Describes an accelerated (262-day) polyethylene glycol treatment utilized in Bulgaria for treating a 4.15m-long dugout Thracian canoe of Mountain ash (Fraxinus excelcior). The method involves preliminary wetting in a 1% polyethylene glycol 1500 bath with 0.2% sodium pentachlorophenolate as a biocide, gradually increasing the PEG 1500 concentration to 30% and the biocide concentration to 0.5%; as the concentration of PEG was increased to 40%, 20% PEG 4000 was included; as the concentration of PEG was increased further, the proportion of PEG 4000 was raised and glycerine added in amounts ranging from 0. 5% up to 2%. By the end of the treatment, the temperature was elevated to 64°C, PEG concentration was stabalized at 85% and cooled to 50°C (122°F); cleaning by means of heat, ethanol and methylated spirits is described, as well as post-cleaning surface treatment with Cosmoloid microcrystalline wax, Paraloid B 72 and toluene.