Trad boat wet bilge.

[blake2016]

Hello fellow narrow boaters,hope some one can give me some help/input on this matter whats driving me mad,been living aboard now for nearly two years (best move ever might i say) and during summer the bilge area on my trad boat is bone dry, but come winter its soaking wet forming about 4 inches of water in the bilge also all around the weed hatch its soaking wet drips of water ever where,every 2 days i have to mop the bilge out or use the bilge pump and try to dry the walls around the weed hatch with towels surely this cannot be right,or could this be condensation due to being a live aboard,what worrys me is the fact when its dry there is quite a bit of rust starting to appear, we are marina based many thanks for the replys.

[roland elsdon]

Water has to condense somewhere, it will start where there is no insulation ( around counter utter and swim plates ) and then flow into bilges. The counter is the most exposed spot as it is neither in the water all the time nor in the air, and challenging to insulate, unless Foam sprayed

Essentially you have to reduce the water vapour of your internal air, leaving less to condense onto cold spots.

Solid fuel stoves do this by drawing internal air in and putting it up the chimney , however electric heating and non circulatory air central heating do not. Breathing showering etc all add to the water saturation.

Before foam spray insulation was common rock wall used to trap damp against poorly treAted steel, and it is not unusual for boats to rot through their cabin tops and sides from internal corrosion.

A dehumidifier may help as does good ventilation, chasing out the damp air.

In the summer clean paint and wax oil the bilge is good, but the reality is it's going to condense somewhere, and it's probably best to know where, so you can dry it up.

Wooden boats don't suffer however....

[nikvah]

4" seems quite a lot of water to be caused by condensation. I have a similar problem on my boat which, after checking and rechecking hoses and their connections, the skin tank and drain lines, I realised was due to good old English rain. Problem in the winter, not so much in the summer, falls on the unprotected counter and finds it's way onto the surface above the swim and then drips into engine bilge. I have yet to locate the small hole in the weld that I assume causes this.

[dmr]

4 inches is a lot, is this really every other day or more like once per week or whatever? Its easy to ,oose track of time when you live on a boat.

 

We have the same issue but only a mm or so each morning. Think the issue is that we sleep in the back cabin and let the back of the boat get quite cold at night, and there is lots of bare steel under the floor and at the back, round the weedhatch etc etc for the condensation to form.

I don't see an easy fix for this except for insulating all the bare steel which would not be easy. Dunno what goes on under the floorboards on most boats, if there is cold bare steel its hard to see how to avoid condensation.

 

Thing that interests me is that it kicks in very quickly over a period of just a few days, sometime in November, and stops almost as quickly in the spring. Must relate to water temperature but there is a very obvious threshold effect.

 

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

[cuthound]

4 inches is a lot, is this really every other day or more like once per week or whatever? Its easy to ,oose track of time when you live on a boat.

 

We have the same issue but only a mm or so each morning. Think the issue is that we sleep in the back cabin and let the back of the boat get quite cold at night, and there is lots of bare steel under the floor and at the back, round the weedhatch etc etc for the condensation to form.

I don't see an easy fix for this except for insulating all the bare steel which would not be easy. Dunno what goes on under the floorboards on most boats, if there is cold bare steel its hard to see how to avoid condensation.

 

Thing that interests me is that it kicks in very quickly over a period of just a few days, sometime in November, and stops almost as quickly in the spring. Must relate to water temperature but there is a very obvious threshold effect.

 

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

The threshold were condensation occurs is called the dew point, and is related to both temperature and humidity.

 

More info here.

 

https://en.m.wikipedia.org/wiki/Dew_point

 

Many years ago I did a refrigeration course. The lecturer took us into a small room containing a 1 gallon garden spray full of water, an electric heater and an air conditioning unit.

 

By heating up the air, he was able to demonstrate dry heat (fairly comfortable). He then emptied the garden sprayer intof the air. Same temperature but much more humid (very uncomfortable).

 

He then switched off the heater and turned on the air conditioning unit. The air became foggy for a while, then the temperature dropped further the water condensed out all over the floor.

 

Had the air conditioning unit been powerful enough, he cold have lowered the temperature to produce frost!

[Alan de Enfield]

Hello fellow narrow boaters,hope some one can give me some help/input on this matter whats driving me mad,been living aboard now for nearly two years (best move ever might i say) and during summer the bilge area on my trad boat is bone dry, but come winter its soaking wet forming about 4 inches of water in the bilge also all around the weed hatch its soaking wet drips of water ever where,every 2 days i have to mop the bilge out or use the bilge pump and try to dry the walls around the weed hatch with towels surely this cannot be right,or could this be condensation due to being a live aboard,what worrys me is the fact when its dry there is quite a bit of rust starting to appear, we are marina based many thanks for the replys.

 

Do you mean he 'engine room' bilge &/or the 'cabin' bilge ?

