Colour changes of weathered wood surfaces before and after treatment with iron (II) sulphate

Lesar, Boštjan (author), Humar, Miha (author), Osvald, Florjan (author)

Outdoor wood is exposed to various factors that can be described as weathering and cause the wood to grey. The ageing processes can vary greatly depending on the exposure. Parts of wood that are not exposed to external factors, e.g. under the overhanging, are less exposed, and the weathering process is therefore slower. This can be accelerated by solutions based on iron ions. In this way, the wood greys quickly and evenly. However, after iron treatment, the colour also depends on the previous exposure of wood to weathering. In our study, the colour change was observed as a function of weathering time. Before treatment, the samples were exposed to outdoor weathering for different periods of time and then treated with a 5 % solution of pure iron (II) sulphate and commercial iron (II) sulphate. It was determined that the pre-weathering time affected the final colour change, as the samples exposed for five weeks before treatment have comparable colour to naturally weathered wood. At the beginning of exposure, iron (II) sulphate limits mould growth, but after two months, staining fungi develop on the treated samples as well. The growth of blue stain fungi on the treated samples did not significantly affect the colour and visual appearance of the wood treated with iron-based solutions.

• Language: English
• Keywords: ageing, weathering, iron (II) sulphate, colour change, blue stain fungi
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 5-17
• Numbering: Vol. 75, iss. 1
• PID: 20.500.12556/RUL-154871
• UDC: 674.07
• ISSN on article: 0012-6772
• DOI: 10.5552/drvind.2024.0148
• COBISS.SI-ID: 187834371

Note

KLJUČNE BESEDE: staranje, izpostavljenost vremenskim vplivom, železov (II) sulfat, sprememba barve, glive modrivke

• Publication date in RUL: 07.03.2024

Record is a part of a journal

• Title: Drvna industrija : scientific journal of wood technology = znanstveni časopis za pitanja drvne tehnologije
• Shortened title: Drv. ind.
• Publisher: University of Zagreb, Faculty of Forestry and Wood Technology
• ISSN: 0012-6772
• COBISS.SI-ID: 2858754

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Croatian
• Title: Promjena boje površina drva izloženih vremenskim utjecajima prije i nakon tretmana željezovim (II) sulfatom

Abstract

Drvo za vanjsku uporabu izloženo je različitim čimbenicima koji se mogu opisati kao vremenski utjecaji, a uzrokuju sivljenje drva. Procesi starenja mogu uvelike varirati ovisno o izloženosti drva tim utjecajima. Na dijelovima drva koji nisu izravno izloženi vanjskim čimbenicima, npr. ispod prevjesa, proces starenja je sporiji. Taj se proces starenja može ubrzati otopinama na bazi iona željeza tako da drvo brzo i ravnomjerno posivi. Međutim, boja nakon tretmana željezom također ovisi o prethodnoj izloženosti drva vremenskim utjecajima. U ovom smo istraživanju promatrali promjenu boje kao funkciju trajanja izloženosti drva vremenskim utjecajima. Uzorci su prije tretmana različito vrijeme bili izloženi vremenskim utjecajima, a zatim su tretirani 5 %-tnom otopinom čistog željezova (II) sulfata i komercijalnog željezova (II) sulfata. Utvrdili smo da je prvotna izloženost vremenskim uvjetima utjecala na konačnu promjenu boje jer su uzorci koji su bili pet tjedana izloženi vremenskim utjecajima prije tretmana imali sličnu boju kao i prirodno drvo izloženo vremenskim utjecajima. Na početku izlaganja željezov (II) sulfat ograničavao je razvoj plijesni, ali su se nakon dva mjeseca izlaganja i na tretiranim uzorcima drva razvile gljive promjene boje. Razvoj gljiva plavila na tretiranim uzorcima nije znatnije utjecao na boju i vizualni izgled drva tretiranog otopinama na bazi željeza.

• Keywords: starenje, izlaganje vremenskim utjecajima, željezov (II) sulfat, promjena boje, gljive plavila