|Woodworking can be a science project|
Working at the right temperature is critical to virtually every aspect of film formation and manipulation. Applying a solvent release coating (cellulose nitrate, shellac, etc.) and leaving it in the sun can result in disaster as solvent bubbles form in the curing film. Who knew that the classical gas laws we learned in ninth-grade chemistry (especially Boyle’s Law) had a critical role to play for our work?
Materials science is an amalgam discipline that concerns itself with the physical nature of materials: their creation, properties, and manipulation. In essence, it is the melting together of all the concepts of chemistry and physics together into one untidy whole. If I had to do it all over again, I would have probably majored in materials science in college, rather than chemistry, art and art history. Materials science is just plain fun to me.
Here are some of the considerations blended into the world of materials science:
Synthesis includes formulation, physical chemistry, configuration, and a thousand other considerations when designing and creating a coating material and all the portions of the system in which it might be used.
Rheology is, strictly speaking, the study of material flow, but, practically, it is defined in terms integral to the function and performance of finishing materials — hardness, flexibility, brittleness and toughness. This goes not just for film-forming materials, but also adhesives, fillers and any other part of the composite structure.
Appearance is such a complicated phenomenon with materials science that it overlaps with every other science discipline in this list. Why? Because the elements of appearance include: lighting color and source; the “observer”; color (which is itself a compilation of discreet components called hue, chroma, and shade); transparency; texture; gloss; and “colorant molecular architecture”, e.g. natural plant dyes vs. synthetic directional pigments. You have just described the elements of achieving any particular finish, especially the matching of an existing one.
The world of biology is a far-flung one, but there is a lot of it in wood finishing in the guise of deterioration, physiology, and agriculture.
A lot of deterioration is biological in nature and driven by the environmental processes necessary for life. Rot? Mold is really fungal activity, so count in mycology. Ditto mildew and related staining. Insect infestation? Make a check mark for entomology. Rodent damage? Mammalogy.
Visual perception is a fundamental physiological phenomenon. The individual components are so numerous it is nearly impossible to create a concise snapshot. In just the eye itself, there are issues of color acuity or color blindness, lens transparency or coloration, retinal condition, and how good is your cornea. Check ophthalmology.
How about the hand skills required to manipulate materials skillfully? Enter kinesiology, the study of human motion.
And what about the “natural” resins we use widely, things like shellac, damar, copal, colophony, etc. They are all agricultural products, with all the vagaries that implies. Some are from the insect world (shellac) most are from the realm of tree exudates.
And then we move on to the effects of all the chemicals we use on our bodies. All chemicals are problematic under the right (or wrong) conditions; any chemical can and will kill us. If we are using poisons, we’d better be functionally well-versed in toxicology (the dose makes the poison). Many of the tree-based resins are polyterpenoids, which are among the most virulent allergens known. Hello, you’ve just been introduced to immunology.
Anyone who does what we do skillfully is a scientific scholar of the highest repute, even if they don’t know it.
Don Williams has been a furniture finisher for more than 35 years. He is Senior Furniture Conservator at the Smithsonian Museum Conservation Institute.