An apparatus for longitudinal fluid impregnation of a log comprising a cap for enclosing one end of a log, the cap having a rear wall and a peripheral side wall so as to define a fluid treatment zone, members inserted through apertures in the side wall of the cap for locking it to the log, a first ring for encircling the log and abutting the said members, a self-sealing compressible means for encircling the log and abutting the first ring, a second ring for encircling the log and abutting the sealing means, the second ring having or associated with means for retaining it against movement on the log, means for exerting pressure on an end of the log so that compression will be applied to the sealing means, and means for introducing a pressurised log-treating fluid into the treatment zone for the fluid to be forced along within the log.
