So I have a mildew problem. With colder and wetter weather these last few weeks I went from a mildewy smelling interior to outright visible mold in places. So, I purchased a dehumidifier. It's been going about 3 days now with no noticeable result. My test was a pair of damp sailing gloves left in the boat that were still damp after three days. Anyone out there have a good solution to this? How do you keep your boat dry and mildew free while it is stored?
Preventing Mold and Mildew
- Thread starter markwbird
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Then do a search here on mildew and read for weeks.
We have a boat in Alameda, and don't have any problems.
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Then do a search here on mildew and read for weeks.
We have a boat in Alameda, and don't have any problems.
I'm not sure where you are located but I'm here in the Pacific Northwest and it is damp--all the time. But for the past twenty five years I have had no mildew, mold or dampness in my boat during the winter months. In fact my last five boats (all new Hunters) have never had a problem.
I use two silver disks from West Marine that just blows air. No heat, just air. And I use a Milk House heater for when the temperature goes below forty degrees. I don't move cushions or mattresses or even sleeping bags. But one disk is in the back cabin and one disk is in the main cabin.
About once a week I do go down to visit my boat and turn on the Webasto hot air furnace and bring the temperature up to the sixties. However, I have been know to leave the boat to itself for several weeks at a time. Still, no mildew.
But a caution. I do not live in a high humidity area. Damp but not high humidity. That might make a difference.
I use two silver disks from West Marine that just blows air. No heat, just air. And I use a Milk House heater for when the temperature goes below forty degrees. I don't move cushions or mattresses or even sleeping bags. But one disk is in the back cabin and one disk is in the main cabin.
About once a week I do go down to visit my boat and turn on the Webasto hot air furnace and bring the temperature up to the sixties. However, I have been know to leave the boat to itself for several weeks at a time. Still, no mildew.
But a caution. I do not live in a high humidity area. Damp but not high humidity. That might make a difference.
1. How large of a dehumidifier did you get? 40 pt 70 pt?
2. If it still smells, then you probably need to recondition the interior.
You have not had that much rain so I would start with a clean interior and make sure the unit is left running 24x7. Do you need to empty a built in bucket or do you have a external drain? We are in the delta and leave ours on 24x7 from Nov/Dec through April. We also leave a couple of clip on fans going too. For places like closets you can use the hang-up Damp Rid. .....and like Stu Man said vent-o-late.
2. If it still smells, then you probably need to recondition the interior.
You have not had that much rain so I would start with a clean interior and make sure the unit is left running 24x7. Do you need to empty a built in bucket or do you have a external drain? We are in the delta and leave ours on 24x7 from Nov/Dec through April. We also leave a couple of clip on fans going too. For places like closets you can use the hang-up Damp Rid. .....and like Stu Man said vent-o-late.
Stop all water ingress, liquid and vapor.. dry the bilge.. close off the scoops just forward of the companionway... THEN put the dehumidifier in..use a 30 pint capacity unit, or thereabouts.. circulate the air with small fans .. I have two of these that run pretty much continuously; one in the vee, one in the aft cabin.
http://www.walmart.com/ip/QV-Tools-Table-Fan/39889207
I have done this for over 20 years on my 34 here in South Louisiana..
I used to have a big dehumidifier that I secured on the counter so it would drain into the sink.. now I use the air conditioner set on its "dehumidify" cycle.
EDIT; Steve beat me to it.. pretty much same answer.
http://www.walmart.com/ip/QV-Tools-Table-Fan/39889207
I have done this for over 20 years on my 34 here in South Louisiana..
I used to have a big dehumidifier that I secured on the counter so it would drain into the sink.. now I use the air conditioner set on its "dehumidify" cycle.
EDIT; Steve beat me to it.. pretty much same answer.
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Mildew and other fungals propagate by spreading of their spores. If there is mildew already on your boat, the mildew will continue. If you have a CLEAN boat, including 'clean' in all the hidden places such as behind 'boat liners', blind panels, under the sole, bilge, etc. there wont be many spores there able to propagate and spread to new areas.
Mildew spores dont readily grow on 'alkaline' surfaces; that's why your ancestors 'white-washed' just about 'everything'.
3M Mildew Block is a modern equivalent of 'white-wash'. So too is spraying on a heavily caustic detergent and simply let it dry ... but not on varnish or on painted surfaces or it will 'lift' the coating. http://www.amazon.com/3M-Marine-Mil...540138&sr=1-1-catcorr&keywords=mildew+blocker
Mildew thrives on 'acidic' surfaces ... surfaces that are neutral to mildly acidic when wet.
The application of vinegar will sometimes generate a surface acidity greater than that on which mildew, etc. can start, thrive, or live. However, when that acidity dilutes itself over time that 'vinegared' surface may now be at the 'perfect' acidity to make mildew, etc. REALLY thrive.
