Clay Pot Heater?

[Marauder]

Was told of a way to heat the boat during winter but I'm not sure if it actually works or is it safe. They say to heat a non glazed clay flower pot on the gas oven hob which supposedly will continue to heat the boat for some time. Has anybody ever heard of or used this method? With winter nearly upon us I want to keep the wife happy and to keep cruising and not spoil my lifestyle.

[GordMay]

A stove or oven is not a space heater, and shouldn’t be used in this manner.

The clay pot, used on a stove-top, is more of a diffuser than a heat-sink. It’s a bad idea.

[seafox]

Just drink more rum

[Pblais]

I've heard the flower pot method. A lot of bad ideas hang around longer than they should. In the end a flower pot won't stay hot very long. 15 minutes is about all I would expect. Burning propane or other fuel on the stove just raises the humidity far too high, and depletes the oxygen. There could also be a danger for carbon monoxide too.

Drinking too much rum might be safer, you won't be any warmer but you'll think you are. With the flower pots you'll still need a drink and not be any warmer.

If you are going to burn anything inside the cabin it needs to be vented outside to get rid of the moisture. Burning makes CO2 and water when it's efficient.

[Alan Wheeler]

And the flowers don't tend to like it much either ;-)

An effective "radiant" heater is all about surface area. It needs to be in contact with as much air as possible and the air needs to be able to move past the hot surface. A pot would have little surface area in reality. The next problem witha clay pot is the ability to store heat energy and then release it in a controlled manner. I doubt it could store much heat energy, but being clay, I see where the idea may have come from in releasing the heat in a controlled way.
I would suggest you look for a more efficient5 heating source and one that will evacuate exhaust gasses outside than having them remain inside.

[Starbuck]

I've heard of this low-tech approach, too. I seem to want to connect it to Bernard Montessier for some reason.

Rather than blast the pot, then let it coast, the approach is a very low, continuous flame that heats the pot, which in turn acts as a ceramic heating element to radiate the heat about the saloon.

Possible, but there are certainly better ways. Maybe this can be a start to your research: Marine Stoves and Heaters. There is an interesting link on this page to a variation on the ceramic flower pot element that uses a candle: how many cubic feet it can actually heat is uncertain.
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BTW, alcohol in the bloodstream acts as a vaso-dialator: it relaxes constricted blood vessels and allows warm blood from the body's core to travel to the skin and extremeties, causing the sensation of warmth (that's why your face feels flushed after a couple). But the overall effect is a loss of core heat, so you wind up colder than before if you're not burning calories. Not the best "alcholol heater."

[hellosailor]

The flowerpot is a good way to make a cooktop burner into a better heater--but that doesn't mean it is a good way to make a heater in general.

[Hubec]

A gas burner will output a constant amount of BTUs regardless of what's placed above it (if anything). If it isn't heating the pot it will just be heating the air. Either way the exact same amount of heat energy is added to your cabin. The only advantage the pot has is that it will continue emiting a relatively small amount of radiant heat for a short period after you turn the burner off. The obvious reasons not to use this method are; adding CO2, consuming Oxygene, and adding water to the cabin air.

[svHyLyte]

On our old boat--a Cal 2-29 that we had for many, many years, we had a CNG Gas Range that, with a clay pot otherwised used for cooking chicken, we'd keep the boat warm over night, commonly on trips to Catalina. Typically, we'd soak the pot in the galley sink for several hours. We'd then line it with aluminum foil and dump in a pot of of stew or chillie when we were about half-way to Catalina and fire up the range. Once we arrived--say 2 hours later and usually at 10:00 or 11:00 pm, we'd have a nice hot dinner ready once we picked up our mooring and, having eaten we would leave the pot--foil liner and dinner removed--in the oven, with the door ajar, and it would continue to radiate heat most of the night. Many early Saturday mornings I awoke to a warm cabin when it was frosty outside. It was a sizable pot, well soaked and heated, and we avoided having the gas or a burner on whilest we slept. Cheers, s/v HyLyte!

[mudnut]

I am amazed that the Kiwi's on the forum have not let thier secret be known,If only to boost Newzealands export $$$$.POSSUM SOCKS!!!. They are the most heat generating article of clothing that I have ever worn.Cudos to Jo's Mum who occationly sends or brings a pair over every year.Thin as toilet paper and warm as hell.Seriously though.Rugg up with sensible attire and when in bed a good wool blend doona.And in the morning when ya get up,put ya Possum socks on first thing.Mudnut.

[Alan Wheeler]

Possum skins! ain't they amasing. And to think they are an out of control pest here in NZ we desperatly want to get rid of. Along with the Rabbit.
Hey Mudnut, are the Possum or O'Possum protected over your way. I can never remember who has which one. O'possum or Possum.

[seafox]

Hey Wheels, Mite come over in the morning.

[mudnut]

Originally Posted by Alan Wheeler

Possum skins! ain't they amasing. And to think they are an out of control pest here in NZ we desperatly want to get rid of. Along with the Rabbit.
Hey Mudnut, are the Possum or O'Possum protected over your way. I can never remember who has which one. O'possum or Possum.

Hey Alan,the possom is a local over here.The problem over your way was caused by some Kiwi bloke letting them go in the wild after his buissnes idear went wrong<GR>.I take it you don't know about possum socks.Once apon a time you could make a living shooting P's from the state government in Tassie,But I'm not sure about now.Personly,I don't like killing animals(Unless ya can eat them )Ya better watch out for the Hemi's.Mudnut.

[seafox]

On boat now Alan. Leaving at 6am in morning. Lots of time to catch up this time.

[Boracay]

Possums are protected in Australia.

O'Possums are protected in Ireland.