Fuel Canister Cap? Or No Cap?

Use the cap: it protects the canister threads and keeps dirt out!

Many long-distance hikers do not carry the plastic cap that comes with the fuel canister in order to save about 2 grams of weight. However, the canister cap serves a valuable purpose by protecting the threads of your canister and keeping dirt from entering the top of the fuel canister.

Damaged threads can damage your stove threads when the canister is attached. Cross threading a stove is one of the most common reasons for stove replacement on the trail (which is both expensive and inconvenient)!

Clean Canister Threads

Clean Threads

Dirty Fuel Canister Threads

Dirty Threads

Any dirt in the top threaded area of the canister will enter your stove when it is attached, which increases the chances of clogging the stove and reducing performance.

Canister Cap Weight

You save about 2 grams (the weight of about 2 paperclips) by leaving the cap behind, but the risk to damaging your stove is relatively high. Therefore, I recommend using the canister cap to protect your canister and stove from damage.