Dealing with condensation.... No shore power.

[jimbouy]

Now we've had some seriously cold weather I'm getting some condensation on board my Centaur.

Not having shore power means it can't be dealt with via a dehumi' machine, mores the pity.

So I guess ventilation is the answer. Currently there's a grill in the wash boards and the forward hatch has a ventilator of sorts.

Any suggestions for improving the situation.

I wondered about making up a wash board with 2x 12volt fans in it and powering them from a solar panel.

All sensible suggestions welcome.(That's asking for trouble.)

Jimbouy

 

[jsl]

I have a wedge-shaped box which locks over the partly-open forehatch. There is a grille in the thick [aft] end of the wedge, and gaps where the box meets the deck. Result: big apparent reduction in condensation.

 

[doug748]

Are you ashore? If so dismantle all the sea cocks and leave open. Arrange the forehatch so it is just open a tad (but locked, I use a padlock on the stays). Pad the cockpit lockers so they are just open a chink. If possible fit a cockpit cover. I have experienced few problems with this method over the years. Brian.

 

[AndrewB]

To stop condensation basically you have to make sure (i) there is never a major temperature gradient between the inside and outside surfaces of the yacht, which is most likely to occur just after nightfall; (ii) the air inside is not at high humidity, which is most likely if you are living aboard, cooking or using a 'wet' heater like gas.

Its tricky on a mooring. Ventilation helps prevent both a big difference in temperature, and a build-up of humidity inside. Insulation is also good for the former, we have reduced condensation very effectively this way.

Someone is going to recommend 'crystals'. They don't work, unless perhaps you can change them several times a week.

 

[tcm]

Re: avoiding damp damage

the damp wet air is heavier and sits in the bottom of the boat. Taking out the log paddle wheel and it all falls out- i checked with a cigarette and there's quite an airflow tearing out of the boat.

the other thing of course is to unload the boat- get everything textile/linen that you can possible get out into your car and back home in central heated house. Everything, matresses, carpets curtain the lot. leaving just empty boat. And the textile stuff is expensive to replace.

Those things that you can't get out or for which there is no room, need squishing to get the (damp) air out and ramming into an upper cupboard- again, away from the damp air.

Mattresses are often a bit too big to get out, so if impossible, again think of the airflow - the damp air would sit on a flat surface- so stackem up, perhaps at an angle, up on a berth so the air flows off and away. A good spot for midew is at the interface between warm mattres and colder surface, so jack up thhe matresses with bitos of wood and so on to get a gap underneath, again so the damp air can flow off the matress rather than sit on it or get trapped under it.

Curtains especially need to be away from the windows where most condensation takes place and hence most mildew etc. pull them well away from windows, often they can be unhooked and stashem or take home, otherwsie use carboard to blan kthe windows and avoid sun damage on the same spot every day - and reduce condensation risk.

Finally, everything metal/shiny needs a squirt and a wipe with WD40. Non-marine things like hinges and taps and some lightswiches will otherwise take a bit of rust. Even crappy knives and forks can be susceptible. Again, the things that are most at risk are those low down in the boat - you hardly eer see rusty light fittings in a boat. Here endeth the sensible advice.

Another (but unfortunately much more stupid than above) idea which would alleviate condensation would be to displace all the cold air by filling the boat with something else, like er well perhaps polystryrene packing chips? Not sure how you would get rid of these, so they would end up a bit permanent, and although nice and warm, i suppose it would get a bit tiresome having to swim through a sea of the stuff and be permannetly spitting out bits of polystyrene. So, use the larger curly ones would be best to avoid them going up your nose.

 

[cameronke]

Hi Jim
You can get non-powered dehumidifiers from most hardware stores. They work by using a hygroscopic salt (ever noticed how salt absorbs moisture from the air?) When they are done, you simply buy a refill.

Regards
Cameron

 

[jimbouy]

oK. This sounds good.... I'll have to take a look and see if I can see away of making a secure wedge.


Jimbouy

 

[jimbouy]

Interesting that you feel a cockpit cover helps. I guess it keeps the damp away from the companion way etc.

 

[jimbouy]

Re: avoiding damp damage

Just about everything textile is off the boat. Cushions are vinyl covered and I leave them propped up and the locker covers off.

I'd like to try leaving out the log paddle wheel but i think that will make matters worse as she's in the water!!!

The worst of the condensation is forming in the heads and hanging locker which are both bare at the moment. (see my previous decorating post) so perhaps i have to think of something other than just painting them so as to provide a bit of insulation. (Trouble is the budget is already way over!!!)

All food for thought tho.

 

[Stemar]

Re: avoiding damp damage

If the condensation is localised, it might be worth trying to insulate these areas.

Self sticky cork tiles are one way to go - you can even get them prevarnished, and they're flexible enough to fit on simple curves. Double curvature is a bit more difficult, but can be done - experiment with thin card to work out how best to do it.

If you don't like the colour, just paint 'em

 

[AndrewB]

[ QUOTE ]
Interesting that you feel a cockpit cover helps. I guess it keeps the damp away from the companion way etc.

[/ QUOTE ]Covers help not because they keep damp air away but because they act like insulation, in reducing the temperature gradient on the skin of the boat. In the north-east US with plumetting night-time temperatures it is popular to shrink-wrap yachts in winter - particularly for liveaboards.

 

[tcm]

Re: avoiding damp damage

welll, heads are usually a bit plastic/waterproof so condensation needn't be a massive prob. Wd40 as above. You can tell the age of many boats by the condition of the mooring lines and fenders on the outside (most boats never ever replace them) and inside by the mankiness of the taps in the heads, so if the tap(s) goes a bit oxidised, buy a new one! Lots of boats for sale call this a "refit"

 

[jimbouy]

Re: avoiding damp damage

Funny that I've just done a search on cork. I note that it can absorb moisture, but I guess the answer is to use the prevarnished and finish off with one more coat of varnish.

Cork would remind me of my decoration habits in the 80's.

 

[kandoma]

Re: avoiding damp damage

mmhm, nobody recomanded the solar powered airvents. I would try them first.

Peter

 

[doug748]

A close fitting cockpit cover does keep the wet away from the cockpit areas, and locker lids always seem to leak a little (esp if you have propped them open for ventilation). My boat came with a cover, I was not at first impressed, but am now a firm convert; it helps keep prying eyes and fingers at bay and keeps the cockpit cleaner.

 

[roger]

I've found that a cockpit cover makes it much more pleasant to work on the boat because its warmer. The cover, particularly a clear one, can act as a greehnhouse. The free heat with good ventilation will help to get the boat dryer and of course protects from leaks