J/30 Class Association

Dewatering Aft Bilge - Need Advice

Posted By: Rhapsody #348

Dewatering Aft Bilge - Need Advice - 02/22/06 10:53 PM

I've read much of the history in this newsgroup on the inability of the aft section of the bilge (behind the vermiculite) to drain. I know Rhapsody has some serious moisture (standing water?) there but can't readily get to it. I saw one post that indicated their boat has a 3" inspection port cut just in front of the engine with a screw plate to gain access. I'm thinking I could cut a hole there, install a screw plate and then put a temporary bilge pump hose to pump it dry. I may be able to get a rag down there on a flexible bilge picker to really dry it out. Any experience from those out there who may have dealt with this issue?

I'm looking for something like - "don't do it, it's a waste of time.... or - yeah, I did that and it worked great!"

Thanks,
Bill
Rhapsody - #348
Posted By: LChristy

Re: Dewatering Aft Bilge - Need Advice - 03/01/06 07:30 PM

Bill -
Why doesn't this water just drain into your bilge?
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 03/01/06 09:33 PM

Quote
Originally posted by LChristy:
Bill -
Why doesn't this water just drain into your bilge?


This is the age old problem discussed in previous posts. Apparently the J/30 design contains a molded section filled with vermiculite in the area between the removable deck board (main center bilge) and the molded area under the ladder that supports the Yanmar. If you get water under that area, it does not freely drain forward to the main bilge section where the bilge pump is. It is not readily accessible unless you are a contortionist and can reach forward using the cutouts in the molded section below the engine mounts adjacent to the engine oil pan.
Posted By: rdpierce

Re: Dewatering Aft Bilge - Need Advice - 03/02/06 07:48 PM

*grin* I've tried being such a contortionist, and have the fiberglass-abraded arms to prove it!

Every winter I stick a flexible hose through the engine mount cutouts and use my oil pump to drain it as best as I can.

OK, another question while we are on the subject....

There are two limber holes on the outboard ends of the track that holds the companionway steps. What happens to water that reaches those holes? Does it go to that undrainable void below the Yanmar? (Which would make no sense; why add limber holes if they can't drain anywhere useful?) Or did they do something special to get around the vermiculite problem?
Posted By: LChristy

Re: Dewatering Aft Bilge - Need Advice - 03/07/06 04:23 PM

I have an opening at the back of my bilge that appears to connect to and drain the area under the engine. The hose for the bilge pump comes through here and goes into the bilge. Water drains ouot all the time. I take it you do not have this opening???
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 03/07/06 04:35 PM

Quote
...The hose for the bilge pump comes through here and goes into the bilge. Water drains out all the time. I take it you do not have this opening???[/B]


Mine just weeps a little water. Sticking a coat hanger through the small diameter hole (less then 1/4") does nothing. I'll get a 10" diam pool of water in front of the flat portion before it drains into the keel bildge well, then it stops. If I sponge up the puddle, it will be back in 20 minutes. Almost like there is a moisture sensor and feeback loop!
Posted By: rdpierce

Re: Dewatering Aft Bilge - Need Advice - 03/09/06 03:23 PM

Larry, it looks to me that the big corrugated hose for the Whale Gusher is running through solid filler at the aft end of the bilge with no space on either side. But yeah, if that hose runs back through the void under the engine, then it would follow that any space on either side of it would allow that void to drain.

I can try poking wires around on either side to see if I can dislodge anything.

I think I also read of someone ripping out that hose and replacing it with a smaller diameter, which results in room for the engine bilge to drain. Mine has some air leaks at the end near the bilge, so unless the bilge is completely flooded, my Whale Gusher won't do a darn bit of good. I may consider replacing that hose at the same time.
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 03/13/06 03:06 AM

Quote
...I saw one post that indicated their boat has a 3" inspection port cut just in front of the engine with a screw plate to gain access. I'm thinking I could cut a hole there, install a screw plate and then put a temporary bilge pump hose to pump it dry.

I'm looking for something like - "don't do it, it's a waste of time.... or - yeah, I did that and it worked great!"
[/B]


Ok - I cut a 2 " diam hole in the glass just in front of the Yanmar. Unfortunately it's dry there so that's not where the water is coming from. I put in an old fuel filler deck connection to plug up the hole. If anyone is interested, I can send the picture.

