Propane - Can I Keep It Simple

Jan 11, 2014
12,436
Sabre 362 113 Fair Haven, NY
On my non-pressurized stove it most certainly does not burn clear. I can definitely see the flame. Also, unless you fill the canisters while they are still hot (i.e., operator idiocy) refilling them is hardly a fire hazard. Someone who is that inept ought not to be sailing a boat! :)

I use an empty soup can with a small hole drilled in the bottom to fill the empty, *cold* canisters. I put the canister in the sink, set the soup can on top of the canister, and then pour the alcohol into the soup can. The small hole slows down the flow so that it will not overflow the canister. It's about an easy as can be and perfectly safe.
Put some alcohol on a flat metal surface outdoors, an old baking pan works. Light it. Most of the flame will be clear or very light blue and difficult to see. Where you do see yellow it is the product of incomplete combustion or contamination in the fuel or burner.

If you fill a canister in the sink you're much safer, filling a canister in the stove can allow some alcohol to spill and puddle in the stove or if you are sloppy it end up elsewhere where it will be easy to ignite. Best practice is to fill a cold canister outside in the cockpit.
 
Nov 22, 2011
1,243
Ericson 26-2 San Pedro, CA
Put some alcohol on a flat metal surface outdoors, an old baking pan works. Light it. Most of the flame will be clear or very light blue and difficult to see. Where you do see yellow it is the product of incomplete combustion or contamination in the fuel or burner.

If you fill a canister in the sink you're much safer, filling a canister in the stove can allow some alcohol to spill and puddle in the stove or if you are sloppy it end up elsewhere where it will be easy to ignite. Best practice is to fill a cold canister outside in the cockpit.
I won't dispute the test you have suggested one way or the other. But this test is of no particular interest to me, at least. When I burn the alcohol on my Origo stove the flame on the burners presents a quite visible blue color. I *never* have had to wonder whether or not the stove is lit. That is the only situation of practical concern to me because it is the only context in which I would be lighting alcohol on fire on my boat.

Filling the canister in the stove is expressly prohibited in the instructions that come with the stove--for obvious reasons. But to state the obvious, unless the stove were completely cold, it would be dangerous to do so. Even if it were cold, I agree that the potential to spill alcohol inside the stove would be reason enough not to do it. So, just read the directions, use common sense, and don't fill the canisters inside the stove! Besides: quite apart from the safety issues, it would be awkward to do in the first place; anyone who has actually used one of these stoves will know why that is so.

I see zero reason to fill the canisters in the cockpit--unless, maybe, you are trying to fill a canister with the boat pitching in a gale? Otherwise, putting a *cold* canister in the sink and filling it as I have described is entirely safe.
 
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Likes: DJAY
Jan 19, 2010
12,548
Hobie 16 & Rhodes 22 Skeeter Charleston
This is not accurate. The molecular weight of Oxygen is ~16 g/mol and in its usual form as 02 the weight is double or 32 g/mol. The dominant gas in the atomsphere is nitrogen which has a molecular weight of ~7. Ethanol aka denatured alcohol has a weight of ~46 g/mol. It is quite heavy.

Alcohol burns with a clear flame making it difficult to see. The big issue with pressurized alcohol stoves was a leak which would then ignite and not be seen until it was too late. Filling non-pressurized canisters in the cabin also presents a fire hazard if it spilled for the same reason.
Apologies in advance... I can't help but put on my professor hat. First, the atomic number of Nitrogen is 7 which is how many protons it has ... the molar mass is 14 g/mol (Nitrogen also has neutrons) and the natural state of nitrogen is also diatomic (N2) so the nitrogen molecule has a molar mass of 28 g/mol.

Also, this thread is about safety and the settling in the bilge thing is certainly a factor but...ethanol is much safer than petroleum fuels because the FLASH POINT of ethanol is +55F and for propane it is -155F. So any little spark will set of a propane vapor.

Also, the density of gasses is not purely a function of mass. The density is a function of the inter molecular forces of attraction. Some molecules are polar (like small magnets) and the positive and negative ends attract and make them more dense in the gas phase. You are correct that non-polar molecular density is proportional to mass and neither N2 or O2 are polar so they are relatively less dense than some other gasses but for non-polar molecules the inter molecular force of attraction is very small and the molecules have to be very large before there is any appreciable force of attraction. All molecules that have a hydrogen directly bound to an oxygen have something called "hydrogen bonding" which is a VERY strong polar interaction. Ethanol can hydrogen bond and the inter molecular force of attraction is high. That is why it is appreciably more dense than air. For example, the inter molecular forces of attraction are proportional to boiling point. The b.p. of oxygen is ~-183C, liquid nitrogen is ~-196 and liquid ethanol is +78C. This example is a bit misleading because it also appears as if the boiling points track molecular weight... but lets throw water into the mix. Water has TWO hydrogens bound to each oxygen atom and can therefor hydrogen bond twice. It is extremely polar. Water's molecular weight is only 18 g/mol yet it boils at +100C.

