FlipFuel Review: Fuel Canisters Rejoice!

Gearing up for a bikepacking trip is always about finding a balance between size, weight, and usefulness for all packable items. I can't tell you how many times I've stood in the store debating on what size of fuel canister I should buy. Big for the fuel cost savings, or small because you are only going out for a few nights. Do I have enough? Do I have too much? Maybe you're like me and only the small size fits inside your ultra-compact cookset and anything else means something must be left behind to make room.

At any given time, my gear shelf has an assortment of canisters with an undetermined amount of fuel left in each. I constantly tell myself I need to weigh each canister to calculate how much fuel remains. I need to use these all up, but when? Each time I pack for a quick trip, I don't bother to bring one, because they are big and bulky. If I only had a way to consolidate all these partially used canisters. This would save me a few bucks and prevent some from having to be recycled at the end of each season.

Thankfully, Arizona-based scout leader, Eric Flottmann was also tired of leaving half-full canisters at home. He paired up with fellow Arizona entrepreneur, Frank Healy to come up with a device to solve this problem. Enter FlipFuel. Similar transfer valves are around, but no one has refined a product to this degree or of this quality. Their hashtag #DontPackaHalfie says it all.

Simply put, this nifty little 35-gram gadget allows fuel to safely flow from one canister to another. It's a nice machined block of aluminum in red and white anodizing, a brass-looking vent button, and plastic threaded caps to protect the recessed fittings and has small o-rings inside to ensure a good seal. The folding valve handle is similar to the ones found on camping stoves. Mine came neatly packaged with simple-to-understand instructions and two cute stickers.

The secret of this device is a simple physics trick by creating a pressure difference using temperature. As adults, we should all know that heating air expands it. You probably learned this lesson the first time you reheated that plastic container of leftover pasta in the microwave and had to clean up the brutal aftermath. By using temperature we can create a pressure difference between canisters thus making the fuel transfer from the warm one to the cold one.

A common type of stove that cyclists use is called a “canister stove” because it runs on pressurized canisters of Iso-Pro fuel. This fuel is usually an 80/20 blend of isobutane and propane that burns clean and delivers superior performance throughout the life of the canister and in colder temperatures.

The Rules

Using the FlipFuel is very easy, but there are a few key things you need to know and prepare before all this flipping happens. You can transfer fuel between any brand of fuel canister, but there are some simple things to keep in mind: 1. Do not overfill a canister 2. Only use canisters that contain the same kind of fuel 3. Only transfer fuel in a well-ventilated area and 4. Properly dispose of empty canisters.

To ensure that you don't overfill the canister, you must know what the canister weight should be when full. It's as simple as looking at the side of the tank. Most brands come in three standard sizes: small, medium, and large. Be aware that there are two weights shown on each can. The NET is the empty canister and the GROSS is the weight of the can full of fuel. The gross weight is what you need when topping up your canisters with the FlipFuel.

It's easiest to have an accurate kitchen digital scale on hand. These can be bought for as little as $10-15 (USD) at local discount stores. The "floating" method shown on the side of the containers is far from accurate and not recommended for this procedure. TIP: The FlipFuel is 35 grams. Add this to the gross weight of the canister you are filling. For example, the medium canister is 374g full, and 409g with the FlipFuel attached. Now let's begin flipping some fuel around.

How it Works

Place the receiving canister that you want to fill on ice or in a freezer, and the source canister near a heat source. 5-10 min should be sufficient but remember it's safer to freeze one canister more than overheat the other. Do not place it on direct heat, obviously. We are not trying to pressurize the source tank, just create a reasonable pressure difference between the two. One in the freezer and one in the sunshine or on a warm window sill is all you need.

Ensure the FlipFuel valve is closed and the dust caps are off and place the two canisters side-by-side. The order in which the canisters are attached is up to you. Screw FlipFuel onto the warm canister to the "OUT" fitting. Flip the cold canister upside down and screw it onto the top which is the "IN" fitting. Flip the entire assembly over so the cold canister is on the table. The fuel transfer rate will depend on the size of the canisters and how full each canister is. Knowing how long to leave the valve open will take a little experimenting. Start by only opening the valve for maybe 5-10 sec. Remove the cold canister and weigh it on your scale. Do a little math from your notes to see how much was transferred during that time. In practice, I found it best to remove the supply can, and weigh the can you're filling with the FlipFuel still attached, this is why I mentioned adding 35 grams to your gross canister weight.

Repeat until you reach the weight as indicated on the canister. You won't get every drop of fuel out of the source canister, but you'll be close. I had enough to boil enough water for a cup of afternoon tea while transferring a few other canisters. Maybe you could do the same? Inquire at your local recycler about how to dispose of empty canisters. For safety reasons, most recyclers require them to be punctured, releasing the remaining pressure and off-gas any fumes before disposal.

Ugh. I Overfilled.

Filling small canisters from a large one will only take a short time and the risk of overfilling is high. If you have overfilled a canister, just use the built-in FlipFuel bleeder to vent some fuel off. Nice. I shouldn't have to say this, but you need to be in a well-ventilated area. Re-weigh the canister to ensure you're good. I doubt a canister would rupture, but over-full and over-pressured may result in your stove acting up for a while, or so I've read... I haven't tested this in real life.

Wrapping Up

While I #DontPackaHalfie that often, I have a collection of them and the FlipFuel is a great little device to consolidate all my halfies I don't dare take for fear of running out of fuel. It will also be more economical and environmentally responsible by purchasing large containers and only keeping a few smaller ones on hand for trips. This way I can ensure I always have a full can of fuel in my cookset including some room for my precious coffee grinder. It's a well-designed affordable device at $35 (USD) that every camper should have in their kit. Get it here.

Also, check out my how-to video on using the Flip-Fuel.