Bill
Rhapsody - #348
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/07/06 03:23 PM

Howdy,

I purchased a J/30 last summer that I'm in the process of recoring and generally rebuilding. I'm impressed by the collaboration and generous community on the J/30 class site, so I thought I'd share some of my story with some point specifically regarding the vermiculite in the bilge issue.

My boat suffers from several big problems:

1) The core below the waterline on the starboard side is wet 3/4 of the way up to the waterline
2) The core on the port side is wet around the keel sump for about 2' surrounding the keel
3) The vermiculite under the floor was soaked with black mold and diesel
4) The foam under the ice box has hydrolyzed in spots and very moldy
5) The boat smelled nasty

Sounds pretty grim, but my repairs are going nicely and I expect the boat to be beautiful, strong and in the water this June. I'm taking steps to do a pretty radical renovation, but in the end it will save time on my repairs (no pussyfooting around, or tactical use of self-delusion) and make the boat easier to maintain and inspect in the future. In any case, I thought I would share my findings under the floor since their is some question about what's going on in there.

I am doing much of my recoring from the inside since it will minimize the amount of fairing that I'll have to do on the completed hull and because I had to eradicate the 'rotten old boat smell' coming out of the floor of this boat. To accomplish this, I have cut the old floor out and stripped out the vermiculite under it. The floor itself was teak and holly on top of a 3/8 cored fiberglass laminate floor. While my T&H was beautiful, the floor/vermiculite under it was a nightmare.

When these boats were manufactured, the molded interior was bonded to the hull using either vermiculite or shredded chop strand, either of which were basically mixed with polyester resin to form a bondable 'peanut butter'. Several areas are bonded with chop strand for strength and durability - under the mast step, under the engine, under the vertical side of the quarterberth units. This material does not absorb water and is bulletproof. Vermiculite was used generously elsewhere, especially under the floor, which is basically solid vermiculite between the roving of the hull and the floor laminate. The vermiculite sends my Aquant water meter right into the red, its soggy and in spots, brittle. I chipped it out pretty quickly with a pneumatic impact hammer.

As you know the bilge pump hose was laid permanently in this vermiculite down the center seam of the boat. About 3 ft back from the keel sump there is a low point where water collects in the solid glass center seam. Unfortunately, as soon as this hose breaks down, pumping out has the effect of pumping water into the vermiculite. In my boat, it also appears that diesel had collected in this area, probably as a result of a spill during a filter change. When I opened up this area, it was ugly - full of black mold and a greasy wet collection of water and vermiculite... Yikes.

The previous owner had obviously figured out that the pump hose was leaking and had threaded a smaller diameter reinforced hose through the old hose and into the bilge (which I see was suggested in this forum previously). This seems like a reasonable approach to this problem, though it doesn't mean that water won't migrate forward from the cockpit/companionway area and collect behind the bilge. Also bear in mind that when you heel that yucky water will migrate around the bilge, either from the bilge into the vermiculite or vice versa.

If you don't want to get radical with this repair, I would consider putting in an inspection port on this wet spot, so that it can be kept dry. Finding the low spot is the trick - I would look at the hull from the outside and identify the low spot as measured back from the trailing edge of the keel. The center seam is a consistent thickness (until you get right up to the sump, where its reinforced), so the low spot outside is the low spot inside. I have decided to put the floor down in such a way that I can open it along the center seam for cleaning and sponging (if necessary). I might also see if I can add laminate to this seam to give it a pitch that will allow it to drain. The way it was originally designed, this area simply can't be dried, short of standing the boat on its nose for a while. Later J's corrected this issue by ensuring that the bilge could drain continuously from both ends.

As an aside:

All early J's are very susceptible to wet core issues. If you do have substantial moisture, it will collect adjacent to the center seam since the water migrates downward. Plus, the core goes right up to the keel sump, so your weakest wettest core is right over the most stressed region of your hull. On my boat, the core around the sump was similar to the nasty sponge sitting on the edge of your kitchen sink (not kidding). That having been said, these boats are VERY heavily built with at least 1/2 inch of roving around the keel sump over the core. I suspect that there are many wet boats out there that have not had issues because this inner laminate is so strong and the keel sump is very rigidly built. My boat had no deformation or sign of stress related failure, but as a bit of a perfectionist (and former glass and rigging man at a shipyard), I figured I'd make this boat right while I was 'pimping' it out. If you do decide to do a recoring, considering doing parts of it from the inside. Doing it from the outside is much harder because you have to completely re-fair and unless you've got the boat upside-down, gravity is working against you. I am only recoring from the outside in places that can't be accessed from the inside. Bear in mind, these are structural repairs, so make sure you have a broad bonding margin between old and new. Also use epoxy and not poly or vinylester resin since non-epoxy resins do not bond well to cured or dissimilar materials.

