Stability

This is an update of a post I originally offered in March of 2018:

A while ago, I read an article in the New York Times on how artwork produced in the past seventy years was disintegrating rapidly. The deterioration was due to impermanent pigments, aging materials, and chemical conflicts between elements in a 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. There was an explosion of new pigments and media during the twentieth century. Plastics, acrylics, adhesives, fabrics could be added to art and have been. Regularly, I read about fading pigments, disintegrating substrates ( like paper, cardboard, or cloth), or adhesives failing. Little of the furor involves those who utilize wood as our main media. But let’s not get carried away with better than through sanctity. Woodworkers combine multiple materials too.

I create portraits of 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. Blanks are allowed to rest for a few weeks to ensure a stable construction. Then, when I get around to laying out the project and carving the boat or ship onto the cherry blank, I am sure it will not come apart. 

I may add bits of plastic, metals, bamboo, and other materials to represent equipment on board. 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 portrait. Potentially, through the years, my work faces the same issues as other artists face. 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. Then, oblivious to the possibility that these joins might fail after curing, I proceeded with carving right away. 

The early failure of one or two blanks alerted me that something was wrong;

• I checked the moisture content of the wood I use for the blanks, 
• I carefully laid out the blanks and constructed their alignment to allow 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 more robust 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 becomes “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 things like mast hoop portraits of vessels. Most marine varnishes have ultraviolet inhibitors that add their tint to a finish and 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 that 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. Still, as my technique developed, I began to use barrier coats between the colors and the varnish because not all problems showed up right away. A barrier can be as simple as shellac or something compounded and sold by the manufacturer of your pigments. If you create 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 the Liquitex brand, but you may prefer another. Established brands have websites that offer FAQs on their product. Remember, paint is not just one ingredient. It’s helpful to know about the pigments, the number of pigments binders, and the 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 others’ experiences. When in 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.