank became a big balloon?

I wonder also if there is something that prevent water coming in the vent line and that, when you overfill the tank the water comes out only at the hole you use for filling the water.
View attachment 75060
I wouldn't worry about it. That vent hose looks original. The water system on your boat has been working for 25yrs.

Consider this....if that water was a blockage that created pressure during filling, wouldn't it also prevent the system from working properly when drawing out water while taking your shower?

I'm thinking the original purpose of the wooden brace was to simply help hold the tank in place, not to control bulges, even though it might be doing that also. I'd push that brace back down to it's original location and re-attach it.

Why does the tank bulge? I'd guess the tank walls are thin enough, lack rigidity, or maybe not supported uniformly on bottom and sides and when the tank is filled the weight/pressure inside is allowed to distort the tank shape.
 
Yes Woody, I agree with you. I wait till next week and look at the pb weld, if it sticks I leave it and push the brace down and re attach it.
I think also that when some water is in the vent line, this will be blown out when pressure exist by filling.

when I fill water i always do this on the same way you do.

the boat ain’t a new one so some things you have to keep in mind. Filing 3/4 is not a big problem. I will check regulair if the tank ain’t bulging when filling 3/4 and perhaps the watertank will hold for many years. Enjoy weekend everyone
 
Why does the tank bulge? I'd guess the tank walls are thin enough, lack rigidity, or maybe not supported uniformly on bottom and sides and when the tank is filled the weight/pressure inside is allowed to distort the tank shape.

Woody.....something is causing that tank to expand like a balloon. The expansion has already caused one crack. I'll respectfully disagree with the tank having no internal pressure when it is being filled. Sure air can come back up the fill hose if it isn't blocked by a heavy force of water coming in which is why I suggested he fill it slowly and only to the 3/4 mark to stop the tank from cracking in other places.
 
Today I checked the area and the jb weld sticked to the tank . I tried to scratch it off the tank with my nail but no succes so that’s good. Als i put the brace in position and attached it (with 1 screw though).

I still see some water coming from under the tank, it’s less but it’s there.
Maybe another leak somewhere or still remaining from the time we overfilled. Time will tell...

For now I keep my attention when i fill water again.

eveyone thanks for effort, thinking and advice.
 
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Well Guys, i cant sleep good when there is still some water and maybe someone had a good advice for me.

like i mentioned before, in front of the watertank there is a compartment and behind the watertank there is another where also the sump is located. In this case the compartment with the sump is te lowest compartment. Between this compartment and the watertank compartment there is a ‘wall’ . In the left/bottom corner there is a small hole were water can pass by. The compartment in front of the watertank is dry.

true the small hole is still coming very little water true. Maybe this is still water from the moment i overfilled the watertank but i am affraid there might by soms other leak in the watertank.

How can i know for sure?

i was thinking of putting some colour water in the tank and when i see some coloured water coming true the hole i know for sure there is a leak. But what kind of coloured water i use? We are still active in the boat and use a lot of water. Is this a good idea or are there other ways to check?
 
Some dark colored non toxic food coloring maybe?
 
Just a couple thoughts:

1) Pressurize the tank using 3 psi of air and see if it leaks down over a 5 minutes (no need to empty the tank of water). You have great access to cap off the fill, two feed ports and the vent. That is the only sure way to test the integrity of the tank.

2) To get that tank out ......would require cutting a fairly large hole in the flooring above. I'm not sure I would do that if it had a very small water leak. I have not replaced a water tank you your model but I have on several other SR models. It is a mixed bag. I have had to cut out 75 gallon tanks and install 40 gallon tanks just to avoid pulling the engines on some models. On a Four Winns recently, the Waste system tank under the salon deck (which is structural on that boat) cracked and was completely inaccessible. In that case ....it was easier to relocate the tank.
 
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When I pressurize the tank and after a while i see some water true the small hole (actually it is not a hole but rather one. wood rot piece in the corner of the wall) I still don’t know if it’s ‘old’ water or water from another tank leak. That’s why i was thinking making the water in the tank with a colour.

I found some pictures on internet of a guy that replaces his watertank on a 500. A lot of work :( . The guestroom wall has to be removed and so much more. But I know myself. If there is a leak it has to be fixed. I want a dry boat.
 
Just looked in the compartment in front and this time I also touched the carpet and the carpet was wet.
The carpet is glued to the floor so theoretical the water could also come from a compartment in front of that. But I can’t access anything in front. On a higher point in front of that is the airconditioning installed.

Really have to do colour test to exclude options.
 
That forward compartment is pretty much sealed at the bottom. We had water getting in there a while back. It turned out to be forward AC drain clogged, cleared the line, no more water.
 
Tx for that input bahama, gonna check that also as well as the anchor compartment.

funny thing is that when the boat arrived in the Netherlands in august I planned to build a bowthruster that we already bought. At arrival we discovered a leak in hydraulic system from the swimmingplatform. Al cilinders were leaks and weak seals, cost me a small week to repair (after repair 1 cilinder the next one leaked and another day passed). Then we really wanted to go in the water and we agreed to build the bowthruster in the winter.
What you would think if I build the bowthruster and see water in that compartment? Hahaha do you think it’s a small leak in the tank or maybe that the water comes from above or that you made a mistake building the bowthruster ?
For sure I let the boat been lifted out of the water.....
 
