Aft Sump Flooding!

[Michael Moradzadeh]

In this year's "Spinnaker cup" race, the wind was string and on the nose, so it turned out to be a bumpy upwind slog of about 90 miles.

Our J40 made it about 10 miles and retired.

Our excuse? A lot of water in the cabin.

We were heeled well to port, burying the rail, and slamming a lot. Crew noticed a couple inches of water standing in the port corners of the cabin.  I bailed out out, but it refilled quite quickly.  Time to quit!

My theory is that the water was coming in through the shower sump line.  Either siphoning or the entire assembly was below the waterline enough that the water could just flow in. 

 I will head back to boat this morning to freshwater rinse everything, turn on a dehumidifier, and eyeball the situation to see if my hypothesis holds.... water.

Michael

O2, 190 J40

[Tom Keffer]

Don't know about a J/40, but my J/42 will flood through the sink in the aft head when on a hard starboard tack. 

--
You received this message because you are subscribed to the Google Groups "J/4X Owner's Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to j4x-owners-gro...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CA%2BQsaPNpNLDYX4j_JWGXWHN6AhfXR%2BuChK8gWEafH%3DyYTn%3D1Pw%40mail.gmail.com.

[John Hope]

Same on a J-40. We close the thru-hulls in the forward and aft heads when we’re sail hard on the wind. 

John

Misty Rose

J-40 #80

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CAPq0zEC4kPQG-5nYHa78tqQMiuuZ2mfRv3uCSzCD36AT8gCjgg%40mail.gmail.com.

[Chris Leo]

I had this problem on one of my first cruises when I bought j/40 Cowbuoy in 2018. On a port tack, the cabin began filling with water from the aft. It turns out the starboard cockpit drain was cracked in its final turn towards the aft thru-hull. So water was freely flowing into the boat on that tack. 

I put a wooden plug in it and sailed on for the next 6 years like that, until I finally replaced it all in 2024. It’s just impossible to get back there, when I removed the aft water tank it finally created enough room to at least exist back there and get the job done.

On Sun, May 24, 2026 at 12:48 PM Tom Keffer <tke...@gmail.com> wrote:

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CAPq0zEC4kPQG-5nYHa78tqQMiuuZ2mfRv3uCSzCD36AT8gCjgg%40mail.gmail.com.

[Michael Moradzadeh]

That's interesting....  I believe my surveyor noted something like that and I had the boatyard deal with it.... I think.

Dang, now I gotta go check that too.

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CAJg-wYL5wB%2BNRyUFbRotfUK2Z3c9WfNXb3Z3VgEs5SKDqZQsdA%40mail.gmail.com.

[Jim Bordeaux]

When heeled hard to port, J40 can get flooding via the sink in the forward head.

Sent from my iPhone

On May 24, 2026, at 1:43 PM, Michael Moradzadeh <m...@yachtpc.com> wrote:



To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CA%2BQsaPOLgPc%3Dbat0%3Da2318Ff3yVVcbPZFDoMdAKFHrF2dWHBwg%40mail.gmail.com.

[Michael Moradzadeh]

aha.  did not look in the forward head.

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/40F7531C-8B35-4E89-B143-1D8C73F086E3%40gmail.com.

[Al Goethe]

Flooding through the forward sink is a pretty common problem I think. J/44 has it. I’m sure J/46 would have it, too, except Hamburg II (#31) has a check valve on the sink drain that prevents that. 

When heeling hard in heavy air it’s always better to have these seacocks closed. 

Al Goethe

On May 24, 2026, at 11:48, Tom Keffer <tke...@gmail.com> wrote:



To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CAPq0zEC4kPQG-5nYHa78tqQMiuuZ2mfRv3uCSzCD36AT8gCjgg%40mail.gmail.com.

[York.richardw]

MM-

On at least one 42, there was frequent siphoning of water back through the electric bilge pump hoses.   Although there was a loop, it was no where near high enough, and had no anti-siphon valve.

Worth a peek.

… Dick

On May 24, 2026, at 15:28, Al Goethe <ankg...@gmail.com> wrote:

Flooding through the forward sink is a pretty common problem I think. J/44 has it. I’m sure J/46 would have it, too, except Hamburg II (#31) has a check valve on the sink drain that prevents that. 