There are some powerful off-gassing chemicals (available in those states where most 'consumer' chemicals are not banned) that can be added to a closed up boat or space that directly attack and destroy mold/mildew and their spores. Many of these are available in 'boat chandleries' in those states that allow. ParaFormaldehyde and equivalent crystaline form chemicals .... Brand Name is "MildewGaz". Dont breathe these (off) gases as they can also be very dangerous to lung tissues; always let any closed space where these 'crystals' are placed fully 'air-out' before entering.
Note on cleaning molds/mildews -- NEVER clean mold or mildew when its DRY as this will release the spores into the air and many of these are very dangerous to lung, etc. tissue. Always 'wet' (spritz) and let soak molds/mildews/fungals before any attempt at cleaning to prevent the spreading of the spores. Use CAUSTIC detergents which will dissolve mold/mildews and their spores - spritz on and let soak/dissolve, etc.
ALWAYS use a 'mask' or respirator when cleaning spores!!!!
Mildew spores dont readily grow on 'alkaline' surfaces; that's why your ancestors 'white-washed' just about 'everything'.
3M Mildew Block is a modern equivalent of 'white-wash'. So too is spraying on a heavily caustic detergent and simply let it dry ... but not on varnish or on painted surfaces or it will 'lift' the coating. http://www.amazon.com/3M-Marine-Mil...540138&sr=1-1-catcorr&keywords=mildew+blocker
Mildew thrives on 'acidic' surfaces ... surfaces that are neutral to mildly acidic when wet.
The application of vinegar will sometimes generate a surface acidity greater than that on which mildew, etc. can start, thrive, or live. However, when that acidity dilutes itself over time that 'vinegared' surface may now be at the 'perfect' acidity to make mildew, etc. REALLY thrive.
There are some powerful off-gassing chemicals (available in those states where most 'consumer' chemicals are not banned) that can be added to a closed up boat or space that directly attack and destroy mold/mildew and their spores. Many of these are available in 'boat chandleries' in those states that allow. ParaFormaldehyde and equivalent crystaline form chemicals .... Brand Name is "MildewGaz". Dont breathe these (off) gases as they can also be very dangerous to lung tissues; always let any closed space where these 'crystals' are placed fully 'air-out' before entering.
Note on cleaning molds/mildews -- NEVER clean mold or mildew when its DRY as this will release the spores into the air and many of these are very dangerous to lung, etc. tissue. Always 'wet' (spritz) and let soak molds/mildews/fungals before any attempt at cleaning to prevent the spreading of the spores. Use CAUSTIC detergents which will dissolve mold/mildews and their spores - spritz on and let soak/dissolve, etc.
ALWAYS use a 'mask' or respirator when cleaning spores!!!!
Mark,
I'm not that far from you, so the weather is the same. We had the same issues with visible mold and odor for quite a while. We never did go the dehumidifier route, but rather like the previous posters indicate, the key is ventilation and keeping the interior dry. Once that happened, no more mold/mildew and no more smell.
Specifically I did the following (not necessarily in order):
* Cut the bottom out of the bilge sump area to expose the gap between the inner liner and the actual hull. This allows you to mount the bilge pump on the bottom and evacuate stinky water that accumulates. Always use a sponge and soak up the remaining water in the bilge and under the shower sump before you leave.
* Leave the small starboard hatch over the head open always about 1 1/2 - 2 inches. We drape the shower curtain over the toilet. Even with rain, we really don't get water in there anyway. You need that air to flow into the boat.
* I bought a 12 volt computer fan at an electronics store in Milpitas for $4.00 and put it inside the wood panel under the dorade vents in the main salon. I bought a 5 watt solar panel and put it in front of the dorade vents topside. Fish the wire in one of the vents and hook it to the fan. Now it runs whenever the sun is out. Face the dorade vents back.
* I bought a second fan and stuck it in the Beckson port down by the engine where you reach through to check the oil. That one I wired directly to the back of the battery selector switch. Since we leave our boat plugged in to shore power all the time, the fan stays on always as well. I put some dryer vent hose on the Beckson port and exhaust it out the port hole directly above. This one I am going to improve shortly.
* Leave the locker doors open and even prop the cushions up and pull the access panels to get air inside everywhere.
As long as you have the inside temperature the same as the outside temperature by ventilating, you won't have condensation and the mold/mildew won't keep forming. De-humidification won't be necessary. As it is if you pull moisture out of the air in the boat, its just going to be replaced by more moist air anyway. Keep the air moving and dry out the wet spots. It will clear up, but it will take a little while.
As above, clean up the existing mold/mildew carefully. A mild bleach solution is caustic, just be careful with its application. You'll have to air out the cushions when you can.
Send me a PM on the site and I will be glad to share any other tips we have picked up with this issue.
I'm not that far from you, so the weather is the same. We had the same issues with visible mold and odor for quite a while. We never did go the dehumidifier route, but rather like the previous posters indicate, the key is ventilation and keeping the interior dry. Once that happened, no more mold/mildew and no more smell.
