Ok...so I'm putting my boat to bed for the winter in the cold, wet Northwest. I've read a ton about preventing mildew, but the information is conflicting. Some say to put a little heater on board, some say don't. My current plan is to crack open a hatch in the aft stateroom and two hatches in the saloon roof, plus the boat has two fairly small dorade vents in the saloon which I will leave open as well. I will dry out the bilge and put in a small dessicant dehumidifier. I wasn't planning on any heat because when you heat air, it can hold more moisture, which results in condensation on all surfaces exposed to the outdoors. I also thought leaving the window shades up would be better since mildew doesn't like light. What do you all think? (I'll bet the answers will be contradictory, but let's see) Then again, maybe I should close all hatches and put a bunch of dessicant out...it's driving me crazy!!!
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Search for a previous thread
Scott, Search the archives for "Buckets, Collanders, & Calcium Chloride". My answer may help you and there are others in the same thread. Also, after a year's test, we have found that the application of lemon oil (ordinary stuff found in Wal-Mart) to all wood surfaces seems to eliminate the formation of mildew (the white spots). We did this last year, and found NO mildew in the spring. By the end of the humid summer, we found some light mildew on the wood surfaces that we did not wipe down or did not do very well. It was mostly inside of the cabinate under the galley sink where moisture collects. See the attached photo of the collanders and buckets. Rich
Scott, Search the archives for "Buckets, Collanders, & Calcium Chloride". My answer may help you and there are others in the same thread. Also, after a year's test, we have found that the application of lemon oil (ordinary stuff found in Wal-Mart) to all wood surfaces seems to eliminate the formation of mildew (the white spots). We did this last year, and found NO mildew in the spring. By the end of the humid summer, we found some light mildew on the wood surfaces that we did not wipe down or did not do very well. It was mostly inside of the cabinate under the galley sink where moisture collects. See the attached photo of the collanders and buckets. Rich
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Ventilation
is the best preventative. Ours is a center cocpit boat (O'Day 37) with fore and aft cabins which must be treated separately. We use three components to mildew prevention which seem to work quite well. One is low-level cabin air heaters. These are very simple, very cheap, economical to run heaters that you can pick up with your bare hands when operating. They only heat the inside air a degree or two above the outside air but they reduce the relative humidity inside the boat. And it's relative humidity you have to be concerned about, not the absolute water content of the air. Bear in mind that in cold weather the absolute water content of air drops, which is why the inside of your house is so very dry in winter and why things dry out so fast in your refrigerator. 100% relative humidity at 20F may be like 30% at 30F. (I didn't do the calcs so don't jump on me.) Mildew needs high relative humidity to start and grow. Second, keep the air moving. Passive vents don't really do the job. We have Nicro 24-hour vents on both cabins, set to exhaust. They move an impressive amount of fresh air through the boat every day. Cold fresh outside air comes in through passive vents, etc., and exhausts at the Nicros. The boat is always sweet smelling. The exhaust air is every so slightly warmer than the entering air and eve so slightly less humid. Third, open everything up so fresh air can circulate everywhere through all lockers and otherwise closed space. And finally, dump mothballs everywhere. They discourage all sorts of critters from homesteading in your boat over the winter. For what it's worth, we discovered the value of low-level heaters inadvertently. Our old boat (Dawson 26) was also a center cockpit model with separate fore and aft cabins. We had mildew in the aft cabin but not the fore cabin. The forward cabin had a portable thermolectric cooler that constantly put a barely perceptible amount of warm air into the cabin. It was enough to stop mildew. We bought an air heater for the aft cabin and that was the end of the mildew problem.
