How do you stop condensation on bare fiberglass?
In short, you have to reduce/remove the moisture in the air and/or control the temperature of the 'condensing' surface; the fiberglass surface. Be thinking 'Glass of Ice Tea'; You pick up a glass of ice tea, your hand gets wet. It gets wet because the moisture in the air surrounding the glass has condensed, rained, sweated, reached dew-point, (all the same 'term') on the surface (actually, on the air-film) of the cold glass. It also is how all mechanical air-conditioners remove moisture from the air. The moisture in the air condenses on the cold coil, and the condensate water drips out of the unit... The Water-Air-Relationships are a 'perfect' science and are explained on the Psychrometric Chart (PCh) developed by Willis H Carrier (yes, that Mr Carrier). One basic item we need to understand is relative-humidity. Relative Humidity = The number of 'grains' of moisture in the air RELATIVE to the temperature of the air. You will change the relative humidity of any volume of air by raising or lowering the temperature of that air. (When you raise the temperature, you LOWER the relative humidity. When you lower the temperature, you RAISE the relative humidity). Using the PCh you can determine exactly what relative-humidity air will condense on a given temperature surface.How do you stop condensation on bare fiberglass?
In short, you have to reduce/remove the moisture in the air and/or control the temperature of the 'condensing' surface; the fiberglass surface. Be thinking 'Glass of Ice Tea'; You pick up a glass of ice tea, your hand gets wet. It gets wet because the moisture in the air surrounding the glass has condensed, rained, sweated, reached dew-point, (all the same 'term') on the surface of the cold glass. It also is how all mechanical air-conditioners remove moisture from the air. The moisture in the air condenses on the cold coil, and the condensate water drips out of the unit... The Water-Air-Relationships are a 'perfect' science and are explained on the Psychrometric Chart (PCh) developed by Willis H Carrier (yes, that Mr Carrier). One basic item we need to understand is relative-humidity. Relative Humidity = The number of 'grains' of moisture in the air RELATIVE to the temperature of the air. You will change the relative humidity of any volume of air by raising or lowering the temperature of that air. (When you raise the temperature, you LOWER the relative humidity. When you lower the temperature, you RAISE the relative humidity). Using the PCh you can determine exactly what relative-humidity air will condense on a given temperature surface.
Top manage moisture issues, you must be able to measure them. If you don't have access to a Sling-Psychrometer, buy a battery-operated one for $10.00 at a home center. Depending on where (the climate) your boat is will determine what steps are needed to control the moisture in the air, and/or the temperature of your fiberglass surface..... In summary, you have to warm/heat the surface and dehumidify the air that come into contact with the surface.
By the way, this all also relates to mild and mildew issues on boats (or anywhere else mold takes place).
Think "The Fire Triangle". For fire to exist, three ingredients must be present; heat, oxygen, fuel. Get rid of ONE of the ingredients, then there is no fire..... With mold/mildew it is not a 'triangle' it is a pentagon. Five ingredients must be present for mold/mildew to exist. Oxygen, Mold Spores, Mold Food (which is anything organic), Temperatures above 40 degrees F and below 120 degrees F, And Moisture/water. Get rid of ONE ingredient and mold cannot exist. The only one of these ingredient that you have any prayer of eliminating is water/moisture!. And that is difficult on a boat.... Anytime there is water present and/or a Relative-Humidity of 70% or higher, it is not that you 'might have mold/mildew, you WILL have mold mildew, because all of the other 4 ingredients are already there..... You have to control the source of the moisture/water..... If any one is still reading all this, I will be shocked! ☺
Hi Brent, you Floridians are very fortunate, because, well because it's warmer there! ☺ It's harder to find a cool/cold surface for condensation to form on in much of mid to south Florida!I keep side windows opened a little and I installed vents that fit into berth windows from Beckson. They keep rain out and allows air flow. In the cockpit, I used an old deck pie plate to install solar fan. When working it pulls air from.bilge, cabin and sides.. works better than I thought it would. My boat sits on a covered lift in Florida and don't know how or when you are having condensation issues.
Hi Brent, I'm on Pungo Creek in mid-eastern North Carolina, some call the 'Inner Banks'. We deal with four distinct seasons here; hot humid summers, short cold winters, and nice springs and falls. The best and worse of all worlds! ☺We love it. Where are you located? A regular fan on timer will work, too. Our boat still collects water in wheelhouse bilge and solar fans helps to dry it out if sunny. Opening hatches or doors helps too
I live on Prince of Wales Island in SE AlaskaHow do you stop condensation on bare fiberglass?
Hi mb4570, Welcome to Classic Parker!.... My guess is you all have some severe/cold weather there on occasion? !! .... I've have on a dozen+ occasions been a 'few' miles south of there, from the Vancouver area to Whistler/Blackcomb.... you are in a beautiful area! Sea to Sky! One of the most beautiful roads I have been on!I live on Prince of Wales Island in SE Alaska
Hi Antidote, as you've witnessed, Damp Rid bags and/or containers collect moisture from the air, as desiccants (unlike dehumidifying by cooling/condensing). But their intended use is for small, enclosed, nearly air-tight closets/storage areas. And these areas are already inside a home where hopefully there is little moisture in the first place, and reducing and/or blocking the moisture source is easier.... Not the same as on a boat that is not heated and cooled like the home is. An area on an unconditioned boat, with the volume of space of the cuddy cabin and/or pilothouse would require a massive number of Damp Rid containers to make any meaningful reduction of the relative humidity of that space; especially so with the windows cracked. This can be proved by monitoring and measuring the relative humidity; I recommend getting one of the small electronic models (like AccuRite; $9.99) from a home-center. You could do your own experimentation that will show that Damp-Rid, (or any other type of desiccant), although collecting some moisture, are not 'powerful' enough to lower the relative humidity of that space, especially so with windows open/cracked. This is so because of 'vapor-pressure'. Vapor/moisture travels from an area of high-concentration (higher-humidity) to an area of low-concentration (lower-humidity). (Think of this as a 'sponging effect'; a dry sponge drawing in water). If we dry a volume of air, without reducing/preventing the source of the moisture, then we are making no progress in lowering the relative humidity. The more you dry it, the more of a 'sponge' it becomes. Trying to reduce relative humidity with windows open can't work unless the air outside is a lower relative humidity than the area you are trying to dry; I too lived in SC for a number of years, and best I remember, the outside air was often very humid! ☺I leave the side windows open about 2" and close the screens. I also hang a Damp Rid bag in the berth and change it out when it fills up.
Hi mb4570, I just now saw your post here. It's a great question, and I hope I can shed some light on a solution, or why there is no great solution. I'm sorry this is so long, but I didn't have time to write a short explanation. (I did not invent that saying!).what is best material for insulating 1988 2520 pilot house ?
You are welcome; I hope I was at least a little help....Thanks for the reply, this the first Parker boat I've every been around so don't know much about it but I like the style, this 1988 2520 Sou'Wester is no frill's just bare fiberglass in the house so I don't need to remove anything to insulate, just trying to avoid trial & error as much as possible. I live on Prince of Wales Island in SE Alaska so not a lot of expertise around regarding Parker boatsI want to keep this boat as nice as possible its very clean and well kept, the previous owners kept this boat in doors and only used it 3 weeks a summer when they came up to fish so its still a very nice boat. Again thanks for the reply and I'm very amazed at the CP forum it is a wealth of information backed by experienced boaters that share their knowledge freely and definitely love their Parker Boats ! Thanks
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