Specifically I did the following (not necessarily in order):
* Cut the bottom out of the bilge sump area to expose the gap between the inner liner and the actual hull. This allows you to mount the bilge pump on the bottom and evacuate stinky water that accumulates. Always use a sponge and soak up the remaining water in the bilge and under the shower sump before you leave.
* Leave the small starboard hatch over the head open always about 1 1/2 - 2 inches. We drape the shower curtain over the toilet. Even with rain, we really don't get water in there anyway. You need that air to flow into the boat.
* I bought a 12 volt computer fan at an electronics store in Milpitas for $4.00 and put it inside the wood panel under the dorade vents in the main salon. I bought a 5 watt solar panel and put it in front of the dorade vents topside. Fish the wire in one of the vents and hook it to the fan. Now it runs whenever the sun is out. Face the dorade vents back.
* I bought a second fan and stuck it in the Beckson port down by the engine where you reach through to check the oil. That one I wired directly to the back of the battery selector switch. Since we leave our boat plugged in to shore power all the time, the fan stays on always as well. I put some dryer vent hose on the Beckson port and exhaust it out the port hole directly above. This one I am going to improve shortly.
* Leave the locker doors open and even prop the cushions up and pull the access panels to get air inside everywhere.
As long as you have the inside temperature the same as the outside temperature by ventilating, you won't have condensation and the mold/mildew won't keep forming. De-humidification won't be necessary. As it is if you pull moisture out of the air in the boat, its just going to be replaced by more moist air anyway. Keep the air moving and dry out the wet spots. It will clear up, but it will take a little while.
As above, clean up the existing mold/mildew carefully. A mild bleach solution is caustic, just be careful with its application. You'll have to air out the cushions when you can.
Send me a PM on the site and I will be glad to share any other tips we have picked up with this issue.
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From the responses, it looks like there is no easy way out of this. Based on Rich H's response I may just set the boat on fire and get out my golf clubs. Actually, the visible mold is on the wood in the interior. My concern is that any cleaning agent will mar the finish. It's sort of a chicken/egg thing. I am willing to clean every surface and wash every fabric but only after I have a system in place to prevent the mold from coming back. The two basic solutions are a little bit contradictory. Ventilation vs dry out. You can't really dry the air without closing up the boat. Berkeley is a cold, damp climate this time of year. The water is cold so the hull below the waterline stays cold all the time attracting some condensation even in warmer weather. Your thoughts?
Thanks Allen for the great info. It looks like you and I are in the same boat (I'm laughing out loud right now). You have gone to some trouble to address this issue. I am leaning toward the ventilation solution as well. Thanks all for the help.
I forgot about Fire. That's always a good way to get rid of mold.
We had the same mold on the wood. We used the Clorox spray cleaner, then fresh water wipe down followed by the application of Lemon Oil. No problem with the appearance of the wood.
You don't need to dry the air. Our humidity around here is pretty low, even when its raining (the air between the drops is dry). Our water may feel cold, but at 51 degrees in the winter, it is actually warm. Its warmer than the air, so that doesn't lead to condensation. Only when our bodies are in the boat exhaling warm humid air is there significant condensation.
I forgot, with the absence of fans, you can also leave that opening port in the rear stateroom open (next to the cockpit footwell) for some good flow through. I think its pretty shielded from rainwater splashing in. Once you wipe down the mold and have air moving it doesn't come back.
How's your stuffing box? When the engine is off, it doesn't drip too much I hope. Just another source of dampness. I changed mine to the PSS dripless system. Its not a requirement, just something I did a few years ago.
I check the stuffing box pretty regularly. No sign of leakage yet. I have been considering removing the false bilge as you have done. This is a common mod for this boat. You used a hole saw which looks ideal. So, is there enough space under the false bilge so that the drill bit does not punch through the lower bilge?
Right underneath the fiberglass is a 1/2 inch thick piece of plywood which is going to be nice and rotten. Then there is another 1/4" gap. Are you familiar with the vibrating multitools? They didn't have them when I did mine, hence the 4" hole saw. Harbor Freight has the multitool for about $29.00. Get 3 or 4 of the half round blades and it should cut out in one piece. The hull thickness underneath is 1-3/8" thick so you can fasten your bilge pump with some real short screws.
Good thread. I am fairly new to boat ownership and have been curious about this too. I have an Oday 302 and last winter left one of the hatches cracked all winter and didn't notice any problems. I am curious Rich if you think I need to do more? I am up in the Annapolis area and getting ready to pull the boat for the winter. I won't have access to shore power while it is on the hard, so wiring up a fan may not work.
I am currently looking into a solar powered fan mounted in a forward hatch. They will pull about 1000 cu-ft per hour of air through the boat. No shore power required. The downside here is that, based on what I've read, these fans are not all that durable. They don't last very long, maybe two years. It's better than mildew.