blame the fabric hatchboard/companionway cover

[centerline]

the past two months since I bought the boat, ive been dealing with moisture in it.
the hull sweats profusely... so bad that I thought the hull was bleeding thru, as you can see the exact waterline in the condensate.... although the bilge water never rises... its just condensate.

we have spent every weekend on it doing the usual "new-to-us" boat repairs and tinkering, and it always felt damp for the first 30 minutes when opening it up after its sat all week sealed up. It came with a sunbrella hatch board cover, the kind that everyone seems to want for their boat, and we have kept that over it, even though we have a dodger.
we have also kept the electric heaters going to keep it warm so it would dry out, but this has not helped.

I wanted to keep as much heat in as possible so I kept the cover in place when we were away, and even though we have kept it warm inside, I have realized there was no where for the moisture to evaporate to... other than condensate on the hull and start its process all over again.
and there is NO passive or active ventilation in the cabintop, cockpit or hull.

so in an attempt to let some of the heated, moisture laden air escape, I have left the fabric hatch cover off but still kept the hatchboards in place and locked... and in two weeks my hull is now dry and not sweating any more. still have the heaters running.

just the smallest bit of gap that is between the slider and top board,1/4" to 3/8" of an inch is enough to allow the condensate to evaporate....

So, I will be installing a solar vent for even better ventilation for the interior, and for anyone who is wishing for a fabric hatchboard cover, they can cause more problems that they are worth if the companionway is your only source of ventilation.....

 

[Pat]

Many years ago we purchased a dehumidifier from West Marine....it sets on the floor or counter and keeps the interior boat temperature above the dew point thereby eliminating
high humidity, condensation, and mildew below. It makes very little noise and seems to have been very effective in keeping the interior dry, minus any hatch leaks, etc....it is about 1 ft. in diameter and I know they still sell them. Our boat has carpet on the bulk-heads and it has virtually eliminated any mildew or dampness below...it is also a safe piece of electrical equipment according to the manufacturer and WM....Pat

 

[Ward H]

CL,
Thanks for posting your experience. Confirms my thoughts that I need to install a solar vent.

 

[Steve Dion]

I would consider a dehumidifier if I had this type of issue. We use one most of the winter aboard our HV'36. We purchased a Sunpentown but many of the other ones are as good or better.

You may think about purchasing a 70 pint model. They are around $250+ but it will help with the moisture. We have ours sitting on the counter in the galley with a drain in the galley sink.

I doubt that the solar vent is going to take care of your problem.

 

[Joidevivre]

I love my EvaDry dessicant dehumidifier. I leave it running in the wet months. I stand it in our icebox w a drain hose. Boat is dry and clean smelling and don't have to run a space heater which always make me nervous. I had a near meltdown once when the extension cord plug started melting. Thank god I caught it in time. The dehumidifier uses way less power, and blows out slightly warm air. It's good to just about 0deg, too, since its dessicant, not compressor tech.

http://evadry.mobi/products/edv-4000-rotary-desiccant-dehumidifier/

 

[Skipper]

I put the WM air dryer amidships, plus 3x DampRid tubs; 1 in the V-berth, one in an open salon cabinet, and one in the quarter berth. Boat is always dry. Tubs need replacing every 3 or 4 weeks in the warm months, but they're cheap, and a tiny price of inconvenience for desired results.

 

[Anonymous 121765]

Center,

The guys are correct. You need to vent your boat. Closing it off will allow moisture to build up mildew. Also, temp & humidity changes complete the equation.

Here on Florida's left coast, spring & fall yield a lot of this. unless you run A/C/ humidifier year round, It will never be perfect but better then you have now.
I use a Waste Marine air dryer, but there's a lot of products to chose from.

I'm in salt water & saltwater never really dries. It always leaves a salt film. I also have a PSS waterless shaft seal. I don't have water in my bilge most times. A lot of humidity comes from your bilge.

My hatch & companionway slates are NOT totally waterproof either. Rain water will get in at times. All of the above come into play for moisture inside your boat.

I forget to mention any water from thru-deck fittings & portals.

CR

 

[centerline]

I read all the posting about dehumidifiers.....

some one needs to explain to me how they work. because I have seen the ones in the marine supply magazines and they look to be only a small, low amp heater with a fan....
this will help "dry" a small area as it will suspend the moisture in the air, to be moved out with the normal air flow thru the boat.... BUT, this it ONLY providing there is air flow into and out of the cabin space from the outside. without ventilation, there is no such thing as dehumidifying...

