Gluing archaeological wood

In this chapter, archaeological wood is defined as wood that, as a result of time, exposure, and possibly conservation-related treatments (e.g., consolidation or stabilization), may have gluing properties or limitations signif-... 

One might expect to encounter several types of archaeological wood gluing. For instance ... 

Thus, adhesives used in the gluing of archaeological wood will generally be limited to those that can, even in the long term, be unhardened (i.e., dissolved, softened, or weakened), and permit the joint to be disassembled. This limitation normally means adhesives that remain soluble in water, are organic solvents, or can be heat-softened at moderate temperatures. Further comments on specific adhesives are given later. 

The literature of archaeology and conservation seems to yield little in the way of systematic studies, information, recommendations, or experiences related to the gluing of archaeological wood. Individual experiences are referenced (e.g., 7, 9) and fundamental adhesion theory is presented in several conservation articles and book chapters (12, 16), but little is to be... 

PEG-Treated Wood. Wood treated with PEG will also have modified gluing properties, although, if properly redried, not as much so as heavily consolidated wood. The use of PEG as a dimensional stabilization treatment was developed in the 1950s (20) and it has been used on a limited scale since then. The utility of PEG treatment for waterlogged archaeological wood is now widely recognized, and it is quite possible that some of the wood so treated has been or will need to be glued. 

Decay spores are almost universally present. Given the presence of wood, suflScient moisture and air, a tolerable temperature, enough time, and the absence of substances toxic to the decay organism, decay will surely begin and proceed to the total destruction of the wood available. Therefore, there are few truly ancient or archaeological wooden artifacts, and the problems involved in gluing them may often be as much academic as real. 

Wood that has survived archaeological time and conditions will undoubtedly have gluing properties that are, in varying degrees, different from those of fresh unmodified wood. Bulk strength may have been reduced and fluid permeability and absorbency increased. Surfaces, in particular, may have strength and wettability that have been altered by aging. Treatment with consolidants and dimensional stabilizers may have been necessary, and this will often leave surface residues and reduce permeability and absorbency. 

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