Finally, if you don't have barrier coat on your boat, you're crazy. My boat got soaked from simple blisters. The outer laminate on these hulls is unbelievably thin (less than 1/8), so if you have a blister, its very unlikely that its just 'in the glass'. The previous owner had shoddy repair work done with generous use of inferior filler material that ensured that the problem just got worse and worse each year. If you do have some moisture, at a minimum repair the blisters with epoxy and colloidal silica (not polyester filler or marinetex!) and apply a barrier coat like Interprotect 2000 (goes on better than anything else I've used). If you can risk the sleepless nights, get one of these:
http://www.gesensing.com/products/aquant.htm?bc=bc_ge_protimeter

I'm looking forward to racing and cruising my J/30. A few people have asked me why I bought an old J/30 - I ask them to show me any ~30ft boat with superior speed and cruising amenities. You can name lots of boats with one or the other, but none with both.

Rich Miller
Burlington, VT
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 04/07/06 03:34 PM

Rich - Great description of the work you've done. I'm sure this will help lots of us with similar issues. When you get a chance, send me an email so I can contact you. My email is listed in my profile. I live in RI.

Regards,
Bill
Rhapsody - J/30 #348
Posted By: Phil

Re: Dewatering Aft Bilge - Need Advice - 04/07/06 05:41 PM

I have an older J-30 with the same moisture issue you describe on the starboard side of the hull.

Postings other places on this site indicate that the primary source of this moisture is from the engine exhaust.

I have had the area around the exhaust tube rebuilt and also have had the worst area of my hull where delaimation had begun (starboard stern quarter) re-cored.

Two questions:

1) What areas of mosture intrusion into the core did you identify, if any, other than the vermiculite/bilge line ?

2) Since I am not re-coring the entire starboard side of the hull would barrier coating be of any value? Since there is moisture in the core, isn't it almost certain to get into the laminate even if I barrier coat?
Posted By: D. Bartley

Re: Dewatering Aft Bilge - Need Advice - 04/07/06 10:27 PM

Great work Rich. Hope you're taking pictures as you go along.

Are you removing interior furniture, or simply (nothing simple about it I'm sure) the floor?
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/09/06 03:14 PM

Quote
Originally posted by D. Bartley:
Great work Rich. Hope you're taking pictures as you go along.

Are you removing interior furniture, or simply (nothing simple about it I'm sure) the floor?



I have only removed the floor and tanks, I plan on leaving the molded interior in place for the most part. In places where the core is wet and under an immoveable component, I will recore from the outside - for instance under the bulkhead and floor in the head/closet area. I've cut away some tabbing to allow for parts of the repair, but again, I'm leaving plenty of margin to scarf together old and new laminates. My tools of choice are a circular saw for cutting laminate and a sawsall for cutting tabbing and details. I also use a rotary trimmer for tight spots. A pneumatic chisel is key for attacking vermiculite and stripping away layers of laminate.

I had a bit of an ugly discovery yesterday (tearing things down really undermines one's ability to engage in selective denial). The aft-most keel bolt (aft of the last stringer) is badly rotten (1/2 of diameter is gone). On my boat, this bolt was tucked into a combination of resin and polyester fillter, which let the bilge water stagnate around and down into this bolt. Stainless is only rust resistant in the presence of oxygen (either air or moving water), since it relies on a coating of nickel oxide to remain 'stainless'. In stagnant water, stainless is very prone to corrosion and in my boat this has led to a badly deteriorated bolt. There is also evidence of spider cracking with rusty oxidation on the keel where this bolt is placed. If you see rust here, you've got at least some corrosion.

In general, it is best to keep your keel bolts bone dry. This means no cracks on the keel joint and no water penetration from the bilge. Generally speaking, the best approach to sealing the keel bolts is to 'cap' the bolt with a blob of thickened epoxy (thickened with lightweight and brittle agent like microballons). This cap keeps the bolts dry, yet can be chipped away for inspection. Don't encapsulate the bolt unless its completely dry.