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/3E0222ED-31EB-4BBC-9812-4C6B8B7D6FA3%40gmail.com.

[Fred Hawes]

Gentlemen,

I want to thank the person that decided this was an appropriate topic for larger J boats. Twice, Anona (J-46 #15/35) has had water coming up thru the sole in the port side of the galley, while ocean racing in 4 foot chop. I have, until now, not figured it out, although I have replaced the aft 5 sole pieces in the main saloon, and the electric bilge pump and associated trigger switch. It sounds like the thru-hull to the aft sink might be the problem on a hard starboard beat. This has never happened in the bay.

Thanks guys,

Fred Hawes

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/40F7531C-8B35-4E89-B143-1D8C73F086E3%40gmail.com.

[David Jade]

We have had sea water come up through the aft sink drain once or twice and overflow on a rough passage. It seems the one-way valve in the drain lines occasionally acts just like one of those shaker-siphons. Our solution is to just close the seacock when it happens.

                                                                                                           

Hmm, now you got me thinking. Has anyone ever seen this bilge siphoning on a J/46?

 

We had an instance of a mysterious amount of salt water appearing in the bilge after a 4-day offshore passage and we haven’t been able to locate the source. It is not the usual water down the mast into the shower path as our mast boot does not leak even a drop nor does anything but rain water ever get inside the mast.

 

Siphoning from the bilge is about the only theory I’ve been able to come up with since we can find no evidence of a path that water took to get to the bilge. We have an anti-sipon valve on the loop in the forward closet but one thought now is that maybe it got fouled and allowed siphoning with a good amount of rolling and heel.

 

