Author Topic: Bilge Modification (Proposed) (Read 9375 times)

dawntreader · « **on:** March 10 2018, 07:57 »

I had a leak from my new thru-hull fittings which was found (and sealed) after a small amount of clean seawater was found in one of the bilge compartments. Weeks later more water appeared but no leak was evident. What had happened is the water had gone into the drain holes (which bring the water to the bilge pump) of the cross-members. These cross-members are hollow and there is a 'lip' which retains the water inside them but out of sight. It was difficult to remove the residual water but this has now been done. I am considering pushing a tight-fitting plastic tube through the holes to maintain water flow to the bilge pump but seal the outer edges where it enters the holes with mastic to waterproof the internal part of the cross-members.

Any considerations or comments on this proposal?

Odysseus · « **Reply #1 on:** March 10 2018, 13:19 »

My fix to get the liquid out of the ribs was to use my 12v oil change pump, 15 min job .

Put "motorbike oil change pump in EBay" and they are about £10. Work well however if water is pumped put some wd40 through afterwards keep the vanes inside working.

HOPE THIS HELPS

Odysseus
Bad 38

Craig · « **Reply #2 on:** March 10 2018, 23:09 »

I would be reluctant to put plastic tubes in the limber holes.

After having an exploding heads tank where the waste flowed under the heads moulding and into the floor frame, I found it difficult to remove the waste from inside the floor frame. This would have been impossible if I had plastic tubes through the limber holes. I have no idea how much waste got into the grid, or exactly where it got in. It appears there may have been an unsealed pathway somewhere under the holding tank or under the heads moulding.

Unfortunately the solution proposed by Odysseus is probably the best.

I used this method to remove the waste. I did find that I needed to reduce the size of the standard pick-up tube. The smaller the pick up tube the easier it is to get the last bits of waste or water. I still needed to roll some paper towel into a cigar shape and poke into the limber holes to get out the last couple of drops.

Craig
"Shirley Valentine"
Gold Coast
Australia

dawntreader · « **Reply #3 on:** March 11 2018, 07:45 »

Thanks to Craig and 'Odysseus' for comments made. I have a version of the 12v oil sump pump so could have used that. However, I used the 'cigar' solution mentioned but with a rolled-up micro-fibre cloth - very effective but tedious. Referring to the comment on the toilet waste: if the plastic pipe was of a thin-walled construction it should not reduce the size of the holes significantly. It would also prevent any waste moving 'sideways' into the grid which, I assume, would be difficult to remove. That event has made me think I will do a trial on one of the sections to test the proposal

Thanks again

tiger79 · « **Reply #4 on:** March 11 2018, 15:44 »

Quote from: dawntreader on March 10 2018, 07:57

I am considering pushing a tight-fitting plastic tube through the holes to maintain water flow to the bilge pump but seal the outer edges where it enters the holes with mastic to waterproof the internal part of the cross-members.

I think this is now done by Bavaria in production.

Ricd · « **Reply #5 on:** March 12 2018, 12:09 »

If you have ever had a a leak on say a stanchion or toe rail on the deck, the water always ends up in the bilge. Its route is via the holes on the hollow cross sections/stringers/rib section you are considering effectively sealing from the bilge. If these are isolated from the bilge where will that water go? I would think again.

cheeers
Richard

dawntreader · « **Reply #6 on:** March 13 2018, 07:40 »

Quote from: Ricd on March 12 2018, 12:09

If you have ever had a a leak on say a stanchion or toe rail on the deck, the water always ends up in the bilge. Its route is via the holes on the hollow cross sections/stringers/rib section you are considering effectively sealing from the bilge. If these are isolated from the bilge where will that water go? I would think again.

cheeers
Richard

As I cannot find the 'ends' of the cross ribs does anyone know if this statement is true - that is, are the ends of the cross-members open so that water flows into the cross-member and out of the holes? Sorry, but seems unlikely to me

Yngmar · « **Reply #7 on:** March 13 2018, 09:11 »

The ends aren't open, but there are large holes where hoses are routed through.

Ricd · « **Reply #8 on:** March 13 2018, 10:39 »

I can only say that when I had a persistent leak of fresh water (for many weeks whenever it rained) into the bilge in saloon, we traced it to the forward port toe rail. After fully drying the bilge and ribe/stringer water was visible flowing into the bilge under the saloon table from the hole in the rib/stringer with me on deck with a hose flooding each part of toe rail in turn and wife below monitoring when water flowed from the hole. This allowed us to identify problem area. I withdrew toe rail screws and siliconed threads and re-screwed them back solved problem - 8 years ago.
QED - water from deck leak (toe rail or stanchion) can get to bilge via the rib/stringer. So if you bock the exit hole where will that water then go?