I'm going to sister this bolt using a method similar to this one:
http://www.sailnet.com/collections/articles/index.cfm?articleid=caseyd0040

Using Aquamet 22 (which is more corrosion resistant - though not absolutely): http://www.machinist-materials.com/stainless_table.htm

This bolt was largely, but not completely covered by resin, which I strongly suspect is the reason it failed. On other J/30s, if this bolt is encapsulated, you may be fine. I'm not sure if this was a manufacturing defect or design defect. Also, I have yet to inspect the other bolts - I'm hopeful that their exposure to air kept them more intact. If they are shot, I may opt to drop the keel, or add a couple of extra sister bolts. Ugh.

This bilge area seems to be a major Achilles heel on this boat...
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/09/06 03:39 PM

Quote
Originally posted by Phil:
I have an older J-30 with the same moisture issue you describe on the starboard side of the hull.

Postings other places on this site indicate that the primary source of this moisture is from the engine exhaust.

I have had the area around the exhaust tube rebuilt and also have had the worst area of my hull where delaimation had begun (starboard stern quarter) re-cored.

Two questions:

1) What areas of mosture intrusion into the core did you identify, if any, other than the vermiculite/bilge line ?

2) Since I am not re-coring the entire starboard side of the hull would barrier coating be of any value? Since there is moisture in the core, isn't it almost certain to get into the laminate even if I barrier coat?




Unless your bilge is full of standing water, I'd say the overwhelming likelihood is that your core is wet from the outsite. This can be from blisters, damage to the outer laminate or a crappy thru-hull fitting. My engine's water intake (starboard) is bad and wet in the immediate vicinity. The rest of the core in that area is OK since there's no blistering.

The vermiculite is a great destination for water, but doesn't seem to impact the core it is next to. The inner laminate is several times thicker than the outer laminate, so its less susceptible to osmosis that penetrates the core. Not impossible that your water is coming from the inside, but it seems to me less likely.

The standing water aft of the bilge seems to collect on the center seam, which is solid glass, so, again I think the core is less likely to be impacted from the inside than the outside.

Finally, to reiterate: if you don't have a nice thick barrier coat, you're taking an unreasonable risk in *all circumstances*. A barrier coat slows or halts existing problems from worsening and keeps new problems from cropping up. Blistering gets more likely under three conditions:
- Warmer water
- Lower salinity
- Freezing weather in winter

So if you've got a boat up in Maine, you're likelyhood of blistering is mitigated (but still a substantial risk) since the penetration is slower. If you've got it in a freshwater lake in Texas, you're in prime osmosis territory. The other factors is the presence of freezing air while the boat is being stored. If you've got osmosis in your hull, but it never freezes when you're boat is on jack stands, your water may evaporate out without actually busting the surface (though it will still weaken the gel and laminate). If your soggy hull goes through a series of freezes in the winter, you've got a perfect set of conditions for expanding water to crack your gelcoat and develop classic blisters. Over time blisters always get worse if they are not fixed. If you have a substantially wet core, a barrier coat will slow the problem, but its not a fix by any stretch of the imagination.

Finally, one interesting thing to note. Since fresh water makes blisters *more* likely, special attention should be paid to 'Fresh water boats' on the market. This is great for some corrosion issues, but can actually be a check in the negative column as far as wet core issues go.
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/09/06 04:27 PM

Brief qualification (after several long rants in this thread - I type very quickly):

I tend to write with an 'authoritative' tone about all this (bad habit). Don't be fooled into trusting my judgement, or anyone else's for that matter, over your own investigation and experience.

Check with the class measurer before doing anything. I'm less concerned about one design considerations since my boat really is in rough shape and I don't have reasonable alternatives to my approach that will result in a safe vessel. I'm going to build this repair right - I'll document and share it with a measurer if we decide to race one design, but I'm not going to rebuild it with the same design weaknesses that it came from the factory with. The boat won't be lighter (If anything heavier) or manifest any changes to hull shape or handling, so I'll take my chances after the fact.

If you're a serious class racer, you should tread carefully and get class measurer approval prior to any modifications - especially that 12ft carbon bowsprit and bulb keel any of you might be planning on tacking on!

[Linked Image]
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/10/06 04:54 PM

I took some pictures this weekend that should answer a few questions for the curious.

Enjoy!
http://www.6degrees.com/j30/underthefloor

Rich
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 04/10/06 05:23 PM

Quote
Originally posted by 6degrees:
I took some pictures this weekend that should answer a few questions for the curious.

