# Good to the last drop - HOW?



## rrdude (Feb 21, 2008)

How can I use all my Butane to fill the fuel tanks on these locomotives? 


Particularly on the K-28, it seems to take at least two canisters to fill that tank. (More if they are not all fresh.) I start with the most empty canister first, then move up to fresher canisters as the pressure equalizes in the tank and no more gas comes out. I have to end with a fresh canister to fully top off the tank.

This is leaving me with a LOT of partially filled canisters that I can not get the last bit of butane out of. (I can hear it slosh around, so I know there is some left.)

I could use them on my smaller Ruby and Mogul, but I don't run them as much as the bigger engines.








How can I make better use of these canisters? How does everyone else fill these tanks? Is there a way to 'pump' the gas out of the older canisters, or at least build the pressure back up in them so they can overcome the tank pressure?

Thanks!


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## Dwight Ennis (Jan 2, 2008)

Our own Royce of Quisenberry Station was selling filling adaptors that uses a hose between the can and the gas tank. This allowed the can to be turned horizontal allowing all the butane to be used. These cans are designed to be used in a horizontal position with the notch facing a certain direction (can't remember if it's up or down). Inside the can there's a small tube from the nozzle that bends 90 degrees towards the "down" side of the can. 

At any rate, get in touch with Royce and see if he still has any of those adaptors left.


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## Pete Thornton (Jan 2, 2008)

can't remember if it's up or down 

Be nice to know! I spent 10 minutes searching the web for a manual for one of those stoves, but no dice. I have one of Royce's adaptors, but I usually use it upside down; I didn't realise there was a horizontal option. 

Now, where's that 'empty' can I just put in the trash. Maybe time to try it horizontal... 


_[2 minutes later]_ OK - found it. Ans: Notch down.

The top of the butane can has a notch in the ring, used for clipping the adaptor to the can or (presumably) for attaching the can to a stove. 

I took my 'empty' can outside with the 'Royce adaptor' and opened the valve with the notch up and notch down. When the notch was up, I got butane gas. *When the notch was down, I got some butane liquid as well as the gas! * 
_Thanks for the hint, Dwight!_


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## Bill4373 (Jan 3, 2008)

what butane canisters are you using??


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## Dwight Ennis (Jan 2, 2008)

what butane canisters are you using??Mine are from the Asian supermarkets - about the size of a can of Krylon spray paint. Around $1.00 to $1.25 a can.


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## Jerry Barnes (Jan 2, 2008)

I got some of those at Cabela's.


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## rrdude (Feb 21, 2008)

what butane canisters are you using?? 


They are camping stove canisters. (PRIMUS, I believe.) They have a 3/8"(?) threaded nipple on top. The adapter screws onto this and you turn the canister upside down and push the adapter onto the fuel tank's valve.


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## cabforward (Feb 18, 2008)

For the Asian cans there is a 90 dergeree plastic pipe that is angled to the side of he can were the cut out on the rim is located. 
The cut out is ment to go down when in an Asian stove. 
When a can is low i eather hold a tender on its side or a small loco so that can is flat. 
Hope this helps 
matt


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## Jeff Williams (Jan 8, 2008)

Perhaps you have noticed that the butane can gets cooler as you drain butane out of it. There is a significant change in the pressure in the can that comes with this drop in temperature. At some point, the pressure in the butane can and the pressure in the loco's butane tank equalize, so no more butane is transferred. The pressure vs temperature relationship for butane and other gases and gas mixtures is shown in:


http://www.southernsteamtrains.com/notes/bestfuelgas.htm 


You can crack open the fuel valve on the loco a tiny amount while you are filling it which will reduce the pressure in the loco fuel tank to facilitate transfer


You can also put the can into a bath of warm (not hot) water a few inches deep which will increase the pressure in the can.

Earlier contributors have correctly noticed that you can never get the last of the butane out of the Korean stove fuel cans without turning the can horizontally, however, you can also buy the much more expensive butane cans that are intended for the use of refilling various butane-fueled devices (generally they are smaller in diameter than the Korean stove fuel cans and have a needle filler outlet) which will fully empty vertically.


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## Pete Thornton (Jan 2, 2008)

They are camping stove canisters. (PRIMUS, I believe.) They have a 3/8"(?) threaded nipple on top. 

Nope - those are a mix of propane/butane (70/30 -ish I believe.) 

Asian butane comes in a 220g cartridge - like these: (you can see the notch on top.)


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## rrdude (Feb 21, 2008)

The equalization of pressure is what I'm referring to. My K-28's fuel tank is large enough to take a good portion of my canister. Then I need to switch to a fresher one that has a higher pressure. Eventually I'm stuck with a bunch of canisters with fuel in them but very little pressure. 

If I crack the valve on the fuel tank, will I not be releasing as much gas as I'm trying to put in? 

I guess i can try to heat up the ones with lower pressure to try to build it up some. 

= = = 

Question: With the Camp Stove types that you invert to use, am I transferring Gas or Liquid? Do they also have a tube like the asian types do?


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## msimpson (Jan 5, 2009)

"I guess i can try to heat up the ones with lower pressure to try to build it up some." 

Can you put me down as a beneficiary on your life insurance first? 

If you WARM a can with warm water, you will increase the pressure and may get a little more out. If you HEAT a can with a flame or otherwise, you have a BOMB. The K-28 cost how much? And you will save how much if you get every speck of gas out? Less the damage to yourself , your engine, and whatever else from the fireball and flying metal? 

Gas cans are not made to take the stresses of heated gas -- butane, propane, or a mix. Old threads have lengthy discussion of what happens to the pressure in a fuel tank as heat increases. Please don't. 

If there is very little pressure, and shirt sleeve temperatures, then there is very little fuel. Don't sweat the small stuff. 

If you meant, warm it. Sure. Or spend more time with smaller engines. 

Regards, happy and safe steaming, Mike


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## RimfireJim (Mar 25, 2009)

Posted By rrdude on 21 Oct 2009 11:01 AM 
Eventually I'm stuck with a bunch of canisters with fuel in them but very little pressure. 

That can't be. The pressure inside the can is dictated by the vapor pressure of the fuel, which itself is a function of temperature. As long as there is any liquid at all in the can, the pressure will be the same as another can that is almost full, if the two cans are at the same temperature. The pressure drops only when all the liquid is gone and you start to draw off gas (vapor). If you are down to that point, the amount of fuel we're talking about is minuscule.


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## RimfireJim (Mar 25, 2009)

Posted By rrdude on 21 Oct 2009 11:01 AM 
The equalization of pressure is what I'm referring to. My K-28's fuel tank is large enough to take a good portion of my canister. Then I need to switch to a fresher one that has a higher pressure. Eventually I'm stuck with a bunch of canisters with fuel in them but very little pressure. 

If I crack the valve on the fuel tank, will I not be releasing as much gas as I'm trying to put in? 

I guess i can try to heat up the ones with lower pressure to try to build it up some. 

= = = 

Question: With the Camp Stove types that you invert to use, am I transferring Gas or Liquid? Do they also have a tube like the asian types do? 
A1) No, you are putting in liquid and releasing gas. Major difference in density, therefore major difference in heat capacity.


A2) for probably more than you want to know about fuel canisters, see this excellent site: http://www.bushwalking.org.au/FAQ/F...m#Canister


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