Inflation Bags

If the average adult human can expel a maximum of less than 4 litres of air per breath and a packraft has an inflated volume of over 300 litres, then to inflate a packraft by mouth would take over 75 maximum-capacity breaths. This is an unpleasant and time-consuming process that leads to dizziness and tingling fingers – believe me – I tried it once and gave up before my packraft was even half inflated.

Luckily, there is a lightweight solution to this problem: the inflation bag. See how it works in this video:

If you own a modern inflatable camping mattress, there’s a good chance you already have an inflation bag that can be adapted to fit your packraft’s valve, but if not, you can make your own without much effort.

The simplest and lightest inflation bag I made was simply a large plastic garbage bag with a short piece of rubber hose taped to a hole in the bottom of the bag. The rubber hose fits into the packraft’s Boston valve, and with the trash bag you can scoop up a lot of air all at once. Total cost: a few cents. The main drawback of this type of inflation sack is that the thin plastic bag is not very durable.

Inflation Bag Fabric:

There are two good options for inflation bag fabric: TPU-coated nylon (described here), and silnylon*. TPU-coated nylon has the advantages of being heat sealable (no sewing required) and more durable, while silnylon is lighter. Either one can also be used to make drybags, so your inflation sack can double as a drybag for storing your gear while paddling.

If weight is your ultimate concern and you have access to a sewing machine, choose silnylon. If durability is important to you and/or you don’t want to do any sewing, choose TPU-coated nylon.

You can make an inflation bag of any size by simply folding a rectangle of fabric in half and bonding two sides together to form a sack. Then make a hole in the bottom of the sack and glue in a short piece of rubber or plastic hose sized to fit into your packraft’s Boston valve (7/8″ OD works well – that’s between 22 and 23 mm). There’s no need to match the metric threads in the valve – just shove the hose in.

*Silnylon is nylon fabric that is coated or impregnated with silicone, which makes it waterproof and nearly airtight – ideal for many backcountry uses, such as lightweight tarps, pack covers, and rain ponchos. If you’ve bought a tent in this millennium, the fly is probably made out of silnylon. The amount of silicone applied to the fabric is indicated by the height of water it will support without leaking excessively, determined by a standard test and reported in millimetres… this doesn’t matter too much for an inflation bag, but becomes important for things like tents and groundsheets. Silnylon can’t be heat sealed like TPU-coated nylon, so it’s usually sewn and then the seams are sealed with tape or glue.