Enjoy!
http://www.6degrees.com/j30/underthefloor

Rich



Rich,

What you have shared is very valuable for many of us. I'm within 1 week of having Rhapsody in the water, and to quote one of the comments you have with the pictures "... it's not wise to go looking for trouble". I will stick my head in the sand until the end of this season, then do some more investigating. I don't have the skills to do a major repair like this without professional help (that may mean the shrink too!).

Good luck on the balance of your repairs. I'd love to see your finished work.

Bill
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/10/06 07:49 PM

Quote
Originally posted by whk:

Rich,

What you have shared is very valuable for many of us. I'm within 1 week of having Rhapsody in the water, and to quote one of the comments you have with the pictures "... it's not wise to go looking for trouble". I will stick my head in the sand until the end of this season, then do some more investigating. I don't have the skills to do a major repair like this without professional help (that may mean the shrink too!).

Good luck on the balance of your repairs. I'd love to see your finished work.

Bill


Thanks!

I'm sure I'll document and post info as I go along. Until then, its going to be an epic task to get done.
Posted By: mjr

Re: Dewatering Aft Bilge - Need Advice - 04/12/06 02:30 PM

Rich,
Bill just turned me on to this discussion. I'm in the middle of epoxy sealing my entire bilge on Nemesis (#435), and adding an electric bilge pump system. I started by taking a large diameter drill bit and rattled around the bilge knocking off anything that even thought about being loose before any epoxy hit it. I must also say that the bilge was totally dry for the whole winter, and only saw water when I washed it down a few days before the drill hit it. I've brushed the straight West System epoxy resin onto all verticle areas of the bilge, and pourd it in to the bottom. However, it is not so thick as to cover the keel bolts. All are bolts and washers are exposed on top. My concern is the drain from the "Other Bilge". I have no opening for it. Where should we expect to see that? Between the bilge pump and cooler drain hoses? To the side of one? Should I drill a new one back from next to either hose? I need a clue as I'm ready to paint and now's my last best chance to have a nice job done.

Thanks for all your time and effort in sharing this with us.
Mark R.
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/13/06 03:47 PM

Quote
Originally posted by Mark Rotsky:
Rich,
Bill just turned me on to this discussion. I'm in the middle of epoxy sealing my entire bilge on Nemesis (#435), and adding an electric bilge pump system. I started by taking a large diameter drill bit and rattled around the bilge knocking off anything that even thought about being loose before any epoxy hit it. I must also say that the bilge was totally dry for the whole winter, and only saw water when I washed it down a few days before the drill hit it. I've brushed the straight West System epoxy resin onto all verticle areas of the bilge, and pourd it in to the bottom. However, it is not so thick as to cover the keel bolts. All are bolts and washers are exposed on top. My concern is the drain from the "Other Bilge". I have no opening for it. Where should we expect to see that? Between the bilge pump and cooler drain hoses? To the side of one? Should I drill a new one back from next to either hose? I need a clue as I'm ready to paint and now's my last best chance to have a nice job done.

Thanks for all your time and effort in sharing this with us.
Mark R.


Sealing the bilge is a good idea. Sealing the keelbolts is also a good idea, if they are completely dry. I'll be inspecting all of my bolts before I seal them to be sure I don't trap moisture in there, which is would be worse than having them alternating between wet and dry. You'll also want to be sure your keel joint is completely dry before you seal anything. Its an all or nothing proposition - totally dry and sealed, or unsealed and as ventilated as possible.

As far as sealing them with solid resin, this doesn't seem like a good idea to me. Resin is super hard stuff and removing it will be nightmare when you want to inspect you bolts. If you use a lightweight filler like microballoons, it will be relatively brittle (still extremely tough), so you can chisel it off without too much pain and suffering. I also wouldn't bury the entire bolt in resin, just cover it with a blob. I'm pretty heavily referencing this article:
http://www.sailnet.com/collections/articles/index.cfm?articleid=caseyd0040

As for the 'Other Bilge', there is no drain other than whatever water can weep around the drain hose that is buried in the vermiculite under the floor. Because of its position, it doesn't drain and is therefore a prime spot for nasty moisture to accumulate, especially if your 20+ year old bilge hose leaks. So I don't have an easy answer to your question - its lower than the lip of the bilge, so it can't drain. I've floated the idea in a previous post in this thread of adding an additional hatch in the floor over this spot so it can be sponged out periodically. This would entail cutting out the hatch, digging out the vermiculite and old cruddy hose and fabricating some sort of latch to keep this new part of the floor from falling out every time it gets stepped on. Here's a rough image of what I'm thinking of:
http://www.6degrees.com/j30/underthefloor/bilge.jpg
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 04/13/06 05:52 PM

Quote
Originally posted by 6degrees:
....
As for the 'Other Bilge', there is no drain other than whatever water can weep around the drain hose that is buried in the vermiculite under the floor. Because of its position, it doesn't drain and is therefore a prime spot for nasty moisture to accumulate, especially if your 20+ year old bilge hose leaks. ...



