FIST2 Adapter – How to Prevent O-Ring Damage

TAGinn received a lot of feedback from users about the central O-ring on the FIST2 adapter getting blown out or damaged. And yes, they know exactly why this happens – and how to avoid it.

Here’s what’s going on:

CO₂ is a tough gas. When FIST2 is under CO₂ pressure for 30–40 minutes, the gas fills the micro-pores of the O-rings. This causes them to slightly expand and lose their original shape temporarily.

The critical moment:

If you remove the used 12g CO₂ cartridge and immediately install a new one and pressurize again — before the O-rings have returned to their original shape — the central O-ring can pop out, get deformed, or even rip.

What to do:

1. After 30–40 minutes under pressure, degas the system and remove the used CO₂ cartridge.

2. WAIT 5–10 minutes. Let the O-rings “cool down” and return to their original form.

3. Only then insert the new cartridge and repressurize.

This small pause can save you a lot of frustration and O-rings.

TAGinn always working on improving our systems, but until then — follow this tip and your FIST2 will stay reliable much longer.