 

If you mean the 'engine room' bilge (and as you are marina based and presumably have electric hook-up) try putting a 'greenhouse' tubular electric heater in there switched on permanently. They come in various sizes (20w, 40w, 60w etc) something like a 60w would be sufficient and would only cost about 1p per hour to run.

 

Give it a try it won't have cost a fortune if it doesn't work.

 

Just as an example - not a recommendation :

 

http://www.screwfix.com/p/dimplex-ecot1ft-wall-mounted-tubular-heater-40w/3951F?kpid=3951F&cm_mmc=Google-_-Product%20Listing%20Ads-_-Sales%20Tracking-_-sales%20tracking%20url&gclid=CjwKEAiAp97CBRDr2Oyl-faxqRMSJABx4kh9F_XN5ysklefLOOakskcx3_lpsJB_Bmj8GCeMQ2eYFhoCD13w_wcB

 

40w = £18

60w = £27

[pete.i]

 

Do you mean he 'engine room' bilge &/or the 'cabin' bilge ?

 

If you mean the 'engine room' bilge (and as you are marina based and presumably have electric hook-up) try putting a 'greenhouse' tubular electric heater in there switched on permanently. They come in various sizes (20w, 40w, 60w etc) something like a 60w would be sufficient and would only cost about 1p per hour to run.

 

Give it a try it won't have cost a fortune if it doesn't work.

 

Just as an example - not a recommendation :

 

http://www.screwfix.com/p/dimplex-ecot1ft-wall-mounted-tubular-heater-40w/3951F?kpid=3951F&cm_mmc=Google-_-Product%20Listing%20Ads-_-Sales%20Tracking-_-sales%20tracking%20url&gclid=CjwKEAiAp97CBRDr2Oyl-faxqRMSJABx4kh9F_XN5ysklefLOOakskcx3_lpsJB_Bmj8GCeMQ2eYFhoCD13w_wcB

 

40w = £18

60w = £27

 

This is what I did on my boat and made a massive difference to the winter condensation. When I bought the boat there was a parrafin greenhouse heater in the engine bilge. As I wasn't comfortable with having a flame in my engine compartment and a parrafin heater tends to produce water anyway I bought a 40 watt tubular heater. I had it on a timer so that it came on at 5pm and went off at 7am. These were roughly the times that I wasn't on the boat because when I was on the boat I would run the engine and have the stove lit. I only had a 30 foot boat so the heat got distributed quite well from the stove when it was lit. It didn't stop condensation entirely especially during really cold weather but it did make a huge difference.

[Jrtm]

You could try re corking the bottom?

 

The amount your having to mop up sounds very excessive, i know my engine room gets a lot of condensation but its not enough to put 4 inches in the bildge.

 

Are you sure the seal on the weed hatch isnt leaking?

[FadeToScarlet]

You could try re corking the bottom?

 

 

You'd have a job getting it in

[dmr]

The threshold were condensation occurs is called the dew point, and is related to both temperature and humidity.

 

More info here.

 

https://en.m.wikipedia.org/wiki/Dew_point

 

Many years ago I did a refrigeration course. The lecturer took us into a small room containing a 1 gallon garden spray full of water, an electric heater and an air conditioning unit.

 

By heating up the air, he was able to demonstrate dry heat (fairly comfortable). He then emptied the garden sprayer intof the air. Same temperature but much more humid (very uncomfortable).

 

He then switched off the heater and turned on the air conditioning unit. The air became foggy for a while, then the temperature dropped further the water condensed out all over the floor.

 

Had the air conditioning unit been powerful enough, he cold have lowered the temperature to produce frost!

 

Thanks, I sort of know this stuff, though not in great detail, but why does it kick in so suddenly even though the weather fluctuates so much from day to day??? It does have wet days and slightly damp days but once its started there are very few days when there is no water at all.

The only fixed factor is therefore water temperature. I do half remember that it happened a lot less when we used to have a mooring and that was on ta river. I intended to keep a log of water and baseplate temperature this winter but failed, maybe next winter???

 

And sort of related, this summer I experienced my first "fog" in Harecastle tunnel and it was very frightening indeed, I lost all forward visibility and my headlight reflected right back at me, I briefly thought that a ghost boat was going to ram me.

 

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

[cuthound]

Consensation kicks in even though there are weather fluctuations because in winter, the temperature is generally low enough to to be staff or below the dew point. On the colder days, the relative humidity (RH) is lower, and on the warmer days it is higher (which means the dew point is higher because the air contains more moisture to condense out).

 

The solutions are:

 

Raise the temperature above the dew point by heating or insulating.

 

Reduce the RH by ventilating or dehumidifying.

[Peter-Bullfinch]

Aldi and Lidl do very cheap large packs of babies disposable nappies. We use them in winter to effectively mop up condensation in the bilge. It's amazing just how much wetness they absorb.

From time to time there are special baby week offers and the nappies are even cheaper. We buy the very largest (my goodness isn't your child out of nappies yet?) size. I can't recall the number...5?