PSI - Issue 10

E. Tsetsekou et al. / Procedia Structural Integrity 10 (2018) 227–234 E. Tsetsekou et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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Table 1. Reversibility of adhesives with the use of solvents in a scale of 1-5. (1: easy and complete removal from the surface and 5: irreversible).

Reversibility of adhesives applied before and after ageing

Before ageing

After UV cycles

After RH-T cycles

Fir

Maple

Fir

Maple

Fir

Maple

Adhesives

1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

Casein Rabbit-skin glue Fish glue Paraloid B72 Vinavil

ΔΕ* of adhesives applied on fir and maple samples after ageing with UV

10 12 14 16 18

Fir Maple

0 2 4 6 8

ΔΕ*

Wood Fish glue Paraloid B72 Vinavil Rabbit glue Casein

Fig. 8. ΔΕ * of bare and glued wood surface of fir and maple samples following their ageing under Xenon Arc lamp.

4. Conclusions

Based on the results obtained, fish glue and Paraloid B72 created the strongest bonds both in maple and fir un-aged samples. All adhesives created stronger bonds in maple samples than fir, except casein. After ageing with UV, Paraloid B72 and fish glue still presented the highest maximum load at break for both species of wood. Ageing with RH-T cycles had greater impact in the adhesives' strength than UV; however still fish glue and Paraloid B72 performed well. The greatest wood failures were presented by rabbit-skin glue followed by fish glue. However all adhesives tested presented wood failures except casein. Regarding colour stability Paraloid B72 and Vinavil appear to be the most colour stable adhesives after UV ageing. Reversibility of the adhesives was not affected after UV ageing except for Vinavil's. In contrast RH and T cycles had a negative effect in the reversibility of all adhesives in both species of wood. Taking into account all the above, Paraloid B72 and fish glue demonstrated the best performance as conservation adhesives for dry wooden artifacts. However, repetition of some experiments using more than four replicas is con sidered necessary in order to obtain less variable results with lower standard deviation values. Further research is, also, required to investigate the impact of adhesives’ concentration to the type and degree of wood failures . Finally it is considered important to state that there are no good or bad materials in conservation but only suitable or not for a specific case.