Not too long ago I read an article in the New York Times on how artwork produced in the past seventy years or so was disintegrating at a rapid pace. The deterioration was due to impermanent pigments, aging materials, and chemical conflicts between elements in mixed media artwork. Some things were never meant to last forever, and others were never intended to be together in art.
The issues were not only with modern works, but the majority were. During the twentieth century, there was an explosion of new pigments and media. Plastics, acrylics, adhesives, fabrics could be added to art and have been. Almost weekly I read about fading pigment, disintegrating substrates ( like paper, cardboard or cloth) or adhesives failing. Little of the furor involves those of us that utilize wood as our main media. But let’s not get carried away with better than though sanctity. Woodworkers combine multiple materials too.
I create portraits of peoples ships and boats, and yes, the major media is wood. But, it gets complicated. Wide planks are expensive, hard to find and due to wood movement and radial cracking not so great a basis for carving a portrait. So, I construct blanks from multiple pieces of cherry to get the size I need for a portrait. I join individual wood panels with adhesives, and the blank left to rest for a week or two to ensure that the construct is stable. Eventually, I get around to laying out the project and carving the boat or ship onto the cherry blank. To this base carving, I may add bits of plastic, metals, bamboo and other materials that represent equipment on the boat. Other adhesives hold those pieces to the carved portrait. After this is complete, we can add various pigments, carrier solutions, varnishes, and shellacs used to finish the portrayal. Potentially, throughout the years, my work faces the same issues as those faced by other artists. Most of my portrait work is younger than thirty years. There is plenty of time for trouble to catch up with me; will that super glue eventually react with that varnish?
The worst issues I’ve had have been with adhesives and varnishes. Early on I used marine epoxies to glue up the blanks I use for carving. Utterly oblivious to the possibility that these joins might fail after curing I proceded with carving. The early failure of one or two blanks alerted me to the fact that something was wrong. I take care to check the moisture content of the wood I use for the blanks, I carefully lay out the blanks, and construct their alignment to allow for seasonal change. So, I didn’t think it was a matter of simple wood movement. The failures were along the segment lines of the blanks. A well-made glue line along the grain should generally be stronger than the surrounding wood. You usually want a bit of the glue to squeeze out of the joint as you clamp it, but if too much glue comes out the joint is “starved” because not enough is left in the joint to create a strong bond. Using the marine epoxy too much glue was coming out. But, it’s not apparent until a joint fails. I solved this by switching adhesives until I found what I wanted. None of the portraits are in the wet, although their surfaces might get damp so, an adhesive like a carpenter’s yellow glue is what I wound up using. It’s sturdy, resistant to moisture, leaves no visible glue line, and has a long history of use.
But, trouble lurks all over the portrait – literally. I need to use marine varnishes to finish items that would go on to boats ( Quarter boards billet heads and transom eagles) but, I can’t use those finishes on items like mast hoop portraits of vessels. Most marine varnishes have ultraviolet inhibitors that add their tint to a finish and will change the color of painted objects. Silly me, I had to learn this lesson through experience.
As part of the gallery connected with this post, I’ve included an early boat portrait which had a starved glue line and discoloration caused by varnish UV protection. It’s painful to fess up to your errors in judgment, but it is a learning process, and I include a shot of a similar portrait completed with a better approach.
Next, on the list of potential bad boys are pigments. I do not like oil paints; I prefer acrylic. I’ve never had a problem with incompatibility between thoroughly dry acrylic paints and varnish, but as my technique developed, I began to use barrier coats between the colors and the varnish because not all problems show up right away. A barrier can be as simple as shellac or something compounded and sold by the manufacturer of your pigments. If you are creating a commission for a client, adding a barrier is a worthwhile step.
A friend who is a painter spent a good part of one evening convincing me that good quality pigments were not a luxury. Please do not use “craft” paints and expect something that has permanently vibrant color and that is chemically stable. I prefer Liquitex brand, but you may prefer another. Established brands have websites which offer FAQ on their product. Remember paint is not just one ingredient. It’s helpful to know about the pigments, amount of pigments binders and carrier medium involved. If it affects the long term color fidelity of your project or its stability, you want to know.
I do rarely use styrene or other plastics without problems. I have used metal wire, and small castings. I can’t remember using paper or fabric to date on any project. “To date” I’ve had no issues; please remember that ‘to date” part of things. I keep my eyes open to what others experience, and my best advice is to be proactive, use the internet to search out other’s experiences. When is doubt remember two of my maxims! KISS – Keep it simple stupid. And, the seven P’s – proper prior planning prevents piss poor performance. With luck and forethought, we’ll avoid becoming some restorer’s headache. Oh, and one more truism which also very “impactful” for our topic – your favorite search engine is your friend. There is a wealth of data out there for you to investigate.