Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 16-10-2009, 05:05   #16
Registered User
 
Spammy's Avatar

Join Date: Mar 2008
Boat: Catalina 42: Quetzalcoatl
Posts: 114
ventilation:yes. But that is not sufficient. If the temperature of the hull falls below the dew point for the relative humidity of the air inside, condensation will happen, whether there is air movement or not. Inslation will help by keeping the temperature of the inside surface of the hull closer to that of the air inside, and of course, dehumidification of the air inside the boat works. For us, in sunny South Florida, an air conditioner is the answer, but of course it is an energy hog, and not a great solution for when you are on the hook, unless you have a genset and enjoy the noise and diesel fumes of the exhaust...
__________________

__________________
Spammy is offline   Reply With Quote
Old 16-10-2009, 06:54   #17
Writing Full-Time Since 2014
 
thinwater's Avatar

Join Date: Nov 2008
Location: Deale, MD
Boat: PDQ Altair, 32/34
Posts: 4,339
Beware of condesation behind the insulation, against the hull.

A great formula for mold.

Although insulation will prevent condensation where you can see it, if the humidity is above the dew point at the coldest surface of the hull the air will find, there will be condensation. This is avoided in homes by using a vapor barrier on the inside and having insulation that breaths to the outside; but hulls do not breath.

So, unless your hull is cored everywhere - unusual to say the last - you will need to dry the boat below the dew point. That depens on the climate, it will be perhaps 10-20F above the outside temperature (since the inside of the FRP will be ~ 1/2 way in between inside and outside temps).

Insulation is fine; just make sure there is ventilation between the layers and that the boat remains low in humidty too. Otherwise it will be like the pesky condensation beteen storm windows that just won't go away.
__________________

__________________
Gear Testing--Engineering--Sailing

Writing full-time since 2014.
Bookstore:http://sail-delmarva.blogspot.com/20...ook-store.html
thinwater is offline   Reply With Quote
Old 16-10-2009, 07:47   #18
Registered User
 
avril25's Avatar

Join Date: Jul 2009
Location: I live in Soutbridge, MA and Sail out of New Bedford
Boat: 82 O'day 25, Shadubie
Posts: 23
Images: 2
So fare I've got good ventilation. A solar powered vent fan, worked great all summer
I was thinking of adding another. I like the idea of a small wood stove, where can you find those, any recommendations. I currently have a Kenyon alcohol stove. Have not used it in the winter yet. Today is the coldest day so far. I'm going down to the boat to check it out and see it like inside with the heat on.
__________________
avril25 is offline   Reply With Quote
Old 16-10-2009, 08:53   #19
Registered User

Join Date: Jul 2008
Location: Vancouver Island
Boat: 27ft catalina
Posts: 492
dickenson makes a nice small solid fuel heater its a small unit designed to work with bbq briquettes coal or small pieces of wood. i have no experience with it but from talking with dickenson it seems to be quite popular.
__________________
michaelmrc is offline   Reply With Quote
Old 17-10-2009, 00:02   #20
Registered User
 
rustypirate's Avatar

Join Date: Nov 2008
Location: Largo, Florida
Boat: Bruce Roberts Offshore 38
Posts: 268
Images: 10
Back when my family were cruising we encountered this same problem. We were able to recitfy it simply by putting a layer of styrofoam sheet against the hull wherever accessable, and this practically eliminated the problem.

Now, many years later, I would not recomend styrofoam to ANYONE considering it's toxic fumes if ignited.

There are several manufactures of spray-on foam kits that are closed-cell, and have an E84 flame retardent rating. You can also paint them with flame retardent latex paint available at most paint retailers to gain yet another level of flame retardence. The spray foam eliminates the possibility of condensation building up between the foam and the hell/deck as it bonds to the material it is sprayed onto if properly prepped.

The real downside to spray foam is that it is hell to get off if you need to work on the area that is covered.
__________________
rustypirate is offline   Reply With Quote
Old 17-10-2009, 17:01   #21
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,772
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
keep more ports open ...ventilation--i have no problem whatsoever with condensation--havent since i learned to keep all my hatches and ports open year round--even in winter when it is 38 degrees---i keep the ports open with the heating system turned on ...and wear lots of clothing for warmth and feather quilts.....and more ventilation.....

Quote:
Originally Posted by michaelmrc View Post
dickenson makes a nice small solid fuel heater its a small unit designed to work with bbq briquettes coal or small pieces of wood. i have no experience with it but from talking with dickenson it seems to be quite popular.
best ventilate with this or will find you deader than fred.....
zeehag is online now   Reply With Quote
Old 20-10-2009, 14:03   #22
Registered User

Join Date: Oct 2009
Location: Aboard - wherever we may be
Boat: OVNI 435 - Pelerin
Posts: 39
We also have an aluminium hull, but instead of sprayed on foam we have 5cm of board type insulation for the deck and the hull down to the waterline. This has been cut to shape to fit snugly between the frames and stringers of the hull that are themselves covered with glued neoprene strips around 10cm wide, which also help to hold the insulation in place. Last December we had temperatures down to -6 C and had no major problems with condensation beyond the aluminium hatch frames (a problem we hope we're working on for this winter). We use just a small fan heater and occasionally our Webasto diesel blown air heater when it's really chilly, and wrap up if we need to, but we're generally very comfortable.

