1. See the assembly instructions for your particular kiln.
2. The hinge of any kiln must be adjusted so that the expansion caused by the heating process has room to expand.
3. An improperly adjusted hinge can damage the rim and/or lid but also makes the brick of the rim compress against  the brick of the lid.
4. CAUTION: Do NOT attempt to disengage the spring hinge without first reading the detailed assembly instructions. The spring is under great pressure and could cause severe injury if it is removed under pressure. RELIEVE ALL SPRING TENSION BEFORE REMOVING!
5. CAUTION: It is critical that the hinge bar sits in the bottom of the slot. This is to allow the lid to rise and lower slightly as the kiln heats and expands with out putting stress on the lids connection points and potentially damaging the lid.

See this video on how to adjust the spring hinge properly