Mould while cruising

lustyd

lustyd

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Looking for sensible suggestions for stopping mould while cruising.
Dehumidifiers aren’t practical and airing doesn’t work. We regularly clean with bleach/vinegar and it’s just not working and starting to feel like a full time job.

Obviously we could turn south, but Scotland was first on our list. Do we just need to put up with it for the season and then accept that cruising north isn’t practical without bringing a full time cleaner?
 
This is curious? Why are you getting mould? My GK24 in Inverness doesn't have any mould, even after being left for weeks at a time 'shut down', and without any hatches left open, or airing of any sort. My previous boat, a wooden Folkboat did suffer from mould if left alone, but not when I was cruising and living aboard, and she was a (very) wet boat, with continuous moisture ingress (leaks) from the hull, whereas the GK24 is absolutely bone dry.
No help at all to you I know, but if you're aboard and mould is appearing, then that's a mystery to me also.
 
lustyd said:
Looking for sensible suggestions for stopping mould while cruising.
Dehumidifiers aren’t practical and airing doesn’t work. We regularly clean with bleach/vinegar and it’s just not working and starting to feel like a full time job.

Obviously we could turn south, but Scotland was first on our list. Do we just need to put up with it for the season and then accept that cruising north isn’t practical without bringing a full time cleaner?
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I doubt if there are any anti-mould substances that are safe to use in a confined space, so I think that you are stuck with just ventilation.

And don’t breathe while in the boat of course.
 
Where is it appearing? Is it due to condensation or water ingress? If airing doesn't work, what about heating?

Condensation can be countered to a certain extent with self-adhesive insulation. I did charter an old Sun Odyssey near Oban and the backs of all the cupboards were black with mould due to what appeared to be condensation on the inside surface of the hull. The boat was generally damp - obviously a common problem in damper northern sailing grounds.
 
Baggywrinkle said:
Where is it appearing? Is it due to condensation or water ingress? If airing doesn't work, what about heating?
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In loads of places. In the shelves in the front cabin but also just if we leave a bag on the vbirth for a week it starts. Unfortunately our vbirth is quite full due to living aboard which makes it worse.
Yes we do use the heating and do ventilate a lot. Zero water ingress aside from wet shoes, bags, coats and occasionally towels out of necessity but all left in bathroom to dry
Baggywrinkle said:
Condensation can be countered to a certain extent with self-adhesive insulation. I did charter an old Sun Odyssey near Oban and the backs of all the cupboards were black with mould due to what appeared to be condensation on the inside surface of the hull. The boat was generally damp - obviously a common problem in damper northern sailing grounds.
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Yes it’s definitely more problematic in Scotland than south coast. At this time of year the boat would have zero condensation on south coast but we left in March and headed north so it’s been constantly damp
 
I dunno

Hot air heating . Use it.
Hand towels under the spray hood to dry not inside the boat
Sleep with adequate bedding and hatches cracked open enough to ensure a through flow of air.
Scotland !
Look at other full time cruisers I guess
It’s entirely manageable if not preventable but it is indeed a blurry nuisance!
 
I dunno

Hot air heating . Use it as a tool.

Hand towels under the spray hood to dry not inside the boat

Sleep with adequate bedding and hatches cracked open enough to ensure a through flow of air.

Scotland !

Look at other full time cruisers I guess

It’s entirely manageable if not preventable but it is indeed a blurry nuisance!

Oh, declutter 😂 yeah right - how many on board?
 
Two on board a 36 footer so decluttering isnt an option really. We need enough clothes to deal with Scottish weathers of all kinds, often all in one day.
We do use the heating quite a bit, often with windows open to dry out. We hang towels outside when practical but the flip side of that is showering and cooking every day and no power for a dehumidifier
 
We have cruised Ireland many times, never had mould. Condensation, yes, but never mould. We also sleep aboard in the wintertime on our home berth. As we have shorepower, I run a compressor dehumidifier during the night which stops any condensation. I block the dorade vents into our cabin with tea towels to ensure we are not dehumidifying the whole Harbour. However, during a six week period in the Clyde we experienced tempreture as low as 7 degrees C !

So much wet and mist we sailed to NI via the IOM for a warm up!
 
lustyd said:
We hang towels outside when practical but the flip side of that is showering and cooking every day and no power for a dehumidifier
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We don't live aboard, but don't get massive condensation issues in Scottish summers even with 4 people aboard a smaller boat for 2 weeks - but we almost never shower on board (our water tanks aren't big enough, the heads is a bit cramped and everything gets soaked in there).

Every morning we go round with a sponge and remove all condensation from hatches, portlights and other surface that are obviously wet. A karcher window vac might be worth considering if the heads is regularly getting wet. We have "desicant bags" hanging in lockers. Breathing is a big source of condensation but cooking is probably worse. An entire Camping Gaz 907 cylinder will produce about a gallon of water in its fumes if it condenses before it gets out the boat, but steam from kettles/pans etc is probably worse - obviously use lids, and plan to minimise boiling water/waste but I'm guessing you are doing that anyway.