is the best preventative. Ours is a center cocpit boat (O'Day 37) with fore and aft cabins which must be treated separately. We use three components to mildew prevention which seem to work quite well. One is low-level cabin air heaters. These are very simple, very cheap, economical to run heaters that you can pick up with your bare hands when operating. They only heat the inside air a degree or two above the outside air but they reduce the relative humidity inside the boat. And it's relative humidity you have to be concerned about, not the absolute water content of the air. Bear in mind that in cold weather the absolute water content of air drops, which is why the inside of your house is so very dry in winter and why things dry out so fast in your refrigerator. 100% relative humidity at 20F may be like 30% at 30F. (I didn't do the calcs so don't jump on me.) Mildew needs high relative humidity to start and grow. Second, keep the air moving. Passive vents don't really do the job. We have Nicro 24-hour vents on both cabins, set to exhaust. They move an impressive amount of fresh air through the boat every day. Cold fresh outside air comes in through passive vents, etc., and exhausts at the Nicros. The boat is always sweet smelling. The exhaust air is every so slightly warmer than the entering air and eve so slightly less humid. Third, open everything up so fresh air can circulate everywhere through all lockers and otherwise closed space. And finally, dump mothballs everywhere. They discourage all sorts of critters from homesteading in your boat over the winter. For what it's worth, we discovered the value of low-level heaters inadvertently. Our old boat (Dawson 26) was also a center cockpit model with separate fore and aft cabins. We had mildew in the aft cabin but not the fore cabin. The forward cabin had a portable thermolectric cooler that constantly put a barely perceptible amount of warm air into the cabin. It was enough to stop mildew. We bought an air heater for the aft cabin and that was the end of the mildew problem.
Lightbulbs
Hi Scott, I feel your pain. I've always used a small ceramic heater set on "fan". That really pushes the air around but it does suck up the electricity. My landlady isn't all that keen on me using it again since she pays the electrical so this year I'll probably just use a lightbulb. It has worked ok in the past but isn't my preferred method. You should also lift all cushions, maybe blocking them up, so if any water (leaks, condensation, etc) should get under them, THEY won't mildew. I just read a neat fix for that, btw: air conditioning systems have the big bad filter that you can pick up in bulk & cut to size for each bunk. LaDonna
Hi Scott, I feel your pain. I've always used a small ceramic heater set on "fan". That really pushes the air around but it does suck up the electricity. My landlady isn't all that keen on me using it again since she pays the electrical so this year I'll probably just use a lightbulb. It has worked ok in the past but isn't my preferred method. You should also lift all cushions, maybe blocking them up, so if any water (leaks, condensation, etc) should get under them, THEY won't mildew. I just read a neat fix for that, btw: air conditioning systems have the big bad filter that you can pick up in bulk & cut to size for each bunk. LaDonna
A multi-prong solution
You are correct--here in the northwest, mildew is a problem. After a number of years, I found the solution for our boat, a Hunter 380. We use 2 110 V AC Turbo Dryer Dehumidifiers which we got from West Marine. However, I have seen them in other catalogs and a bit cheaper. One forward and one aft, they run all the time. With the Dorades open, they move a lot of air--you can feel it. I also have a heavy duty heater hooked to a greenhouse thermostat. If the tempreture goes below 32 degrees, this sucker cuts in. If it gets below 30 degrees (if the power goes off), my diesel furnace takes over. While the following doesn't have as much to do with mildew, my wife and I agree with LaDonna about putting something under the bunks. We have used DryBunk for several years, but you have to dry the material out from time to time. In Sidney BC, we found a material that looks like a heavy duty one side of velcrow that you can cut and place under your bunk. I've talked to several people who live on their boats and they say it is the best stuff to eliminate moister under the bunk if you have standard matresses. I've added a web site that describes it. I haven't seen it around Puget Sound, just BC. Good luck with the mildew--may you keep it at bay.
You are correct--here in the northwest, mildew is a problem. After a number of years, I found the solution for our boat, a Hunter 380. We use 2 110 V AC Turbo Dryer Dehumidifiers which we got from West Marine. However, I have seen them in other catalogs and a bit cheaper. One forward and one aft, they run all the time. With the Dorades open, they move a lot of air--you can feel it. I also have a heavy duty heater hooked to a greenhouse thermostat. If the tempreture goes below 32 degrees, this sucker cuts in. If it gets below 30 degrees (if the power goes off), my diesel furnace takes over. While the following doesn't have as much to do with mildew, my wife and I agree with LaDonna about putting something under the bunks. We have used DryBunk for several years, but you have to dry the material out from time to time. In Sidney BC, we found a material that looks like a heavy duty one side of velcrow that you can cut and place under your bunk. I've talked to several people who live on their boats and they say it is the best stuff to eliminate moister under the bunk if you have standard matresses. I've added a web site that describes it. I haven't seen it around Puget Sound, just BC. Good luck with the mildew--may you keep it at bay.
