Sunday, October 14, 2012

Refilling 1 lb. Propane Cylinders

1 lb. propane cylinders are very handy and great at powering camping stoves and camping lanterns. In times of emergency these two appliances can be life savers and very comforting. The camp stove can cook your meals as well as sterilize drinking water and at night the propane lantern is hard to beat with a single mantle lantern putting out nearly the equivalent of a 100 watt light bulb. The trouble is these small cylinders don’t last forever. After 4-5 nights for a lantern and a dozen or so meals on the camp stove they expire. Because they don’t run things forever you have to stock dozens of them and that’s very expensive today.

Fortunately, there are a number of companies that make refill adapters so we can refill these smaller cylinders repeatedly from larger cylinders like those used for your BBQ or an RV.

The process of refilling the 1 lb. cylinders is very simple, just do it outside in case of a propane fitting leak.

Here’s a photo of one of my 30 lb. RV propane tanks used for this demonstration.

Here’s the refilling adapter I used. They are durable and very simple. You can purchase one at, or many other outlets on the web.

I’m using a 32 oz. kitchen scale to show the weights before and after. In this photo is a totally empty cylinder now weighing 15 ounces. Notice the frost on the side of the tank. In order to completely fill the cylinder with 1 lb. of propane you must put the cylinder in your freezer for about 1 hour before refilling.

Here’s the small cylinder attached and filling from the large tank. Notice the large tank must be upside-down. Also the tank is resting on a couple scrap 4x4’s so I can easily get to the main valve to turn it on and off. The time it takes to fill one cylinder about 60 seconds. There’s no weighing involved or timing how much propane goes in. Just open the valve, after a few seconds the small cylinder is full, turn off the large cylinders valve and disconnect the small cylinder.

Here’s the cylinder after filling and as you can see it took just slightly more than 1 lb. of propane from the big tank for a total weight of just under 32 ounces, close enough for me. I just saved $3.00 and now have a full cylinder for my camp stove or lanterns.

When you get your adapter follow precisely the directions supplied with it.

Refill cylinders outdoors. Any mishap of say a broken valve or dropping the large cylinder with the small one attached there is the possibility of a serious leak. All propane is under very high pressure, between 250 and 275 PSI.

Place the 1 lb. cylinders in the freezer for about an hour. The cold will allow filling the cylinder with 1 lb. of propane.

I have tried to fill room temperature cylinders but could only get 6-7 ounces in them. Although this will be fine if the grid is down and you don’t have an operating freezer, you’ll just have to refill more often.

Do not store propane cylinders in your garage or in your house.


  1. Thanks for showing this - we have an adapter but have not tried it yet. What do you suggest for proper propane cylinder storage?

  2. Once again, you've provided another great and informative post!

    It would drive me completely NUTS to see all those little bottles being thrown out, what a WASTE...of resources and money! We've got a bunch in the shed so I think we'll get that little doo-dad and start filling those up again. We used them when the ice storm hit in 2009 and it would be nice to have some more filled just in case.

    Thanks again :)

  3. I've used one of these adapters for about 5 months now. I just put my tanks in the fridge for about 30 minutes and it works pretty good.

    I use them to power a little two burner camp stove that I cook 75% of my meals off of. They last for about 2 weeks using a texsport stainless steel cook-set. I cook exactly what I need for each meal. The 20lb bottle has yet to run out and it looks like I'll get another 5 or 6 refills before it does. $20 for 6 months or more of cooking isn't bad at all.

    It's a great money saver. My power bill was the lowest I've ever seen by far because of this. My electric house stove just killed me each month before I did this.

  4. 2 Tramps,
    This is very easy to do so give it a try. As for storing use the same method as the cylinder manufacturer recommends. I would not store them in your garage, apartment or inside your home. Store in a shed. If you don’t have a ventilated shed then the best option is in your trunk of your vehicle or topper if you have a truck. I’d rather lose my vehicle than my home should a valve begin to leak.

  5. Carolyn,
    This is what being independent is all about, making use of common low tech methods to save money. Refilling 1 lb. cylinders is very simple to do. Give it a try it a try.

  6. Anon,
    Good for you! Save money everywhere you can and this is a simple way to do it as you have already proved! A 20 lb. tank should give you about 20 refills.

  7. Store them the way that retailers store the 20# tanks: outside, in a vented enclosure, away from sunlight, air intakes for the building and any possible sources of ignition.

  8. There used to be refllable 20oz (ounce) I think cylinders available. Much more durable than current crop of disposables. Both of mine have long since lost their labels, but have a valve to open while filling. I wonder if same could be does on safety vent to ensure a good liquid charge.

  9. I don’t recall seeing a 20oz cylinder on the market. The Schrader valve on the disposables as I understand it is for venting pressure while filling but I would leave that to people with the proper filling equipment and training. Refilling the way it’s shown gives me 1 lb. verified with a scale every time so far. If I were to have ANY trouble refilling one I would stay on the safe side and junk that cylinder. An undetected, slow leaking cylinder valve is very dangerous.

  10. Will definiately have to try this! Great post!

  11. An unused rolled out condom placed on the neck of the cylinder with a rubber band will tell you if your valve is leaky! Or you can just do the flame test!...Tim

  12. anon,
    Interesting leak detector! A very slow leak wouldn't ignite with a match but over a few days the condom would fill. I second the motion for using a new condom :-)

  13. *huh*

    That is fantastic. Definitely need to search around your older postings much more.

    I would have thought the freeze would be detrimental as expansion in the tank occurs later on.

    Must already be factored into the construction of the tank.



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