Rich,

Mark & I talked about taking a long drill bit (maybe ~ 3/8" diameter) and drilling a hole from the lower edge of forward bilge next to the drain hose, aft into the vermiculite. Both Mark & I have experienced water "magically" appearing in that little flat section of the forward bilge. Sponge it up, and it returns in about 10 minutes. If the water is trying to weep past the bilge hose, couldn't we just give it an easier path to flow forward? I realize this would be a temporary fix until the real problem of drainage in that area gets solved. Any opinions on this?

Tnx,
Bill
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/13/06 06:27 PM

Quote
Originally posted by whk:
Rich,

Mark & I talked about taking a long drill bit (maybe ~ 3/8" diameter) and drilling a hole from the lower edge of forward bilge next to the drain hose, aft into the vermiculite. Both Mark & I have experienced water "magically" appearing in that little flat section of the forward bilge. Sponge it up, and it returns in about 10 minutes. If the water is trying to weep past the bilge hose, couldn't we just give it an easier path to flow forward? I realize this would be a temporary fix until the real problem of drainage in that area gets solved. Any opinions on this?

Tnx,
Bill


Seems like it could help move this water forward as it sloshes around. If your boats are built like my boat, it still won't be able to drain uphill. I'd also be cautious about damaging the hull laminate or the pump and ice box hoses.

It is possible that if you kept your main bilge dry and installed a new bilge hose (so pumping out wouldn't leak water into the Other Bilge, this area might stay pretty darn dry. I don't know how much water is entering from the aft half of the deck, so this may or may not be helpful.

Rich
Posted By: mjr

Re: Dewatering Aft Bilge - Need Advice - 04/13/06 06:46 PM

To further Bills comments, I came up with a possible plan to allow for better drainage/pumpout of the second bilge. Let me know what you think as it came to me at 2:00 am this morning. Drill the hole Bill suggested far enough to reach the area that should be the low point in the second bilge. Obvious risk in drilling through one of the existing hoses, or worse. The hole diameter should be big enough to accept a fuel hose for a typical dingy outboard motor. By using the bulb pump that is on almost every dingy fuel line, the second bilge can be pumped as dry as the hose position allows. If you seal the area with silicone where the hose penetrates the vermiculite, you don't refill the second bilge from the first. You could even pull the bulb off the hose, but leave the bulb's first check valve with the hose, then attach another hose to it that ends in the bottom of the first bilge. This way if there is a large quantity of water, or whatever, that gets into the second bilge, it may reach far enough into the hose to empty into the first bilge, and even start a siphon that sucks the second bilge dry(er). The retained check valve eliminates the risk of, again, backfilling the second bilge through the hose.

OK, does this sound like a 2:00 am save the world scenario, or what?

Any thoughts? (Or was this too painful?)
Mark R.
Posted By: dbows

Re: Dewatering Aft Bilge - Need Advice - 04/14/06 02:06 PM

I have the same scenerio with the rear flat part of the bilge filling with a bit of water. Mine is/was coming from a crack in the large bilge hose right at where it goes under the floor. I am having to do the famed project of running a smaller hose through this larger one. I suspect this will fix my leak.

Also I have a smaller diameter hose that runs out of back of the bilge right on the centerline. Does this drain the "second bilge" or is it the icebox drain?


David
#397
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/14/06 04:27 PM

Quote
Originally posted by dbows:
I have the same scenerio with the rear flat part of the bilge filling with a bit of water. Mine is/was coming from a crack in the large bilge hose right at where it goes under the floor. I am having to do the famed project of running a smaller hose through this larger one. I suspect this will fix my leak.

Also I have a smaller diameter hose that runs out of back of the bilge right on the centerline. Does this drain the "second bilge" or is it the icebox drain?


