Lockers full of humidity - unusable in winter

simonfraser said:
i have fitted computer fans in all the locker sides and one fan to extract air, solar panel on the roof, no damp

(dont live on my boat)
Click to expand...
Do you have a link to the fans and solar panel - I am thinking of doing this but am bamboozled by all the panel and fan types, and how to connect them all!

Thanks
 
Dessicant type dehumidifier is better for use in cold weather and less prone to spontaneously combusting apparently. I live on my boat FT & it would be horrible without a good dehumidifier (and an electric blanket!)...
 
Just come back from my boat after 2 nights onboard. Really bad condensation this morning from cooking, etc. Temperature going from mild to chilly and lots of rain meant boat a bit sealed up to keep warm. Managed to dry out a bit in the sun with some windows, etc open this morning.
I suspect that I may invest in a small dehumidifier to assist when glamping on board as constant rain means I struggle to dry the boat. At least she felt dry when I went down so not to many leaks !
I would hate to live on board at this time of year finding just a few nights enough.
 
I am indeed living aboard, so I know this is contributing to the issue, but the cabin itself is fine, that is not an issue. I am talking about inside the lockers and behind cushions touching the hull or are above the watertank (naturally cold surfaces in the winter)

Generally the boat is dry, just those spots are not. I can't put anything in the lockers under the seat because they are all touching the hull, and condensation just builds up and gets everything wet and after a while mouldy.
 
Ime with the ventilation and even more ventilation brigade. As a heating engineer I have a little knowledge on the subject . Also when aboard try to keep moisture levels down , like open hatches fully when cooking / boiling kettle etc.. the hardest area to keep dry is the forepeak as its difficult to vent on my boat so its cushions proped up as soon as possible. Lockers seem to keep dry on mine so maybe you do have water ingress . I even try to ensure all lines are dry before storage as they can hold a humongous amount of water and thats got to go somewhere.
Edit...
My apologies ime referring to cockpit lockers ...even these are dry.
 
I have lived aboard both steel and GRP boats, the first in lat 60N, the second at 59N. Water temps around 10C, frost or snow on deck at times.

As many have said the answer is insulation of all external surfaces to the lowest deck level, so only bilges exposed to condensation. I have never used a dehumidifier on any boat, just ventilation and heating. The lower the heat source the better as the cold moist air accumulates there. Never had mould on the boats and kept bedding, clothing, etc. onboard all year round.

Now in warmer climes and just sold my last boat. I always ran a low wattage heater at the lowest level in the cabin during the winters when the boats were empty, even though in warmer climes now with winter sea temp around 17C, often warmer than the air temp. The couple who bought the boat commented afterwards that it was the only boat they looked at here that did not smell of damp or mould inside - despite the fact she had obviously been neglected for three years due to ill health and had some rain drips from the window frames.

Insulation, ventilation and a gentle source of heat are the key factors.
 
Whatever you do, ventilate, insulate or dehumidify, you are not going to know if it's working unless you can measure it. You can buy digital humidity meters for about a fiver. Buy a few and spread them around, if the relative humidity goes above 70% you will have condensation and mould.
 
I don’t believe that there is a solution that suits all boats and all areas. As I see it, you either ventilate or dehumidify. In theory, a dehumidifier should solve all problems, but we find it necessary to leave lockers open and bedding and upholstery tilted up. I use granules in the cockpit locker because some electrics are in there.
 
srm said:
I have lived aboard both steel and GRP boats, the first in lat 60N, the second at 59N. Water temps around 10C, frost or snow on deck at times.

As many have said the answer is insulation of all external surfaces to the lowest deck level, so only bilges exposed to condensation. I have never used a dehumidifier on any boat, just ventilation and heating. The lower the heat source the better as the cold moist air accumulates there. Never had mould on the boats and kept bedding, clothing, etc. onboard all year round.

Now in warmer climes and just sold my last boat. I always ran a low wattage heater at the lowest level in the cabin during the winters when the boats were empty, even though in warmer climes now with winter sea temp around 17C, often warmer than the air temp. The couple who bought the boat commented afterwards that it was the only boat they looked at here that did not smell of damp or mould inside - despite the fact she had obviously been neglected for three years due to ill health and had some rain drips from the window frames.

