An unusual surface change on the Viking ships exhibited in Roskilde

Morten Ryhl-Svendsen; Lars Aasbjerg Jensen; Anette Hjelm-Petersen

An unusual surface change on the Viking ships exhibited in Roskilde

Bidragets oversatte titel: En usædvanlig overfladeændring på vikingeskibene udstillet i Roskilde

Morten Ryhl-Svendsen, Lars Aasbjerg Jensen, Anette Hjelm-Petersen

Nationalmuseet

Det Kongelige Akademi Konservering

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

Abstract

Fem 1000 år gamle Vikingeskibe, som er blevet konserveret ved imprægnering med PEG, har i over 50 år været udstillet i en udstillingshal med et stort vinduesparti, der tillader dagslys som hovedlyskilde, om sommeren med spidsbelastninger på op til 30.000 lux. Et uforklaret fænomen er blevet observeret på skibenes træplanker, hvor et tyndt hvidtblåligt lag dannes på overfladerne, fordelt overalt, men mest intenst på områder med retning mod vinduer. Måling af lys og UV viste årlige lysdoser på mellem 2 og 8 Mluxtimer. Blå-uld skalaer falmede til trin 5 på et år. Farvemålinger af afrensede områder, som derefter blev lyseksponeret i udstillingen viste en farveændring (CIELAB1976 Delta E) på omkring 3 efter et år, og omkring 7 efter tre år. Et UV-filter forsinkede denne udvikling. Fænomenet blev eftergjort på PEG-imprægnerede træprøver ved accelererede lys- og UV-eksponeringstest. Det antages, at misfarvningen skyldes lys og UV-stråling, og at UV-andelen mindst er ligeværdigt medvirkende, og sandsynligvis den primære årsag. En årlig grænse for lyseksponering på 0,6 Mlux-timer, for lys uden UV-indhold, blev anbefalet.

Bidragets oversatte titel	En usædvanlig overfladeændring på vikingeskibene udstillet i Roskilde
Originalsprog	Engelsk
Tidsskrift	Meddelelser om Konservering
Vol/bind	2023
Udgave nummer	2023
Sider (fra-til)	5-14
Antal sider	10
ISSN	0106-469X
Status	Udgivet - 2023

Emneord

PEG; lysdosis; UV-stråling; blue-wool standard; dagslys; nedbrydning; præventiv konservering.

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Citationsformater

@article{b5ce6516ae444a3bb43891647cb746dd,

title = "An unusual surface change on the Viking ships exhibited in Roskilde",

abstract = "Five Viking ships, conserved with PEG, have been displayed for over 50 years in an exhibition hall with a large window section. Daylight could reach peak levels of up to 30,000 lux in summer. An unexplained phenomenon of a thin bluish-white layer forming on surfaces has been observed on the ship planks. It is distributed everywhere but most intensely on surfaces facing the windows. Light and UV were suspected to cause this, and the phenomenon was investigated so that a sufficient light level policy can be formulated. Monitoring of light and UV revealed annual light doses between 2 and 8 Mlux-hours. Blue-wool scales faded to step 5 in one year. Color measurements of areas cleaned and then exposed to exhibition light showed a color change (CIELAB1976 Delta E) of about 3 after one year, and about 7 after three years. A UV-filter retarded this change. The phenomenon was imitated on PEG impregnated wood samples by accelerated light and UV exposure tests. It is assumed that the discoloration is due to light and UV-radiation and that UV is at least equally contributing, and probably the main driver of it. An annual light exposure limit of 0.6 Mlux-hours with no UV-content was recommended.",

keywords = "PEG; lysdosis; UV-str{\aa}ling; blue-wool standard; dagslys; nedbrydning; pr{\ae}ventiv konservering., PEG, Light dose, Preventive conservation, Deterioration, Daylight, Blue-woorioration, UV radiation",

author = "Morten Ryhl-Svendsen and Jensen, {Lars Aasbjerg} and Anette Hjelm-Petersen",

year = "2023",

language = "English",

volume = "2023",

pages = "5--14",

journal = "Meddelelser om Konservering",

issn = "0106-469X",

publisher = "Nordisk Konservator Forbund",

number = "2023",

}

TY - JOUR

T1 - An unusual surface change on the Viking ships exhibited in Roskilde

AU - Ryhl-Svendsen, Morten

AU - Jensen, Lars Aasbjerg

AU - Hjelm-Petersen, Anette

PY - 2023

Y1 - 2023

N2 - Five Viking ships, conserved with PEG, have been displayed for over 50 years in an exhibition hall with a large window section. Daylight could reach peak levels of up to 30,000 lux in summer. An unexplained phenomenon of a thin bluish-white layer forming on surfaces has been observed on the ship planks. It is distributed everywhere but most intensely on surfaces facing the windows. Light and UV were suspected to cause this, and the phenomenon was investigated so that a sufficient light level policy can be formulated. Monitoring of light and UV revealed annual light doses between 2 and 8 Mlux-hours. Blue-wool scales faded to step 5 in one year. Color measurements of areas cleaned and then exposed to exhibition light showed a color change (CIELAB1976 Delta E) of about 3 after one year, and about 7 after three years. A UV-filter retarded this change. The phenomenon was imitated on PEG impregnated wood samples by accelerated light and UV exposure tests. It is assumed that the discoloration is due to light and UV-radiation and that UV is at least equally contributing, and probably the main driver of it. An annual light exposure limit of 0.6 Mlux-hours with no UV-content was recommended.

AB - Five Viking ships, conserved with PEG, have been displayed for over 50 years in an exhibition hall with a large window section. Daylight could reach peak levels of up to 30,000 lux in summer. An unexplained phenomenon of a thin bluish-white layer forming on surfaces has been observed on the ship planks. It is distributed everywhere but most intensely on surfaces facing the windows. Light and UV were suspected to cause this, and the phenomenon was investigated so that a sufficient light level policy can be formulated. Monitoring of light and UV revealed annual light doses between 2 and 8 Mlux-hours. Blue-wool scales faded to step 5 in one year. Color measurements of areas cleaned and then exposed to exhibition light showed a color change (CIELAB1976 Delta E) of about 3 after one year, and about 7 after three years. A UV-filter retarded this change. The phenomenon was imitated on PEG impregnated wood samples by accelerated light and UV exposure tests. It is assumed that the discoloration is due to light and UV-radiation and that UV is at least equally contributing, and probably the main driver of it. An annual light exposure limit of 0.6 Mlux-hours with no UV-content was recommended.

KW - PEG; lysdosis; UV-stråling; blue-wool standard; dagslys; nedbrydning; præventiv konservering.

KW - PEG

KW - Light dose

KW - Preventive conservation

KW - Deterioration

KW - Daylight

KW - Blue-woorioration

KW - UV radiation

M3 - Journal article

SN - 0106-469X

VL - 2023

SP - 5

EP - 14

JO - Meddelelser om Konservering

JF - Meddelelser om Konservering

IS - 2023

ER -