Condensation

[Stemar]

I have a problem of condensation in lockers and engine bilges. Probably the rest of the bilge as well, but I'm not going to worry about that as I can't get to it.

In the forepeak lockers (top opening) it's so bad that a roll of toilet paper was transformed into a soggy yellow & black mush /forums/images/graemlins/tongue.gif in less than a month. Ventilation doesn't seem to help much.

Would insulating the hull inside the lockers help? I'm thinking about the stuff you get from B&Q, etc. to put behind radiators. I'm also considering lining the lockers with ply. Should I do both, one (which?) or neither.

I did cross my mind to drill ventilation holes top and bottom in the fronts, but they're sealed to the hull and come well above the waterline, so I suspect they would do some good if I managed to put a hole in the bow.

 

[fireball]

do you get the same level of condensation if you prop the lockers open?

 

[mithril]

Condensation is a real pain and it sounds like you have it bad and so I am assuming that you are aboard quite often so as to create the moist air.

Try the following 3 stage plan.

1.) Get rid of the cause of the moisture. For us its cooking as we live aboard and nearly always eat aboard so its boiling pans and the products of propane combustion. Now we open up the boat, thats as well as the weather allows, so as to loose the moist air before condensation starts.

2.) Improve ventilation. This stops moist air finding its way into still pockets and hence condencing. Quite simply, you cannot ventilate enough, and make the holes large, 30mm min.

3.) Stop the warm moist air meeting anything cold, so stopping condensation starting. This, for us means minimising the opening of lockers whilst cooking as the air is at its most moist. Additionally insulate the cold surfaces. We have used PU foam sheets as used by campers. but if you can get thicker then do so. I've recently seen a plastic laminate which has quite unbelievable U values but its £20/m as opposed to about £1 for PU foam.

Do try get on top of it as wet boats eventually smell and dont then sell.

Good luck

 

[Evadne]

You either get rid of the moisture from the air (difficult) or don't provide it with a cool surface to condense upon. As with the inside of the boat, I'd have thought insulating will cut down condensation dramatically. IMO the best would be something glued to the hull, and lid, like felt carpet tiles; ply would still allow the moisture to condense on the hull behind it.

 

[Piers]

Do you have a mains power supply? If so, use a 70.00 dehumidifier from B & Q, with its hose drain into the sink. I have done this for years with no damp/condenstaion/mould whatsoever. Keep it on a time clock for 4 hours on and 4 hours off.

 

[Stemar]

Thanks to all.

No mains power, unfortunately - on a swing.

It is better if I leave the lockers open, and really only a problem at this time of the year - I'm starting to use the boat and would really like to be able to leave the bed made up, but the water's really cold.

I think I'll insulate the lockers and see how things go from there.

 

[Piers]

Leaving cupboard doors open will certainly help.

Insulation? Try Thinsulate which is used for that specific purpose. Call Peter Furby on 07770 284 926 for further info.

 

[Abigail]

There have been various other threads on this topic over the years. The best result we've found, living aboard is to insulate the cold surfaces and keep air moving. To insulate the hull we have used 9mm closed cell foam - in fact 6mm would have done. If you have much to do don't buy the 6m mats of thinsulate as it's incredibly dear. We bought ours (a lot!) from a commerical supplier called Keeling Rubber and Plastics.

On hull sides/vertical surfaces we have covered this either with vinyl or with wood strips or with automotive carpet (from an RV fit out suppliers not a local car shop.) There is a very marked difference between those we have insulated and those not, particularly below the water line.

On non-sleeping bunks we rarely need to air insulated lockers. Under our bed we try to lift up and air once a week despite tons of insulation and air movement - obviously we breathe too much!

We use our dorade vents and also seek to open windows as soon as the weather makes this plausible. We run small dehumidifiers in aft and fore cabins and (because we live aboard and so can empty them) find these quite adequate. We have taken off the transformers and made them directly plug in to the 12v which works fine.

HTH