Insulation makes a real difference to an aluminium or steel boat, and the latest techniques seem to work well - without it (and good ventilation!!) a metal boat can be about as welcoming as a crypt in winter. I'm sure that some of the same techniques could be applied retrospectively to a GRP boat and could make a real difference, although it might be a big job to get behind the joinery.
__________________
Sharkman is offline   Reply With Quote
Old 21-10-2009, 19:07   #23
Registered User

Join Date: Oct 2009
Posts: 7
Arrow

Soleus
__________________
SemperParatus is offline   Reply With Quote
Old 22-10-2009, 05:29   #24
Registered User

Join Date: Oct 2009
Location: Maryland
Posts: 3
We lived aboard three winters on the Chesapeake w/o condensation issues. We were insulated from the waterline up, well ventilated, heated with a newport propane stove and showered on shore. Think about condensation on a single pane of glass, it is the same as your 1/4-1/2 inch of fibreglass between you and the outside. We also had dri-dek under the v-berth foam. The newport could burn 24/7 on high for 4 days on 20 pound tank or 7 days on low. Very dry heat with no smell and totally sealed from the inside.
Mike
__________________
illusion_realit is offline   Reply With Quote
Old 22-10-2009, 05:59   #25
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 3,060
Dry...

Dry your bilge and add some ventilation. Having a wet bilge is basically like a small scale indoor pool.

Our bilge is always bone dry, we have solar vents and a dorade, and even in Maine during the early and late seasons we don't get any condensation.

Oh and don't try and heat your vessel with non-sealed combustion LP as it gives off copious amounts of moisture as part of combustion.
__________________
Marine How To Articles
Maine Sail is offline   Reply With Quote
Old 02-11-2009, 15:04   #26
Registered User

Join Date: Mar 2009
Location: Morlaix Brittany France blog: theguerns.blogspot.com
Boat: Colvic Watson/32ft/Feels Good
Posts: 461
Images: 4
Send a message via Skype™ to feelsgood
insulation

Quote:
Originally Posted by avril25 View Post
I was wondering how people who live aboard deal with condensation that develops on the walls and ceilings. in winter or summer. Does insulation help.
what type of insulation works best. I see a DIY spray on high density foam,
1 inch equals 7.7 r factor Has anyone tried this. Do those electric dehumidifiers work. Any suggestions.
I have just insulated a Sadler 32 for a client with 4mm cork he now has NO condensation and the boat is both warmer in the winter and cooler in the summer. if you want to know more give me a call.
Regards Pete
__________________
feelsgood is offline   Reply With Quote
Old 02-11-2009, 17:10   #27
Senior Cruiser
 
rebel heart's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Posts: 6,190
Images: 3
Haven't had any condensation problems myself on my current boat (Hans Christian). Had a bunch on my previous (Ericson). I have a lot of airflow, and use a cabin heater in the winter. Electric at the dock, diesel on the move/hook. Anything that generates dry heat, and enough airflow to move that dry heat around, dries the boat out.

The worst times are when it's raining buckets outside, and there's wet gear and wet footprints in the cabin. Even with the heat and ventilation, there's a lot of water getting turning into vapor.
__________________
rebel heart is offline   Reply With Quote
Old 02-11-2009, 18:44   #28
Registered User

Join Date: Jun 2009
Posts: 38
Here's another dehumidifier to consider:

About DryZone Systems | Dehumidifiers for boats and motor homes

David
__________________
KairosKona is offline   Reply With Quote
Old 03-11-2009, 03:01   #29
Registered User

Join Date: Mar 2009
Location: Morlaix Brittany France blog: theguerns.blogspot.com
Boat: Colvic Watson/32ft/Feels Good
Posts: 461
Images: 4
Send a message via Skype™ to feelsgood
heater

Quote:
Originally Posted by avril25 View Post
So fare I've got good ventilation. A solar powered vent fan, worked great all summer
I was thinking of adding another. I like the idea of a small wood stove, where can you find those, any recommendations. I currently have a Kenyon alcohol stove. Have not used it in the winter yet. Today is the coldest day so far. I'm going down to the boat to check it out and see it like inside with the heat on.
Try one of these.
http://www.marinestove.com/codinfo.htm
__________________
feelsgood is offline   Reply With Quote
Old 03-11-2009, 03:03   #30
Registered User

Join Date: Mar 2009
Location: Morlaix Brittany France blog: theguerns.blogspot.com
Boat: Colvic Watson/32ft/Feels Good
Posts: 461
Images: 4
Send a message via Skype™ to feelsgood
insulation fixing

Quote:
Originally Posted by thinwater View Post
A great formula for mold.

Although insulation will prevent condensation where you can see it, if the humidity is above the dew point at the coldest surface of the hull the air will find, there will be condensation. This is avoided in homes by using a vapor barrier on the inside and having insulation that breaths to the outside; but hulls do not breath.

So, unless your hull is cored everywhere - unusual to say the last - you will need to dry the boat below the dew point. That depens on the climate, it will be perhaps 10-20F above the outside temperature (since the inside of the FRP will be ~ 1/2 way in between inside and outside temps).

Insulation is fine; just make sure there is ventilation between the layers and that the boat remains low in humidty too. Otherwise it will be like the pesky condensation beteen storm windows that just won't go away.
All insulation ina boat should be glued in place.
__________________

__________________
feelsgood is offline   Reply With Quote
Reply

Tags
condensation

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Condensation Outside / Underside of Fridge svDragonfly Plumbing Systems and Fixtures 6 07-03-2010 07:32
Dealing with a marina? beetlejuice30 Liveaboard's Forum 12 02-02-2009 22:14
Avoiding condensation around water tanks pir8ped Construction, Maintenance & Refit 1 20-01-2009 08:53
Stopping condensation from aluminum hatches? Namoian Construction, Maintenance & Refit 12 16-12-2008 11:00
Standard horizon CP1000c condensation problem stephane Marine Electronics 3 28-03-2007 04:16



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 13:26.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.