In your shoes, I'd be looking at how you might get some sort of "occasional" dehummer. Even if it was only when you occasionally go to a marina a decent one should have quite an impact - especially if you were closing the boat up and leaving it to do its thing whilst you were ashore. Not sure how much power you have - but smaller dehummers which might be more practical for storage will run on ~ 200W or less. Excess power is a luxury you might not have, and no doubt you want it most when its wet outside so solar is limited. Getting the boat "completely" dry to start with then I think you should be able to get it under control.
 
Don’t use the heater regularly, not all the warm moist air will get changed and items will heat up and trap more moisture in them, if there are a lot of items in storage.
Never put the hatch boards in when sleeping to allow high volume air changes.
Sleep with hatches at least on the first stop (about 1” gap), all hatches.
A full fore cabin of stuff could be a big source of moisture traps, especially from damp sails and toys like SUPs, if you have them. Get stuff on deck when moored, at anchor.
Cook with overhead hatch open, or main companionway open.
If you have a full cockpit enclosure, take it down, it is another source of trapped moisture air.
Fit stronger extraction fans in the heads if showering to extract air. Shower less and use wet wipes, flannel washing for hygiene as a substitute.
Shallow bilges that can accumulate water, are a large surface area and can contribute to high moisture contents, for not a lot of water volume, keep dry.
Salt water damp items, or even saltwater dried items, need to be cleaned with fresh water and dried or they will continue contributing to damp levels.
If there are cushions in the forecabin, consider removing them if it is only being used as a store, or drying and sealing in plastic if you will need them later.
Have less sex or more outdoor sex, but make sure you have tick tweezers available. This is a joke, the sex, the tick tweezers you must carry.
The frequent water, bleach, vinegar washing could be introducing water vapor, compared to just wiping down and drying damp surfaces.


It’s not something that gets reported on a lot, so I am wondering, if your moisture raising activities are excessive. I used to work on a sail training vessel (Clyde and West Coast) and significant ventilation was used to keep damp down. Sails at every opportunity were removed from the forecabin area and placed on deck to dry. Carpet linings, cloth linings don’t help either. Smoother surfaces allow drying. Cleaning regularly was also a chore that had to be done, as dust and dirt builds up due to frequent use.

Regarding the hatches, when it is just my wife and I sailing, when moored, anchored, the hatches are all open. If sailing with friends, they close the fore hatch and the difference in odor and dampness, just over a weekend is significant.

When I leave my boat, all the hatches are on vent setting, and air flows through the boat. While a dehumidifier could help, I suspect that some changes to boat husbandry, might be more beneficial.

Good luck with your efforts.
 
Insulation has been mentioned but not emphasised enough. Its likely to be very important

The Sailing Florence refit for the arctic episodes details an insulation programme which seems to have been pretty effective in Scotland.

Ventilation has been mentioned but not emphasised enough. Its likely to be very important.

This might mean installing dorades, using fans, and keeping hatches open when ever possible. The last action might be assisted by spray/rain covers for hatchways, and maybe even wind scoops.

Toughening up has not been mentioned but is likely to be of key importance, being required to implement sufficiently aggressive ventilation, for example. Basically if you are not heating you should be aggressively ventilating. Much of this is likely to be mental rather than physical toughening, For example, having spent a winter sleeping in my car while doing an MSc at Aberdeen University, I know that, with adequate bedding (and perhaps a hot water bottle) this isnt an actual physical hardship, but after 20 years in SE Asia I'm not so sure about the actual sailing in Scotland, or the winter yardwork.

Attention to detail in preventing tracking water in, stopping leaks, mopping up free water and treating mold with bleach is likely be an omgoing requirement even with all that lot.

Sponge baths, perhaps sit-down on the toilet (all I have headroom for anyway) puts A LOT less water in the air than a sprayhead
 
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I've had mould on other boats, often down quarterberths and on uninsulated surfaces. Much already said about ventilation, insulation and air movement.

My current 36ft boat has a big internal volume, usually has one or two aboard and we don't shower on board except using an outdoor solar shower. And I can still occassionally find mould traces in hidden sleeping cabin corners after weeks living on board. Lockers are OK.

I air bedding when I can and lift the mattress on a hot day to air the base (I have an air circulation liner beneath it).

My (large) engine and calorifier are under the saloon floor and hold their warmth for 12+ hours which I suspect helps keep the air dry. Towels and anything wet are dried pegged outside or under the sprayhood.

Interestingly I get more mould at home than I do on the boat.....!
 
Get some Flash & dilute with water. Put in a spray bottle & apply a fine spray to the areas that suffer the most.
Then wipe with Flash wipes soaked in a Flash/ water mix such that the moisture is not fully removed.
Some needs to remain & evaporate.
That leaves a mould killing chemical on the surface even though it does not solve the condesation issue.
Every time you wipe dry use some paper wipes with Flash in them
That should at least prevent mould
 
ylop said:
we almost never shower on board (our water tanks aren't big enough, the heads is a bit cramped and everything gets soaked in there).

Every morning we go round with a sponge
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More environmentally friendly than wet wipes, but you’d definitely want to clean that sponge well afterwards.

Edit: I’ll get my coat…
 
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