Assessment of the condition of japanese festival, a wooden sculpture by Tanaka Eisaku

Les na prostem je izpostavljen delovanju raznolikih dejavnikov razkroja, še posebno glivam. Nekatere lesne vrste so bolj odporne na glivni razkroj kot druge. V Kostanjevici na Krki že 60 let deluje forma viva, kjer so razstavljeni kipi, izdelani pretežno iz hrastovega lesa. Tanaka Eisaku, japonski kipar, je izdelal najstarejši kip z naslovom Japonski festival na prvi kostanjeviški Formi vivi leta 1961. Po 60 letih zunanje izpostavitve smo kip vizualno pregledali in ocenili njegovo stanje z uporabo rezistografa in vlagomera. Iz kipa smo izolirali nekaj vzorcev, jih preiskali s FTIR in XRF spektroskopijo, vzorcem določili gostoto s piknometrom GeoPyc in jih analizirali z lasersko in digitalno mikroskopijo. Na kipu je opaziti znake glivnega razkroja, izletne odprtine insektov in poškodbe zaradi delovanja ptic. Ocena razkrojenosti z rezistografom je pokazala, da je les razkrojen predvsem na čelih in v sredici. Poleg tega je na nekaj mestih močno razkrojena tudi beljava. Les je bil v zadnjih letih obdelan s površinskim premazom, po drugi strani v lesu ni bilo mogoče zaznati ostankov biocidov. V primeru, da želimo kip ohraniti zanamcem, ga je treba ustrezno konzervirati.Wood in outdoor applications is exposed to various decay factors, of which fungi are the most important. Some wood species are more resistant to fungal decay than others. Forma Viva in Kostanjevica has been exhibiting sculptures made mainly of oak wood for 60 years. The oldest sculpture is the work of Tanaka Eisaku entitled “Japanese Festival”. After 60 years, the condition of the sculpture was examined with a resistograph and a moisture metre. Several samples were isolated from the sculpture and examined with FTIR and XRF spectroscopy. The density of the samples was determined with GeoPyc and analysed in detail with laser and digital microscopy. Signs of fungal attack, as well as insect and bird damage can also be seen on the sculpture. The resistograph analysis showed that the wood is mainly decayed in the axial planes and in the core. In addition, the sapwood is severely decayed in some areas. The wood has been surface-coated in recent yearshowever, there is no biocide residue in the wood. If the sculpture is to be preserved for posterity, it must be properly conserved