Deformable sealing plug and process for plugging a cavity using such a sealing plug

A process for plugging a cavity using a sealing plug, the sealing plug comprising an envelope configured to be deformed incompressibly, the envelope delimiting a hollow internal space and being provided with at least one orifice capable of making said hollow internal space communicate with an outside of the envelope, a rod which is configured to slide through the envelope and extend on either side of said envelope, the rod comprising a first end provided with a head configured to exert a compressive force on the envelope in order to deform the envelope when a second end of the rod is moved so as to pull the head against the envelope, and a viscous seal arranged in the internal space of the envelope, wherein the sealing plug is configured such that the viscous seal is at least partially expelled from the envelope through the at least one orifice when the envelope is deformed by the head of the rod, the process comprising:

• a positioning step for inserting the sealing plug into the cavity such that the second end of the rod is accessible from outside the cavity;
• a deformation step for moving the second end of the rod so as to pull the head against the envelope and exert a compressive force to deform said envelope until the envelope at least partially plugs the cavity and at least some of the viscous seal is expelled from the envelope through the at least one orifice;
• and
• a polymerization step for allowing the viscous seal expelled from the envelope during the deformation step to polymerize so as to obtain complete leaktightness of the cavity.