Venting/Drying a dry bilge

[dianamay]

With work by ourselves due to start on our sailaway in the new year we have been browsing the forums for

good ideas on fitting out including the thread specific to this topic and have a thought. Whilst we

realise that the "dry bilge" should be just that it is apparent that by its very nature water seem to find its way everywhere. So to that end what would members think of the idea of under floor venting which could

periodically be "turned on" to assist a drying process of for example condensation. Would this be an

unnecessary addition and actually not practical. I have no method in mind purely the nucleus of an idea

the reaction to which would be appreciated. Stupid?? Please comment.

[Southern Star]

It would certainly be a good idea to assume that water will find its way into the bilge and have some way of removing it. My boat doesn't have any bilge ventilation and installing some is very high on my "to do" list, although when I first cut an access into the cabin floor I imagine it will need several bucketfulls of water pumping out before I even consider ventilation....

[bottle]

Leave gaps between the floor and the walls behind your galley cupboards, an inch will be plenty and it will also help the fridge if you have one.

 

That is all I have and some gaps where the radiator pipes come through the floor, standby for the big intakes of breath as many say pipes should not be under the floor, well mine are all of them.

 

Try to insert an inspection hatch as far towards the back of the boat, in front of the plate that separates your engine bilge from the boat bilge.

 

My boat six years old, CCing live aboard, bilges are dry and always have been.

[Guest]

Leave gaps between the floor and the walls behind your galley cupboards, an inch will be plenty and it will also help the fridge if you have one.

 

That is all I have and some gaps where the radiator pipes come through the floor, standby for the big intakes of breath as many say pipes should not be under the floor, well mine are all of them.

 

Try to insert an inspection hatch as far towards the back of the boat, in front of the plate that separates your engine bilge from the boat bilge.

 

My boat six years old, CCing live aboard, bilges are dry and always have been.

Good idea leaving gap under galley, wish I had thought of that.

[blackrose]

If I was starting from scratch all I would do is lay the ballast on something like lengths of old cables or 5mm plastic spacers to allow the water to drain to the cabin stern. That and an inspection hatch in the floor at the stern should be all you need. A decent wet vac can be used to empty any water that does get under there through the inspection hatch.

 

I've been living on my boat for 10 years and had the occasional accident which caused water to get into the bilges, usually my own fault. However much you try to avoid it, one day it will happen.

Edited December 6, 2015 by blackrose

[Québec]

Post deleted on grounds of stupidity.

Edited December 7, 2015 by Québec

[Capt Ahab]

I dont think you need to introduce and forced ventilation to the bilge. I lifted the floorboards in our 12 years old boat today in the main cabin and the bitumen coated base plate beneath the slabs showed no evidence of any historic condensation. I would cut an access hatch as far back as possible to let you mop out any spilled water (we had a few problems with a holding tank but the less said about that the better!) but this all dried out within a few weeks of the spill.

[dmr]

Leave gaps between the floor and the walls behind your galley cupboards, an inch will be plenty and it will also help the fridge if you have one.

 

That is all I have and some gaps where the radiator pipes come through the floor, standby for the big intakes of breath as many say pipes should not be under the floor, well mine are all of them.

 

Try to insert an inspection hatch as far towards the back of the boat, in front of the plate that separates your engine bilge from the boat bilge.

 

My boat six years old, CCing live aboard, bilges are dry and always have been.

 

Its a nice idea but just think of all the stuff you could loose down there. Rice, broken biscuits and crisps, burst bags of bread flour etc etc. This could make a sort of sponge to retain any water that gets down there. A raised edge should help.

 

................Dave

[SUIGENERIS]

I have included 4 additional roof vents ( ecs type) set about 6 inches in from the sides of the roof, two at the bow and two at the stern, they are ducted with 9" x 1" plastic vent duct , via flat elbow adaptors ( all from toolstation ) running within the wall cavity down to the bilge area below the floor. this ensures a circulation of air. Seems to work well.

 

Mick

[blackrose]

 

Its a nice idea but just think of all the stuff you could loose down there. Rice, broken biscuits and crisps, burst bags of bread flour etc etc. This could make a sort of sponge to retain any water that gets down there. A raised edge should help.

 

................Dave

Sounds like a good rodent habitat...

[Jamm]

We keep a plastic bowl under the stern gland, and occasionally use this battery operated syphon pump to empty it if it doesn't evaporate naturally. The bilge itself stays dry....well, most of the time.

You're talking about the stern bilge. The topic is about the cabin bilges.

[Québec]

Oops...yep....apologies.

(Note to self: do not attempt to read/post anything on CWDF unless stone cold sober....liable to write a load of bilge)

[TheBiscuits]

Post deleted on grounds of stupidity.

I think that might be against forum rules.

 

Where would this site be if everyone did that!

[John V]

I have several access hatches through the boat (the one furthest aft doubles as a wine bottle store) plus a couple of ventilation grills aft near the stairs from the wheelhouse (well ventilated) and another pair near the woodburner (which is just fwd of midships) the biggest problem I have is spiders in the bilge

 

over the years have had a couple of floods (death of a waterpump) and overfilling a water tank before a necessary modification on an overflow pipe

 

 

must add that as a salty water boater I am paranoid as regards access to every part of the hull

Edited December 7, 2015 by John V

[blackrose]

must add that as a salty water boater I am paranoid as regards access to every part of the hull

I once met a bloke who'd fitted his boat out with a wooden floor which could be easily lifted in small sections to access any part of the bilges. No screws had been used, it was a fully floating floor. I think I'd probably do the same thing in future as I've cut several hatches but you can never get everywhere.

[koukouvagia]

My approach is to have removable, loose sections at the edge of the floor along the full length of the cabin. I like to keep an eye on the state of the bilge to make sure that it's bone dry.

