How to stop the sweating

  • January 14, 2013 7:29 PM
    Reply # 1180014 on 1176805

    Wouldn't it be great to be able to seal up our boats like Mike Holmes in Canada does with his homes!  BUT, like everything we choose to do with our boats there is always a compromise.  Dang it!  Blue foam and no leaks, no condensation, warm in the cold, cool in the heat.  Great, but its a mess to use, once in we can't get to our fittings in the bulwarks, and then there's the stuff we can't see or event think about.

    OK, kidding aside, I do wish there was an easier solution for this.  I agree with good ventilation being a solution, but with our boat, Harmony, being in the condensation producing warm/cold of the Northeast, I am not sure there is a workable passive system for increased ventilation other than what the boat was designed with. Well, the composting toilets, Airhead and Nature's Head use computer fans which presumably could be powered by a solar charged battery.  Hmmm, I would llike to think of a better way.

    Like Jay's foil insulation, I have looked at Reflectix insulation (R=1.7) stuffed into the bulwarks in an upside down U.  It does provide a good radiant heat barrier.  Perhaps it can offset the solar heat gain and night time cooling that keeps the condensation going.  It can be installed without messy adhesives by perhaps using a stainless steel or aluminum wire like the wires used to hold the pink insulation up in the floor joists in homes.  It is fairly cheap and is relatively mold resistant.

    I will be running wires through conduit in the bulwarks over the next couple of weeks, and I will give it a try in a couple of areas.



  • January 15, 2013 12:21 AM
    Reply # 1180121 on 1176805
    Wow, it is great to have this kind of community around.  Lots of ideas and experience.  I have been rolling this around in my head.  I have identified some areas that seem to sweat more than others.  I am going to try reflectex in one, the vacuum packed peanuts in another,  I  have been thinking about how to increase circulation and computer fans seem to be a good choice, at least while at dock.  I was even thinking of possibly running 1/2" pex tube with holes every so often through the bulwarks, plumbed into a small exhaust fan while on shore power.  I really want to reduce this problem as much as I can. Time to start pricing and comparing dehumidifiers I guess.  Is sweating as much of a problem in warmer climates?
  • January 15, 2013 10:47 AM
    Reply # 1180525 on 1176805

    Doug and Chris,

    Sorry for my tardy response, work often gets in the way of fun...

    It appears there are several other possible solutions to the insulated bulwarks issue. To answer your question about moisture absorbtion in the fiberglass batts.  No, we have not experienced any issue with wet insulation in our boat. The insulation batts seem to have addressed the temperature change/condinsation issue in our bulwarks.   As someone else mentioned solar vents are also helpful, we had then when we lived aboard. 


  • January 17, 2013 6:01 AM
    Reply # 1181971 on 1176805

    In response to the question about warmer climates (well, mostly warmer, in North Alabama,) when the weather gets colder here I do tend to get some sweating from the exposed fiberglass in the hanging lockers (the ones not stuffed with sail bags) and in the spaces under the caprail. This last week we had a lot of rain coupled with a temperature drop of 30 degrees F, and I had a lot of sweating issues, particularly with regard to my portlights. I'm talking a lot of water, just dripping off the glass and bronze. Has anyone come up with a solution to sweating of the portlights?


  • January 26, 2013 8:13 AM
    Reply # 1190035 on 1176805
    Anonymous member (Administrator)

    While reading  Robert Sutton's blog I noticed that he is using 1 inch Armaflex  foam insultation.  Below in the V berth.

    If you haven't been following Roberts blog - you are missing his blog about his "from a bare hull and deck" to finished W42 - this will be the "newest" W42 when launched.   


  • January 26, 2013 12:23 PM
    Reply # 1190143 on 1176805

    Robert's blog really is fun to follow along with.  I'm often amazed at the stuff he is doing. 
  • January 26, 2013 4:49 PM
    Reply # 1190279 on 1176805
    Deleted user
    Jay, Armaflex is what we used in Worldwind.  It's closed cell so it won't absorb moisture and has worked well for six years. It's what we used to wrap chiller barrels when I was working.

  • January 26, 2013 5:35 PM
    Reply # 1190290 on 1176805
    Deleted user
    Neat following this thread, does this mean I may have the " newest" w32 ...... If I ever get finished...... My hull is insulated ( foam core) but still adding some, concerned about the bulwark , working on the boat in -25c no moisture I guess at this temp the air is to dry.  I really enjoy the forum pages.... Thanks to everyone.    Nick
  • April 29, 2013 5:36 PM
    Reply # 1281572 on 1176805
    Deleted user
    Very late on this subject! 
    Something you might also consider instead of 'pink' though similar (green in colour). I've used a product from Home Depot called 'Roxul' ( ) for ceilings/floor/walls, it's great stuff! doesn't absorb water, fire proof, good insulation properties, and I believe it's also mold resistant.
    Also, on Douglas Tate comment, I'd consider using the plastic mesh (used in rain gutters) instead of ss or metal.
    Last modified: April 30, 2013 4:32 PM | Anonymous member (Administrator)
  • April 30, 2013 4:36 PM
    Reply # 1282504 on 1176805
    Anonymous member (Administrator)

    I think that "Stone wool"  or rock wool is what Rob was writing about.

    Reviews look good.


    Last modified: November 24, 2013 9:21 AM | Anonymous member (Administrator)
Powered by Wild Apricot Membership Software