David
#397


Consider running a full sized bilge hose under the settee and into the bilge. This leaking pump hose seems like it could be the primary source of water back there, though on my boat, it had a new smaller hose installed, so the water that was stuck in there was coming from elsewhere.

As for the other hose, its the icebox drain. You could check this by pouring a little water into the icebox and seeing where it comes out.
Posted By: dbows

Re: Dewatering Aft Bilge - Need Advice - 04/14/06 05:02 PM

Quote
Originally posted by 6degrees:
Consider running a full sized bilge hose under the settee and into the bilge. This leaking pump hose seems like it could be the primary source of water back there, though on my boat, it had a new smaller hose installed, so the water that was stuck in there was coming from elsewhere.

As for the other hose, its the icebox drain. You could check this by pouring a little water into the icebox and seeing where it comes out.



I looked into doing this but there is no way to get a hose into the settee. There is a small passage but is max 1/2 inch high and it aligns directly into the water tank. How have others done this?

David
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 04/15/06 12:20 AM

Quote
Originally posted by dbows:
I have the same scenerio with the rear flat part of the bilge filling with a bit of water. Mine is/was coming from a crack in the large bilge hose right at where it goes under the floor. I am having to do the famed project of running a smaller hose through this larger one. I suspect this will fix my leak. ...


David
#397


David (or others who've done the smaller hose trick),

What diameter hose are you using, and does this go all the way aft to the Whale Gusher? Not sure if it is better to pull the smaller diameter hose through then entire length, or just splice a section with adapters through the "hidden bilge" area.

Bill
#348
Posted By: dbows

Re: Dewatering Aft Bilge - Need Advice - 04/15/06 02:21 PM

Quote
Originally posted by whk:
David (or others who've done the smaller hose trick),

What diameter hose are you using, and does this go all the way aft to the Whale Gusher? Not sure if it is better to pull the smaller diameter hose through then entire length, or just splice a section with adapters through the "hidden bilge" area.

Bill
#348


Bill,

I have been thinking about this and I am not sure which is best. I am of the mindset that I want a single hose to reduce points of failure however my Gusher pump will not handle the smaller hose so I will have a "step-up" anyway. I am not sure what the difference would be to that vs. grafting in a smaller run just through the old hose except the failure point would be more accessible if it was next the pump rather than down in the cabin.

I think the new hose is 1 1/8th. I will measure it while I am on the boat today since this is on my to-do list for the weekend.

David
#397
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/16/06 12:42 PM

Quote
Originally posted by dbows:

I looked into doing this but there is no way to get a hose into the settee. There is a small passage but is max 1/2 inch high and it aligns directly into the water tank. How have others done this?

David


Under the settee, there are two cutouts toward the bilge, with gaps under the floor to allow drainage. These channels are formed by blobs of vermiculite between the floor and the hull, so we're not talking about a consistent size passage here. It sounds like there just isn't enough room to jam a hose in. On my boat, it looked like with a little chipping, I would have been able to squeeze a hose through on the port side. That said, having never bothered to try it (and subsequently opting to rip out the floor), I can't say if it ever would have worked. Sounds like the classic 'small hose through the old hose' trick is your best option.

Rich
Posted By: mjr

Re: Dewatering Aft Bilge - Need Advice - 04/17/06 07:03 PM

Well, I went drilling for gold this weekend. Got a extra long 1/2" drilll bit and went at it just starboard and below the ice box drain hose. Went in about 5 or 6 inches aiming for the centerline and got 95% dry sawdust. The other 5% was just moist enough to pack into one sipe of the bit, but fell out easilly when touched. That's about as far as I dare go. Plugged the hole with a rubber cork so as not to start a problem that didn't exist. I may try to drill one more much smaller hole below the pump hose just to see if anything comes out there. If dry, I'll seal it up and focus my attention elsewhere.
Mark R.
Posted By: Rhapsody #348

Re: Dewatering Aft Bilge - Need Advice - 04/17/06 07:22 PM

Quote
Originally posted by Mark Rotsky:
Well, I went drilling for gold this weekend. Got a extra long 1/2" drill bit and went at it just starboard and below the ice box drain hose. ......
Mark R.


Further to Mark's exploratory drilling, I found standing water underneath the main sink. I sponged it up and water was back the next day. The source appears to be from the "hidden bilge", as I had similar puddles appear in the center bilge by the bilge hose joint. The water is definitely not from the sink drain or the fresh water foot pump. I spoke to Mark and am going to borrow his outboard siphon bulb pump. Plan is to drill a hole in the plywood base that holds the foot pump large enough for the hose to fit through, and then see how far I can snake the hose. I may try and pull that entire base assembly just to see what the opening to the water source looks like.

