Condensation

[Lepke]

Originally Posted by john61ct

Active ventilation is the key, even when temps don't require it

When it gets cold, people try to block any air exchange. All the moisture from cooking, showers, and breathing (people expel moisture in their breath) stays in the hull if it's not vented. A vented hood over the stove helps as does a powered head vent. But a diesel stove/heater is one of the best ways. If all else fails, a dehumidifier.
The condensation over the v-birth is from you. Especially is the boat air is already carrying a lot of moisture.

[wrwakefield]

Welcome to cool weather boating...

Short answer: ventilate, and fire up that heater even if it isn't 'cold enough' yet... just vent the excess heat... If you don't all that moisture is also accumulating behind headliners, ceilings, etc. and will support all kinds of growth you would likely prefer to avoid...

Longer answers:

Bone up on Psychrometric Charts re: Temp-Dew Point spread.

If you are really a glutton for punishment, read our blog posts on this topic. It is something we are asked about often...

Wishing you a warm [and dry...] cool season...

Cheers! Bill

[john61ct]

Originally Posted by Lepke

When it gets cold, people try to block any air exchange. All the moisture from cooking, showers, and breathing (people expel moisture in their breath) stays in the hull if it's not vented.
…
The condensation over the v-birth is from you. Especially is the boat air is already carrying a lot of moisture.

Yes, exactly my point.

Trying to stay warm that way is foolish. Yes the living space should not have random uncontrolled infiltration / convection heat losses, part of proper insulated is a tight envelope.

But that makes well-controlled high-CFM ventilation all the more necessary.

Active heating sources are required at extreme temps, and of course should not add humidity but with proper combustion venting reduce it.

But for those willing to rough it, proper clothing bedding etc can go a long way in moderate climate.

You just can't eliminate air exchange with the outdoors.

[Gregjo]

Anyone tried Mascoat marine insulating paint?
The specification looks promising.....

[john61ct]

No coating that thin will ever have that significant insulation R-value

[rbk]

Insulating paint lol. Every time I hear those words in combination I think of the below story.

https://www.greenbuildingadvisor.com...is-own-product

[Gregjo]

Originally Posted by john61ct

No coating that thin will ever have that significant insulation R-value

Yep, that’s what I thought!

[SSgtPitt]

Originally Posted by rbk

Insulating paint lol. Every time I hear those words in combination I think of the below story.

https://www.greenbuildingadvisor.com...is-own-product

The idiocy is astounding. Where is Natural Selection when you need it most?

[SV_Harbinger]

I am consistently amazed by the number of people who are taken in by all the ad hype on some of these miracle products, it literally blows my mind. Goes to prove the statement that, "no one ever went broke under estimating the intelligence of the general public".....

[DeepFrz]

Originally Posted by owly

In a slip, a fan is pretty much a necessity, on a mooring or at anchor, there really is no reason why a venturi system cannot adequately ventilate a boat. Obviously a catalytic heater adds moisture to the air, while a stove with a chimney removes it.... at least obviously to me. I've run catalytic heaters for just that reason in extremely dry climates. The abrupt temp change by a cold surface results in a lowering of the dewpoint of the air at the contact point which causes condensation... the reason windows frost or steam up. A foam sandwich or wooden boat is going to be far less of a problem than a solid GRP or metal boat...... Aluminum is by far the worst choice. (for other reasons also)



H.W.

Except that all well built aluminum boats are very well insulated and so are better suited for weather extremes, hot or cold. It also makes them quieter boats.

[Endeavour35.5]

Don’t forget to check under your sleeping cushions.
I insulated under my mattress with 1” foil backed foam (R-Max).
Available at any home repair store.
After cutting I seal the edges with a high quality duck tape. 3M
Stops condensation from entering your mat from underneath

[Endeavour35.5]

Also you can use the extra R-Max to make a plug for the hatch, keeps out cold and light.

I would post pictures but I don’t know how to reduce the size on my iPad.

Is there a link here on how to do that?

I also have some cool pics of a chain plate / bulkhead failure and repair from 30 plus knots of wind.

[john61ct]

Originally Posted by Endeavour35.5

I would post pictures but I don’t know how to reduce the size on my iPad.

I post to imgur then link.

There are image editing apps too.