Valve sealant

Valve sealant was a substance used by Starfleet in the 22nd century.

In 2151, as the Starship was preparing to launch, Malcolm Reed became quite annoyed that Starfleet delivered to him a case of valve sealant instead of the plasma coils which he had requested, fearing that he would not be able to bring Enterprise's weapons online by the time they launched. 

Later that year, Lieutenant Reed and Commander Charles Tucker used valve sealant to repair microscopic hull breaches sustained on  after an impact with a microsingularity. 

In 2152, when Archer and Ensign Mayweather were being held in the Tandaran Detention Complex 26, Mayweather sardonically suggested that the food the guards were serving them would be better used as a valve sealant for Commander Tucker.