A proper Dehumidifier that has a drain, that will condensate the moisture from the air that moves thru it, and then dump that moisture overboard acts similar to a A/C unit, and would be the most effective in every case, but a small heater/fan dehumidifier, as seen in the magazine is only a heater/fan unit that does NOT dehumidify, but only suspends the moisture in the air to settle out elsewhere, UNLESS it can escape from the interior...

my original post was about a fairly well sealed ENCLOSED space... I have no trouble suspending the moisture, but there was so much and it couldnt get out to be displaced with drier air, so it was only a cycle of condensate-to-water-to-evaporation-to condensate... and around it goes!

it was a post about the use of a hatchboard cover without any other means of ventilation into or out of the boat...

the bilge in my boat is a narrow deep sump bilge... not too much escapes from there in the form of evaporation in these cold waters...

 

[Skipper]

I have a hatch cover. Boat is sealed tight. Only air in\out would be through the vent holes in the center hatch board, which are covered by the canvas.

Boat is dry, in all conditions. The air dryer reduces the chance of condensation of moisture that may be present, while the DampRid tubs dehumidify. That is, they remove the water from the air, and store it in their tubs till I empty them.

I too question the labeling of the WM unit as a "dryer" or "dehumidifier". That's what they call it. It might be more appropriate to call it an "anti-condensation" unit.

Anyway, the combo of gear mentioned above works for me, with the hatch cover in place.

 

[Skipper]

Boat is sealed tight. Only air in\out would be through the vent holes in the center hatch board, which are covered by the canvas.

Sorry, not exactly true. The engine room is ventilated through deck cowls in the cockpit, and the air does make it into the cabin through the galley access door. Not sure if this helps in the equation. The only reason I seal the cabin is that it doesn't seem to matter when using moisture defense, and I don't want water intrusion caused by an open port. However, any waterproof ventilation for a boat is argued in favor. It certainly can't hurt.

 

[Chris Patterson]

For what it's worth, I had the exact same problem, and no amount of ventilation helped, fans, whatever. I threw 250 dollars at the problem, and now when I open up the boat, it's so dry in there your eyes won't blink..

(That's about a sorry ass picture, but it's supposed to be a Soleus dehumidifier).

 

[Skipper]

it's so dry in there your eyes won't blink.

It's so dry, I can get SSB reception through my hair.

 

[Nom De Guerre]

For what it's worth, I had the exact same problem, and no amount of ventilation helped, fans, whatever. I threw 250 dollars at the problem, and now when I open up the boat, it's so dry in there your eyes won't blink..

(That's about a sorry ass picture, but it's supposed to be a Soleus dehumidifier).

Not to be a Debbie downer, but the first two links when I began researching a Soleus dehumidifier were regarding recalls and fire incidents.

Probably unrelated to your model, but in the interest of 'better safe than sorry'...

http://www.cpsc.gov/en/Recalls/2013/Gree-Recalls-12-Brands-of-Dehumidifiers/

 

[firehoser75]

I use a dehumidifier

Thanks for the recall info. Definitely something you want to stay on top of. There is a good book on this subject by Roger McAfee, I think it is called the "Warm, Dry Boat".
Anyway, you need adequate ventilation with good air movement, or you can "close up" the boat and use a proper dehumidifier. I have successfully used a Whirlpool brand dehumidifier (with the drain hose draining into the galley sink) for about 5 years now. I live in the lower mainland (Vancouver) of B.C. and now nearby in Nanaimo where it is very humid, especially in the winter (very similar to Salem). My boat is very dry inside, (all cabins (3) with only one dehumidifier) with no strange smells. By the way, if you use those dehumidifier tubs that use the white granular powders to collect moisture, you need to empty them regularly or the collected water will start to evaporate back into your boat's "atmosphere" somewhat starting a cycle.
Anyway, good luck with your issue,

 

[Chris Patterson]

Yeah Nom, I appreciate that. I had already seen it, and absolutely about flipped out when I did. My particular model wasn't included, but I'm glad you posted the link,(I forgot about it), so no one here gets caught in that trap.
Damprid was good, but it was steady losing. I now commonly see ranges in the teens and lower twenties when the humidity outside is very high.
I have often wondered if there is such a thing as TOO dry. So far, not in my boat..

 

[Maine Sail]

There is only one good effective way to deal with interior moisture.. A DRY BILGE! Get your bilge dry and these issues will be in the past..