Okay... done venting...:biggrin::thumbup:
 
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Likes: AaronD
Jan 7, 2011
5,323
Oday 322 East Chicago, IN
If you fill a canister in the sink you're much safer, filling a canister in the stove can allow some alcohol to spill and puddle in the stove or if you are sloppy it end up elsewhere where it will be easy to ignite. Best practice is to fill a cold canister outside in the cockpit.
When I had a non-pressurized Origo alcohol stove, I put the fuel in a squeeze bottle with a built in spout....sort of like this...
38C20A5D-860F-498A-B0F5-FCF38EB9F37D.jpeg
it made filling the canisters much easier...I still took them outside in the cockpit to fill them, but it was so much easier than trying to pour the alcohol from an open top can.

Greg
 
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Likes: rgranger
Mar 26, 2011
3,634
Corsair F-24 MK I Deale, MD
Most denatured ethanol is 50% methanol/50% ethanol. Methanol has a MW of 32, which is insignificantly different from air. Gasoline, on the otherhand, has about 3.5 times the vapor density of air. Just sayin.'

The canister is leakproof. The stove body is leakproof as a back up. Only a moron would fill the reservoir with it still in the stove (there are warning labels) (if you have done so, well....). Same for refilling a hot stove. I've never heard of an Origo causing an explosion, only countertop fires resulting from sloppy filling. This smells like a red herring to me.

---

I learned on Siva pressurized white gas backpacking stoves. I've got one on the bookshelf. Anything else seems safer!
 
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Likes: Alan Gomes
Jan 11, 2014
12,436
Sabre 362 113 Fair Haven, NY
I learned on Siva pressurized white gas backpacking stoves. I've got one on the bookshelf. Anything else seems safer!
And we would lie in our tents with stove just under the tent fly when it was raining. Sometimes it is a wonder we lived long enough to sail. ;)
 
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Jan 19, 2010
12,548
Hobie 16 & Rhodes 22 Skeeter Charleston
And we would lie in our tents with stove just under the tent fly when it was raining. Sometimes it is a wonder we lived long enough to sail. ;)
right...pressurized coleman stoves... bikes with no helmets... cars with no seatbelts.... riding in the back of Uncles pickup shooting street signs with our slingshots.... summer in the bayou shooting snakes with a 4-10 and still here to talk about it.
 
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Mr Fox

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Aug 31, 2017
204
Marshall 22 Portland, ME
If you want simple, nothing beats the origo. I love my 3000. I personally like the least amount of explosives on my boat as possible. I was able to source a basically new one from minnie’s chandlery (I think in CA?) for $120. I keep that one for spares as the 40 year old one I have works perfectly with the only maintenance it has ever needed being a spritz of grease on the sliders, once. Talk about easy.

People ditch these things in favor of propane, so you can find them used. I get it, once you have a professionally installed set up I’m sure that large propane tank and push button convenience is great.

As others have said, the alcohol flame is visible in a burner, it will burn very light elsewhere. The simple step of not filling the tanks over the stove as per the instructions makes it completely safe once it’s closed back up. The difference in cooking time for me is meaningless (a couple minutes more to boil water, oh the horror! And I have kids...)

Anyhow for simple, non pressurized alcohol cannot be beat. A professionally installed propane system is a great convenience. Either drop in an alcohol stove yourself or have a full propane system installed so you can sleep soundly, and enjoy the sailing!
 
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Likes: Alan Gomes
Sep 17, 2018
95
Hunter 23.5 Charleston, SC
It sounds like the dangers of propane in the cabin have been expressed enough.

I've been going thru a lot of propane in the little 1# bottles. I store them outside in a fancy Magma tote bag:
401601LBSJET.jpg

These little brass caps are great for keeping the 1# propane bottles from leaking in between uses.
61QqM1ce59L._AC_SL1024_.jpg

-Z
 
Mar 26, 2011
3,634
Corsair F-24 MK I Deale, MD
It sounds like the dangers of propane in the cabin have been expressed enough.

I've been going thru a lot of propane in the little 1# bottles. I store them outside in a fancy Magma tote bag:
View attachment 177605

These little brass caps are great for keeping the 1# propane bottles from leaking in between uses.
View attachment 177604

-Z
^^^ This is a useful post. Thanks!