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Here is what I found out and ended up replacing the water tank on my old 400DA. The vent is quite a bit higher than the tank top so when the tank is filled until water comes out of the vent if polyethylene it will bulge out. It's that bulging that puts a lot of stress on corners and that is where cracks tend to occur. The 400DA has an L shaped tank and many fail on the inside of the L corner however cracks are not unique to these tanks. I ordered directly from Dura-Cast then drove over and picked it up; when over there I talked to them about repair. There is no way to repair the tanks unless you can do a "friction weld" repair like when they install a port in the tank; there is no adhesive that will work with the material. Still, he said, the corners (where mine was cracked) are the highest stressed areas and the friction weld would be a temporary fix. He reiterated to not overfill the tank.....
Tom
 
As much as it takes forever, I fill my tank with pretty low pressure from the hose.

No way the vent is releasing that incoming pressure as fast as it’s building and stressing it repeatedly can’t help.

I get it going and walk away. It might take half an hour to fill, but that’s OK with me.
 
Today i took out the carpet in the front compartment and as i expected a hole/crack in the back and in the front.
I dried the whole area and what happend: water came out on both sides. I was hoping that only water came out from the front but.....

I made misses happy to tell her the whole matras etc had to be removed to check everything. Airco no leak but the anti-sound foam was completly pulverized in a line to the top, under the anchor compartment.

Dropped anchor in the water and the outlet hole was clogged and some cracks at the bottom next to outlet. By notice the pulverized foam this problem is existing for many years. The last few weeks its raining a lot in the Netherlands as it does today. I saw a lot of drops falling from different issues in the anchor compartment. Normally nothing to worry about when water leave the outlet. I used a marine sealend for the cracks, maybe in a dry period i remove the sealand and do a couple of layers epoxy.

The other side of the ‘bowthruster’ compartment worries me a lot and makes me very unhappy by thinking of an extra leak in the watertank. I spoke a lot of companies and everybody tells me the same that its impossible to repair the tank from inside. When you can’t reach/see the crack you can’t fix it.
I put some paper towels on both sides and gonna check the compartment many times to see what happens.

The previous owner told us to fill the tank half. We didn’t payed that much attention at that point and didn’t understood what he was explaining in German language. For 100% sure he didn’t mentioned that there is a watertank leak. But why fill the tank half and not explaining why?
There were plenty clues that there is an issue somewhere. unfortunately I discovered them after the transfer of the boat.
Looks to me like a hidden defect and this gives me a bad feeling.....
 
Marc,

Your boat is 25 years old.....it is quite reasonable to have problems like this. Many of us on CSR suffer from Obsessive Compulsive Disorder (OCD) and worry about things that are not worthy of the time and emotions we give them.

If you were concerned about the engines/transmissions and hull.....those things are worthy. The water tank isn't. You can cut it out and replace it which is a few days work. Nothing short of that is going to fix the tank. You also have options such as relocating the tank and using a smaller tank with a watermaker (desalination device).

I wouldn't extend the lack of previous owner's disclosure around the water tank to the rest of the boat.
 
Well John, i asked the previous owner (after the transfer) to tell me everything, no mather what but everything should be good etc. Since the day the boat arrived we discovered issue after issue.

-First we had all cilinders from the swimingplatform (everyday 1).
-Second a big leak on BB side masterbedroom caused by the navigation light. This leak existed so long that a wooden brace that is around the length from the boat as a stut for the ‘bumper’ was completly rotten away over 1,5 meter. True every screw it leaked water. Cost me several days of investigation and finding
-Third: on our first trip after leaving berth I had no stearing. leak in steeringcilinder, 2 special seals were not standard size...two weeks later fixed.
-fourth: 1 thing the owner did mentioned was the vacuflush toilet in guestroom the 2 big seals in toilet has to be renewed. Ok, I changed them but pump keeps running every 30 min. Another day I changed the duckbills and found out i needed 4 duckbills, another day I changed the other 2 duckbills, pump now every 10 minutes. Then I changed on another day the vacuumtank switch and nothing improved :(. Then on another day I removed complete toilet en found another 2 o rings from an ax where you flush. Again no luck. Then on another day again i removed the toilet en at the bottom near de funnel I kit everything with marine sealand and yes finally repaired.
-fifth: actually the first and biggest problem: the boat cover. They told me with a small repair it will be ok. What happens: about 13 zippers where broken and unfixable. A sailmaker spend 3 days to sew all zippers to eachother and fix all visible holes in the canvas. This was done while the boat was on transport to the Netherlands. Then when the boat arrived I replaced the cover and while doing this..scratch another big hole, then when i leaned at the cover ..scratch another big leak. Oh my god I could almost cry at that moment. Our Harbour sailmaker was completly full with work but they planned us because the urgent need. The front cover is made and last Monday they make malls for the rear and till it’s finally finished we are surrounded with buckets to catch the water from the rain.
Sixt: when we were in Koper Slovenië waiting for the transport the first few days were days from bilge alarms. Every time the hose attached to the boiler came lose. The problem was that they used a home/garden hose attached to the hot outlet of the boiler, everytime the boiler gots his heat the hose melded and popped off. Lol this was the beginning of the water leak Sea Ray 500.

the small things that also appeared I don’t bother you hahaha.

but the engines runs great. i saw some small leaks where hoses and pipes attached to the motor. (Detroit’s sweat). Big maintenance I will do in feb/march. no worry about the engines.

anyway we are still optimistic and happy but sometimes......*$|@#%5§£
 
Marc,

Did you have a Survey done on the boat before you bought it? In the US we "trust but verify" previous owner stories with Survey facts. Survey's usually provide a pretty clear professional view of the issues that you have recently experienced with an idea of how much they would cost to repair. That way ....there are fewer surprises.

The previous owner sounds like a person who just ignored things instead of fixing them properly. The result is that you get the privilege of making sure it is done right so that you can enjoy the boat. It does get better with everything you repair.
 

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