David             _/)

~~~~~~~~~~~~~~~~~~~~~

 

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/1047893830.2854477.1779660476770%40mail.yahoo.com.

[Michael Moradzadeh]

Yeah the lack of good anti-siphon is my prime suspect.

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/SA0PR03MB544930697DA1189452EB698AB30D2%40SA0PR03MB5449.namprd03.prod.outlook.com.

[Todd Stevens]

Well, one more possibility that I mentioned in another thread - 25 year old bilge-pump hose recently removed from my boat was brittle and easily cracked.  Considering that the through-hull is almost at the water line on the port side, any cracks toward that end could let water in when heeled.  Worth checking and/or replacing before that happens.  

My vented loop is found near centerline up in the top of the galley cabinet. Seems high enough for most occasions? 

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/SA0PR03MB544930697DA1189452EB698AB30D2%40SA0PR03MB5449.namprd03.prod.outlook.com.

[Dick York]

Todd ....  good point on the brittle hoses.  

I actually had to do a pan-pan from ARAGORN one night, at 2300.  Sailing very fast and water coming in the boat.  

The drain from the propane locker exits far aft, just above the waterline.  Of course it was below the waterline at 8 knots.  

The 22-year old drain hose was hit by an errant box not properly tied down, and the wear cracked the ancient hose.    Nice water intake in an almost invisible place.

Two aboard; I was able to divert to Pilot's Point easily. The crash pump worked its magic, and we (of course) took on no new water once tied to a dock.  

It took me two days of unpacking a loaded boat to find the bad hose.

I need to find all the old hoses and have them replaced on a regular basis.  I used to do that on the engine with a great mechanic.  But now we should be looking at all of them.

BTW, does anyone know the lifespan of a Propane gas hose? Anyone have an ABYC spec on this??

Thank You ... Dick York

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/A69446E2-9FA5-4E9C-A780-151361BC28BD%40me.com.

[Dennis Boyd]

ah you guys keep coming up with projects for me.    As part of the "return to glory" tour with "Jaywalker" I have been replacing hoses.    Initial all those with thur hulls valves (below waterline)  And then a few the surveyor pointed out.   I looked at the propane locker hose, a said meh, above water line.    rethinking that now.      However,   I have been thinking about the bilge pump.   Not the manual one, but the auto one from the bigle.    How do you get to that thru hull?    Is it behind the ice box?    

Dennis 

Jaywalker #6

J/42

[jmruzzi2]

Everyone, 

It's not a flooding issue, but Spada's aft sump float switch failed recently.  In replacing it and cleaning the icebox, I discovered that the icebox drain is also plumbed into the aft sump along with the aft shower pan.   That explains why the water in that sump was so nasty/greasy.

Joe

Sent from my Galaxy

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/89f5adba-bf37-4119-9559-3994d202ccacn%40googlegroups.com.

[Michael Moradzadeh]

Better than the bilge, I guess.  My sump has no float switch, but I think I will add one.  I'd also like a pump that does a better job of getting that last drop!

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/6a19b0ab.2e37fc6a.123b94.913a%40mx.google.com.

[Joseph Ruzzi]

Michael,

I'm not sure if the float switches were added by the previous owner of Spada, but both the forward and aft sumps have them.   On the DC electrical panel, there are the typical 2-position switches along with one for the bilge pump.  Just below that is a momentary contact switch that allows manual activation of the bilge pump.   I believe  the bilge pump is wired direct to the 12v bus, while the breaker just energizes the manual override switch.

Regards,

Joe

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CA%2BQsaPNd9xQW0c%2B4bD3eAYXYjcn7f6t5WhTtX4PoTsmjK6SDtg%40mail.gmail.com.

[Todd Stevens]

On Wild, the bilge pump is wired directly to the battery (fuse on the sub-panel). The forward and aft head sumps are scabbed on to the “fresh water pump” circuit breaker. All of the wires disappear into a big multi-conductor connector so you can’t trace them.  I’m slowly correcting that.  

Rather than getting a bigger breaker panel, I’m making branch circuits on a DIN rail inside the instrument cabinet.  

Sent from my iPad

On May 29, 2026, at 20:02, Joseph Ruzzi <jmru...@gmail.com> wrote:



To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CAMfi8Cw1M9ZXDxkP1re_p7PdDj%3D%3DMky9T89ombtR-Jw1VentEA%40mail.gmail.com.

[gale...@gmail.com]

Another place to check for aft sump flooding is the engine exhaust hose connection at the stern thru hull exhaust port. My exhaust hose had rotted at this connection causing water entering the aft sump on my J42.  Took a long time to finally diagnose the flooding source and a #$*@ to replace. I think I entered a thread on this before. 

Galen 

J42 Tango

[gale...@gmail.com]

I would also suggest checking out the Ultra Safety Systems float switch for your bilge pump.

Galen

[David Shapiro]

Hi Dick,

Regarding your question about the lifespan of propane gas hoses, I found some information from M.B. Sturgis Inc.

They recommend replacing propane hoses used in high-pressure applications every five years, noting that constant pressure build-up, UV exposure, and weather conditions all contribute to wear. They also emphasize that if a hose shows any signs of damage, it should be replaced immediately, and routine inspections are necessary for safety.

In aviation, we use a physical examination similar to Aeroquip and Stratoflex standards: if a hose is stiff, crackles when bent, or smells permeable (like a sanitation hose), it should be replaced. 10 years is typically the limit for aircraft fuel and oil lines unless they have teflon liners, which are considered lifetime but are much more expensive.

Best regards,

David Shapiro
SV Sandpiper
J/42, #32

Bridger Aviation Services, Inc.
Three Forks, MT

406-579-3166

--

[Todd Stevens]

Of course, propane supply lines are very low pressure.  The only high-pressure hose would be between the tank and the regulator.  If your regulator screws directly on to the tank, you don’t have one.  

Todd

--
You received this message because you are subscribed to the Google Groups "J/4X Owner's Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to j4x-owners-gro...@googlegroups.com.

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/CACrnMguMBVHXpWgtgLSEMD9VhdjmGrLoD6uKC78pw%3DOngcGyBg%40mail.gmail.com.

[York.richardw]

David-  Thank You … Dick 

On May 30, 2026, at 17:27, David Shapiro <dashap...@gmail.com> wrote:



[Global Movement Network]

Hello,

I'll add my two cents. When I got the boat (J40) it had cheap ribbed hoses for aft sump thru hull (and elsewhere). I had a port side leak at heel in the aft hanging locker from the degraded hose, since replaced. I've also had to rebed several above waterline thru hulls on the port side. They were leaking at heel. 

Hope you solve it. 

Fair winds,

James