Insulation, ventilation and a gentle source of heat are the key factors.
Click to expand...
For a while I was thining about routing the ducting from a diesel heater though all the lockers
 
Thresher said:
Whatever you do, ventilate, insulate or dehumidify, you are not going to know if it's working unless you can measure it. You can buy digital humidity meters for about a fiver. Buy a few and spread them around, if the relative humidity goes above 70% you will have condensation and mould.
Click to expand...
That's a good plan
 
Look at some old construction drawings from the days of wood boats. Designers and builders then were well aware of the importance of through ventilation in order to prevent rot growing and destroying the boat's structure. Lockers usually had ventilation by louvered doors or other means. Once GRP came along it was assumed that ventilation was simply a matter of opening a hatch or window. The structure may not rot, but the contents can.

As an aside, we live in a place with naturally high humidity, way out in the Atlantic. When renovating our house I specified louvered doors for all kitchen cupboards and ventilation slots for the drawers after hearing about other people finding mould growing in their units.
 
I was taught that mould only grows on a damp surface in totally still air. You don't need much air movement to create enough flow to eliminate mould. My solution is to have a solar powered vent at one end of the cabin, and small standard vents at the other, and also placed where air will be drawn through the lockers. I tried a similar approach in my greenhouse using a 12V computer fan that cost little more than pence, which also worked. The condensation will also reduce if the inside air temperature is the same as outside, which is OK on stored boats but not so much fun in a liveaboard.
 
All of the others have made good points about ventilation etc but one thing you could do is to keep clothes, towels and other things etc in those plastic storage bags with ziplock seals. That's what I do - admittedly it doesn't solve the problem of condensation in the lockers but it keeps the things dry and usable and they don't go mouldy.
 
salar said:
I was taught that mould only grows on a damp surface in totally still air. You don't need much air movement to create enough flow to eliminate mould. My solution is to have a solar powered vent at one end of the cabin, and small standard vents at the other, and also placed where air will be drawn through the lockers. I tried a similar approach in my greenhouse using a 12V computer fan that cost little more than pence, which also worked. The condensation will also reduce if the inside air temperature is the same as outside, which is OK on stored boats but not so much fun in a liveaboard.
Click to expand...
Sooo with the 12v computer fan I was on the right track then. I might go with that then. Maybe I cut some ventilation holes in the sides or something, too. Maybe a sliding door for the seat lockers in the salon which would solve accessibility issues too.

Need to think about power consumption for the fans then. In summer it's not an issue, but winter. Hmmm

Thanks for the advice. Like always, helpful
 
DangerousPirate said:
Sooo with the 12v computer fan I was on the right track then. I might go with that then. Maybe I cut some ventilation holes in the sides or something, too. Maybe a sliding door for the seat lockers in the salon which would solve accessibility issues too.
Click to expand...
You also need to insulate any potentially cold surfaces such as hull or cabin sides to prevent condensation. Blowing warmed air into a locker with a cold surface could increase your damp problems as the warmed air dumps moisture. In the MN its known as ship sweat and was a serious problem when cargo was stowed in holds. Now most cargo is containerised so not so much a problem for the crew.
 
Ventilation is the key.
Clean up the mould. If there appears to be a location particularly susceptible (e.g. a cold location with little air flow, try painting with anti-condensation paint. When we bought our boat 30 years ago there was one such. After cleaning and painting the mould has never returned.
 
DangerousPirate said:
I tried those little plastic ones that you put in with the silica inside or whatever it is. Those didn't work that well where I tried. Did basically nothing
Click to expand...
I use these in the lockers with the doors closed and they do work well. First set lasted a month second set has barely collected any moisture. I do, however, run a dehumidifier in the cabin while aboard to keep overall moisture levels down.
 
salar said:
I have a USB fan from Amazon (other suppliers are available) which is rated 5V so you will need a USB adaptor into 12V or mains but the good news is that it draws only 1.4W and 0.28amps
Click to expand...
That's nice. Add a couple together though for all the lockers and you do have a couple of w and amps per hour though. Well, will see what I do then.
 
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