If there is any plumbing leak water will always trickle to one side or the other but usually it finds its way to the back,

 

I'm fortunate in that there is no ballast to impede ventilation or the movement of water in the bilge.

 

[Bee]

There is probably something to be said for a piece of vacuum cleaner hose taken from the engine air filter and stuffed through a hole in the floor , get a lovely draught under the floorboards.

[trackman]

We've had 2 real leaks in almost 10 years, one a failed water pump under the front deck and the second a split in the calorifier under the bedroom wardrobe.

 

Both soaked the bilge area affected pretty thoroughly. Neither area stayed damp for long after basic mopping up with disposable nappies and/or cloths. We have good access points in the bedroom floor both sides at the rearmost end of the cabin adjacent to the bulkhead by the engine room.

 

After each flood the residual damp dried out naturally without forced ventilation. Our boat has nice clear spaces below the floors with no ballast so air can circulate freely.

 

The ballast is under the back cabin floor where the extra height for the prop shaft makes it very accessible, as is any water or condensation under there. We do get condensation there in winter if we leave the kettle boiling too long on the back cabin stove!

[DHutch]

One think I would certainly say its, make sure you paint the inside well, and endure their is a sound vapour barrier.

 

Our boat 25yo, and has as far as we know never had a major leak, although there is sometimes water in the rear of the main cabin bilge, normally its dry. The is basically no rust at all. In the engine room its always wet but very oily, which is also but we are just starting to go through the last of the paint into the primer from wiping it up (steam engine) the rear cabin bilge is often more damp as it includes the wheelhouse which sometimes is down when its raining for a whole, depending on the weather and canal, etc. There is rust here, but we are not worried yet.

 

Dont have lead ballast in contact with the hull, you get galvanic corrosion.

 

Daniel

[Tam & Di]

I have included 4 additional roof vents ( ecs type) set about 6 inches in from the sides of the roof, two at the bow and two at the stern, they are ducted with 9" x 1" plastic vent duct ......

 

 

I did that when I converted our ex-working barge in the early 90s - I foam-sprayed the plastic guttering that I used into position. I only have three vents, one of which had a solar powered fan to induce a gentle flow, but that failed after a while as they do. The boat is occasionally left for maybe 2 months at a time but always smells perfectly sweet and damp-free each time we return, even now after some 20+ years.

 

Tam

[NorthwichTrader]

We've got a 1" gap the entire length of the boat between the cabin sides and the floor (both sides). These are/will eventually be covered by a little box section with vents in.

Also, our new fire has got a 1" gap behind the fire board that will pull cold air directly from the bilge and hopefully blow it out the top, creating a flow through...our fridge should do the same.

We also waxoyled our bilge prior to putting in our ballast. 5ltrs of the 'spray-type' waxoyl can be bought in halfords for around £30. We warmed it up slightly, and splashed it on thickly with a brush. Really glad we did that.

Be careful warming it, it's flammable. Also it stinks to high heavens for a week (at least), so don't have any plans to sleep aboard at the time.

Best of luck with your project,

Stuart

[rustydiver]

Curiosity got the better off me.

I bought some soffit vents from toolstation to put under the bed to vent it it always smelt musty and the water heater is under there, I decided I would drill a hole into the floor to see if it's wet or dry it was in th middle off the boat about 3 ft away from the tear door and it was bone dry, there was sill sawdust down there when they fitted the boat out, I could feel a draft coming through. I was supprised how shallow it was under the floor.

When I go back next time I'm going to Hoover it out and stick the camera down there to ave a good look.

The hole was 70mm. I can recover the hole or fit a vent into it.

Going to do the same in the front off the boat.

[blackrose]

There is probably something to be said for a piece of vacuum cleaner hose taken from the engine air filter and stuffed through a hole in the floor , get a lovely draught under the floorboards.

But not so great if you happen to have some water in the bilges under the floorboards which then gets sucked into the engine.

 

There's a reason air filter intakes are on the top (or high up) on the engine.

Edited December 29, 2015 by blackrose

[bigcol]

The bow of our boat, houses a big stainless steel water tank, underneath this is the BT tube and bow thruster and battery's.

Due to finding out BT is not working, I took the bed and bulkhead dividing wall off between the bow of boat and the main bedroom.

 

Dark hole of Calcutta, it was sopping wet, the tank dripping Dow condensation onto the BT, which is now out and getting repaired due to the amount of moisture.

The tube also is sopping wet.

I had tried to seal cold bow area from, bedroom warm room, but this hasn't worked?

I've now got a small dehumidifier and small house fan in there trying to dry out.

 

By trying to seal the bow area of from main living, still getting massive condensation.

Do I no just put vents in the bulkhead, letting BT area cold air circulate freely with the main bedroom warm air or just leave a fan in their and running it in the winter.?

 

Any ideas or suggestions again, I had this problem last winter, with the BT having to be dried out, which is why I tried to seal the area, but this hasn't worked?

Our engine bilge and others are spotless, this is the one place I've obviously failed.

I've including some pics or this to be accepted. Before the BT tube was installed all the insulation foam on the walls of the space was intact, the bottom of the water tank is dripping fondest ion helped by the tube. Any sugestions re how to ventilate this area will be gratefully received.

[bigcol]

Getting into the area is very difficult, I may possibly be able to dry down tube a bit more, and paint some anti rust treatment on the tube

I have got a new tube of foam, but don't think it make much diference because of the tank.

You would have thought that the tank be covered with insulation foam wouldn't you.

Sitting here on the bed, can feel the cold air,coming through, but at least it's circulating, good thing?

 

Last year, made things happen to get the bedroom a lot warmer, now opened up the hatch to the bow now lol

Got to smile!!!