Rich - have you got visibility under your sink to the "hidden bilge" since you've got your floor apart? Is there a path for water to get under the sink area from there?

Bill


[This message has been edited by whk (edited 04-17-2006).]
Posted By: 6degrees

Re: Dewatering Aft Bilge - Need Advice - 04/17/06 08:03 PM

Quote
Originally posted by whk:
Further to Mark's exploratory drilling, I found standing water underneath the main sink. I sponged it up and water was back the next day. The source appears to be from the "hidden bilge", as I had similar puddles appear in the center bilge by the bilge hose joint. The water is definitely not from the sink drain or the fresh water foot pump. I spoke to Mark and am going to borrow his outboard siphon bulb pump. Plan is to drill a hole in the plywood base that holds the foot pump large enough for the hose to fit through, and then see how far I can snake the hose. I may try and pull that entire base assembly just to see what the opening to the water source looks like.

Rich - have you got visibility under your sink to the "hidden bilge" since you've got your floor apart? Is there a path for water to get under the sink area from there?

Bill


[This message has been edited by whk (edited 04-17-2006).]


I've got that area opened up. Once you unscrew and pull the plywood floor under the sink, you should see the edge of the molded interior and a few inches beyond it the vermiculite the floor is sitting on. If you have standing water under the sink and you think it might be continuous with the water in the 'other bilge', I'd think it would be leaking forward into the main bilge by then - not up to the sink. I guess I'm not sure how water under the floor, which is presumably lower would, would rise up to under the sink, unless your boat was really swamped.

If you look at the shots on my website, you can see that the vermiculite stops forward of the sink. I could see how water might enter from aft of the sink and collect up against the vermiculite. I'm guessing this water might contribute to keeping the 'other bilge' wet, but I don't think its source could be lower than the area you are describing. I'd see if you could spot where water might be flowing in from the deck, deck hull joint or companionway and collecting here. Maybe if you stop this leak, you can do a better job of keeping the other bilge dry.

On my boat, there were multiple places in the cockpit that had leaks around hardware, which I'm sure put water into the bilge. I just finished recoring these things, so I'm feeling like it should be pretty dry. I'm actually planning on glassing in all of the wood features on the deck for 'all glass' look and to prevent leaks around teak. I hate varnishing.

Rich
Tres Cosas
#294
Posted By: j30521

Re: Dewatering Aft Bilge - Need Advice - 05/17/06 05:20 PM

Thanks to all who have contributed to this thread which should be most valuable to anyone willing to "hang in there" with the boat and facing significant refurbishment issues below the cabin sole.

My remarks concern Hull 521 which has a "half-length" engine cover) but they should be germaine to the issue of keeping the "hidden bilge" below the engine dry on many if not all of our boats.

On my boat the "hidden bilge" under the engine is kept dry with frequent inspections and "sponging" or "paper-towelling" through a 3" inspection hole cut into engine bed liner forward of the engine and slightly to port - previously described by other members. More importantly, significant water ingress to that "hidden bilge" drains into the main bilge through the passage which originally accomodated the manual bilge pump hose when the boat came from the factory. The original hose was removed and one of a slightly smaller diameter was passed from the main bilge to port under the settee then aft through the sink / battery compartment and through a hole in lazarette bulkhead to the manual pump. Admittedly, the reduced diameter of the non-OEM hose along with two necessary 90-degree elbows compromise the capacity of the manual pump somewhat and if I felt that it was an issue I needed to address I would have to grind/file/saw/curse larger passages to accommodate the larger (OEM diameter) intake hose from the bilge to the pump. But it is now the work of 15 seconds to remove the engine cover and dry out the "hidden bilge" which I accomplish every time I check the engine oil prior to getting underway or any time that I suspect that water may have entered the area.

There are several sources of water into the "hidden bilge", chief among them being any water from the companionway area which runs down the side of the engine cover into the molded retaining groove and its drain holes on either side and water from the stuffing box (resulting from my chronically delinquent maintenance / replacement) which sloshes into the cutouts in the liner under the engine mounts when the boat heels at all.

I hope that this helps all those willing to lose a little manual bilge pump efficacy in exchange for an enhanced ability to keep that "hidden bilge" area as possible.
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