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So after unwrapping my baby I discovered water laying on the inboard side of the Starboard ballast tunnel. Sponged it out and got about a gallon of water!
Boat has been tarp wrapped all winter. I raised the trailer jack as high as it goes and sponged out some more (slight depression in front of the battery compartment under stairs). I opened the ballast valve on the stern and it trickled for 15 minutes. I deduce there is a leak in either the ballast tank rear or in the inside of the starboard tunnel maybe from the pounding in high seas. Thought maybe filling the gap in the rear of the tank and under the sole alongside the tunnel w/ some kind of foam to seal. Don't know how rapidly it leaked, could have been all last summer. Any advice?

Hi!

We have been looking at some of the prior forum entries relating to the ballast tank and hull structure just to understand our vessel design.

When after storage water is found on the outboard sides of the ballast tunnels it appears the consensus has been to look for a window, fitting or chainplate that needs to be resealed.

Inboard of the ballast tunnels rules some but not all of that out.
Water is funny stuff in that it always seeks out even the smallest opportunity it seems to get inside a boat.....

May we ask a couple questions?
- Was there any indications that there was water or moisture on/in any of the central cabin interior surfaces?
- Was there any chance that a ceiling fitting or screw or pass through structure up hill of where you found the water could have worked loose or the sealant dried out that may have allowed water to slowly migrate in? (Even the best of tarps may have allowed water in underneath as some point or weather condition)
- Could it be possible that the water drained from the ballast tank is unrelated to the water found inboard of the ballast tunnels?

We’re not sure that going straight to applying a sealant foam would be advisable based on what we have read. It would seem that a more prudent approach would be to confirm in a positive manner where the water actually came from.

One method described doing a water ballast tank integrity check (if our boat trailer and tires are up to it and it can be done safely without damage to the boat or trailer) which is to use a hose to fill the ballast tank through the tank vent hole with water while it is on the trailer. Have all the hull access panels open ahead of time and look to see if any water re-accumulates where you found it. This may/may-not happen right away so be prepared to wait a while. A dusting of Talcum power or Flour are two of the more common “leak path” identifiers to help chase a leak back to its source.

If you can identify the actual source of the leak as being a particular location, wall or seam of the ballast tank system then you can apply an appropriate remedy. It’s one of those things that comes under the guidance of “it depends”.

Once you confirm it is actually a specific area let the forum know what you have found and provide pictures if you can via the “Add image to post” button at the lowere left border of the post portal.
We are sure that there are many members who are more than willing to help you appropriately resolve/repair what you discover (if the leak is actually coming from the ballast system).

Best of luck and good hunting!

Ballast tank leaks are EXTREMELY rare. I know of only one case and it was from poor resin application on one tiny spot.

Before attempting to seal anything, you really need to be certain where it's coming from. As mentioned above, water finds its way into places that can challenge locating the source. Even condensation can collect.

There are many methods to finding the source. Powder, dye etc.
If I thought it was in the ballast, I would fill the ballast with a hose and add dye. Look for dyed water infiltration.

Honestly, I doubt it's the ballast. Nuisance water is very common with these boats. Here is a thread with some tips to find the source.
https://macgregorsailors.com/forum/view ... 96#p349796

Please keep us posted what you find.

Leaving aside for the moment the questions of why your ballast tank had water in it when the boat was on the trailer...

Correct me if I'm misunderstanding your symptoms.

You found what ended up being about a gallon of water in the bilge near the ballast tank after the boat has been in storage all winter. You suspect that the water came from a leak in the tank while you were using it the previous summer. It's been under a tarp all winter. There was some small amount of water still in the ballast tank (trickled out).

Even in NY I don't see how water from last summer could still be in the bilge today. Hasn't there been enough time for it to have evaporated before any freezes and/or after the thaw?

I'm with Russ on this one. I'm only aware of the same single verified tank leak and it was a manufacturing mistake that was not hard to repair. Even that one was so small that it went years before anyone noticed and fixed it.

Getting a gallon of water in the bilge from rain or melting snow is not hard at all. You likely have a small leak somewhere topside or in the cockpit.

Slightly off-topic but since it was mentioned:

Leak detection is one reason for filling your tank on the trailer but filling the ballast tank, even partially, is a good way to weigh down your boat if a hurricane is coming your way. I've purposely "sunk" almost every boat I've owned on its trailer when a storm was expected. Be careful of overloading springs and tires.

Took me a bit, but here's the thread for the only confirmed ballast tank leak I can remember. http://www.macgregorsailors.com/forum/v ... hp?t=25843 There are lots of threads about suspected leaks, but this is the only one I know of that ever confirmed it was actually the ballast tank.

wgshaw was the owner on that thread. They said, "About 4 boat bucks to get it fixed". Removing the floor was not easy. Was there another confirmed case that was an easy fix?

Jeff

Russ and Be Free are both right in that ballast tank leaks are actually very very rare.

We are aware of possible 2 instances of a ballast system leak.
The one was a pinhole leak through a long torturous path due to minor inadequate resin layup from the factory that wasn’t noticed or found until a new owner conducted a ballast tank check on the trailer. The particular owner did a “YouTube” on it that showed a very tiny weepage that chased back to a corner void a couple of feet away. The fix, once the location of the weepage point was known was to inject active resin into the subsequent dried out leak path.

There are much more mundane reasons for the water you observed .....

Thanks for the responses! Snowy/rainy day today, will block up and add water to the bilge tomorrow. there was one instance last summer when I found a bit of water on the outboard side of the tunnel. Hope they're both related to another source other than the ballast.

Tip: dry everything up and then sprinkle flour around the suspected leak area.... then fill the ballast tank. If you don’t see any damp flour your leak isn’t from the tank. Now, with the flour still in place, use a garden hose to flood the usual areas where leaks occur, one at a time, checking carefully to see if the flour is dampened. You’ll soon find the culprit.

Filled the ballast tank, no leaks! Bone dry. Was loosing sleep thinking about that. Will now pursue all the usual suspects.

Great news!

I am very happy for you. I hope wherever you find it that it is easy to reach and even easier to fix.

Hip Hip Hooray!

That’s great news in that your ballast tank is sound! Celebrate a little as that is one big worry behind you!

We’re very happy for you!

In my time here I’ve heard of two instances of leaks. One from a really rough trailer ride, and one from drilling into the tank accidentally to mount battery downs.

Ix

AHA! Had wife fill the stern motor well w/ water while I squirmed into the back of the berth and stuck my hand along the well drain hose to find a massive leak. When winterizing I pour anti freeze into the sink till I see pink drain out of the stern thruhull. Apparently none of it made it into the well drain hose! So when I was happily scrubbing and hosing her down (the boat not the wife) water was draining into the bilge! Fixed w/ new hose. Galley - stern well drain system needs some re-thinking next fall.