Protective Properties of Traditional Wood Paint Based on Cattle Blood

ABSTRACT

In the past, cattle blood was used for painting in central Europe mainly for interior wooden elements. Unfortunately, this common wood-coating technique of the past had vanished during the 20th century and only many misinformed opinions are left about this coating’s purpose and its effects on wood durability. Three different recipes were used for beech and pine sapwood treatment, which were tested for their durability against wood-rotting fungi and termites. The fire retardancy of blood-based paints and its color change during the hardening process was determined as well. Over the course of time the bright brick red color of the coating turns a dark brown color. The coating surface layer did not protect the wood against either white- or brown-rot fungus; it is rather a source of nutrients necessary for a fungi degradation activity. The specimen treatment with the blood-based paint did not avoid termites feeding on wood, however the overall mortality was reached at the end of the test. The higher pH of the treated wood and/or available amount of micronutrients could be plausible explanations. Although fire retardancy of the coating was not proved, flame-exposed spruce wood with the coating did not show significantly improved fire resistance compared to untreated wood.

KEYWORDS:

• Cattle blood
• color
• fire retardant
• surface treatment
• termites
• wood-rotting fungi

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The paper was supported by NAKI project “Historical Timber Structures: Typology, Diagnostics and Traditional Wood Working” [Reg. No. DG16P02M026], provided by the Ministry of Culture of the Czech Republic.