Salty · « **Reply #9 on:** March 13 2018, 23:19 »

I'm with Richard on this, the most important thing is that any water leaking into the bilge area, no matter where it comes from, can get back to bilge pump suction as quickly as possible. Anything that hinders that flow is a disaster waiting to happen.

dawntreader · « **Reply #10 on:** March 14 2018, 07:47 »

OK, I'm convinced - no hose

Salty · « **Reply #11 on:** March 14 2018, 20:21 »

Ref Dawntreaders question at reply #6 and also Yngmar's photo in reply #7
"As I cannot find the 'ends' of the cross ribs does anyone know if this statement is true - that is, are the ends of the cross-members open so that water flows into the cross-member and out of the holes? Sorry, but seems unlikely to me."

I can say that on my B36(2002), that the two longitudinal ribs or floors running one each side of the engine bay are open at the after ends, and that these feed through the intervening ribs/floors to the bilge suction area located between the second and third transverse rib/floor forward of the engine bearers. Whether the same applies to all Bavarias I think may be unlikely, but on my boat it means that a significant oil leak in the engine bay could result in oil contamination of those ribs/floors and the main bilge suction area.
However, following Dawntreaders comment I'm curious, so this year I'm going to try to answer that question in regard to my B36, maybe others might like to investigate their own boats and reply so that we can all learn from it.

dawntreader · « **Reply #12 on:** March 15 2018, 07:33 »

Good point 'Salty'. My boat is a B37 2006 and I will do the same.
Jim

dawntreader · « **Reply #13 on:** March 16 2018, 07:44 »

OK, now had a good look. The area under the engine is a 'sealed' compartment (as in photo earlier this thread) so any spillage will be contained. However, the forward bilge compartments have more openings than I first thought. There are larger holes to the top of the ribs that, if the spillage was sufficient, would allow ingress. I cannot see how any water could enter the rib grid other than through these holes as the ends are sealed [B37, 2006]. As there are too many larger holes (some difficult to access) I do not intend to pursue the modification I proposed

Ricd · « **Reply #14 on:** March 16 2018, 08:54 »

Just to comment on Salty’s observation. Two years ago we ad a poorly fitter course fuel filter that dripped diesel. Apart from the smell, I discovered the problem when I saw diesel in the main saloon bilge compartment. As with the deck water leak, the diesel arrived in the bilge via the hole on the rib/stretcher. Please note, I keep a perfectly dry boat. One of my routine checks is to look in the saloon bilge for sighs of leaks...if found then work out the source. Another source detected in this way was a leaking domestic water pump located under aft port cabin. Again this only became obvious due to water collecting in saloon bilge.

Moodymike · « **Reply #15 on:** April 02 2018, 15:53 »

I have just found fresh water in the central bilge pump area. Can see it flow from the first stringer when I move to s/b side. I suspect from the deck area either from snow or a pressure wash. I cannot see how it can enter the stringers from the hull sides.

just found this quote from a 2008 B37 review "The bilge compartments are connected by drilled limber holes so water can collect at the deepest point. A nice detail is the installation of glued-in tubes that keep water from seeping into the timbers and stringers. "

dawntreader · « **Reply #16 on:** April 02 2018, 20:02 »

I wish they had done that with the 2006 model

$:-\$

artemis · « **Reply #17 on:** April 03 2018, 18:12 »

I've a Bavaria 34 CR I bought back in 2007, I had fresh water turning up in the bilge every now and then. I was stumped where this water was coming from eventually I removed all the toe rail's and stanchion's rails, Low and behold behind the toe rails there was hardly any sealant and in some places i was looking right into the boat lol...

Ended up re-sealing the hole yacht inc cleats etc etc. Since then I would be lucky if I've had a half cup of water in the bilge

Mike
Artemis

Moodymike · « **Reply #18 on:** April 04 2018, 10:55 »

Can you describe how you tackled “removed the toe rail”. Did you remove the whole thing or just prize up? Are the holding screws self Tapping?

artemis · « **Reply #19 on:** April 04 2018, 21:31 »

Hi There

I removed the whole toe rail's Its in 2 sections port & stbd plus the cleats etc. removed all the screws when I removed the front post section the front 3 mtr's had no sealant what so ever behind it. I wandered why the fwd cabin was always getting damp and the cushions wet. It was not that big a job a couple of days max its better if there is 2 of you for taking nuts off in the inside though was well worth the trouble thats for sure. Yes the screws was self tapping but when I put back some would not hold so ended up using tapered bolts. Same on the cleats I used tapered bolts with locking nylon stainless nuts.

Mike

Moodymike · « **Reply #20 on:** April 04 2018, 22:52 »

Thanks for the info, not heard of the term tapered bolts before? Mike

artemis · « **Reply #21 on:** April 05 2018, 21:28 »

Ok a machined screw lol Philips head and nut on bottom.

Mike

Ricd · « **Reply #22 on:** April 17 2018, 13:04 »

Just returned to boat after lay up to find Diesel in saloon bilge "again" exiting from the hole in the stretcher. Traced source to a pool of diesel below the floor of aft stb locker, next to fuel tank. It resulted from over zealous brimming of tank/filler pipe over winter to avoid condensation. Cleaned up pool beside tank and in saloon bilge. Then poured a couple of litres of Bilgex solution into the locker beside the tank, where the diesel pool had been,....it all came out in the saloon bilge via said hole in stretcher over next 3 hours. QED