Depends.
I have used Rich's colander/bucket method with great results. I use a lot more calcium chloride than he does however. And wiping down all the bulkheads and sole with lemon oil or wax is extra protection. And makes the boat smell great. But I use this method because my boat is covered and sometimes goes uninspected for as many as six weeks. Even if I lived close to the boat I don't know if I could leave anything electrical running. Maybe a couple of light bulbs? Naahh.
I have used Rich's colander/bucket method with great results. I use a lot more calcium chloride than he does however. And wiping down all the bulkheads and sole with lemon oil or wax is extra protection. And makes the boat smell great. But I use this method because my boat is covered and sometimes goes uninspected for as many as six weeks. Even if I lived close to the boat I don't know if I could leave anything electrical running. Maybe a couple of light bulbs? Naahh.
Turbo Dryer & Golden Rods
I'm with Les. The Turbo Dryers (round ones with fan) are really great. We also have a couple of 110vac clip on fans that we leave on while we are away. These keep the air circulating. Our marina does not allow 110vac light bulbs or space heaters when we are not aboard. For closed areas like under settees or in closets Golden Rods are also a good choice.
I'm with Les. The Turbo Dryers (round ones with fan) are really great. We also have a couple of 110vac clip on fans that we leave on while we are away. These keep the air circulating. Our marina does not allow 110vac light bulbs or space heaters when we are not aboard. For closed areas like under settees or in closets Golden Rods are also a good choice.
dampness
Dave, we get damp winters in the north west don't we. I use a passive heater that you can see advertised in west marine. looks like a silver 12" hockey puck with 1/4 inch holes in it, I also use a small electric fan in the vberth to circulate air. These two have very low hydro draw. The important thing is to have the interior temperature higher than outside otherwise you create condensation on the inside of the hull and ports. I also use a nicro solar/nicad exhaust fan which works great to draw out damp air and create circulation inside and a calcium cloride container. Closing up your boat tight would be a big "green" (mouldy) mistake.
Dave, we get damp winters in the north west don't we. I use a passive heater that you can see advertised in west marine. looks like a silver 12" hockey puck with 1/4 inch holes in it, I also use a small electric fan in the vberth to circulate air. These two have very low hydro draw. The important thing is to have the interior temperature higher than outside otherwise you create condensation on the inside of the hull and ports. I also use a nicro solar/nicad exhaust fan which works great to draw out damp air and create circulation inside and a calcium cloride container. Closing up your boat tight would be a big "green" (mouldy) mistake.
HEPA Filter Anyone?
Has anyone thought about puting on a HEPA filter? That's in addition to the Goldenrods, Dryers, and any fans.
Has anyone thought about puting on a HEPA filter? That's in addition to the Goldenrods, Dryers, and any fans.
Open hatches
Scott, Watch out for open hatches. Several boats around me, when in the Everett Marina, left hatches open over the winter. They ended up having rats move in. I'm now in the Anacortes Marina, and have heard of similar situations there. Rats love Marinas, so be careful, get a Nicro vent or fix good rat proof screen to any open hatches to keep them from finding a home in your boat.
Scott, Watch out for open hatches. Several boats around me, when in the Everett Marina, left hatches open over the winter. They ended up having rats move in. I'm now in the Anacortes Marina, and have heard of similar situations there. Rats love Marinas, so be careful, get a Nicro vent or fix good rat proof screen to any open hatches to keep them from finding a home in your boat.
Mildew
Under our bunks and mattress we slide one of the styrofoam noodles kids use for swimming. They don't take on moisture and they create just enough space to allow some air movement around things. Works great.
Under our bunks and mattress we slide one of the styrofoam noodles kids use for swimming. They don't take on moisture and they create just enough space to allow some air movement around things. Works great.
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