Really fuming, now!
I recently acquired a 1920s etching by the English artist George Marples. With the subject matter (an old mill) and the time period, I decided an Arts & Crafts style frame would be appropriate. I got a nicely rayed piece of QSWO out of my stock and proceeded to mill and joint. I didn’t want to do something too elaborate that would take away focus from the art, so I didn’t try to do a Green & Green style frame, settling for a simple lapped joint frame with ebony plugs. (Well, African Blackwood, really. Tomatoes, tomahtoes.)
When it came time to finish, I found that I didn’t have any Walnut Danish oil on hand (my normal go to A&C finish), and the closest available was an hour away. So, not having time to make the trip, I read up on the technique of fuming oak with ammonia, a period appropriate method. The ammonia fumes react with the tannin in the oak, causing it to darken. Traditionally this is done with aqueous ammonia, a very strong concentration that is highly toxic, and of limited availability. Not something I really wanted to mess with, not having the necessary safety equipment. But, some people have been experimenting, lately, with using household cleaning ammonia, janitorial strength preferred. Stopping by the local hardware store, I found some “Extra Strength Ammonia.” Very generic, no strength concentration listed, and cheap. I decided to give it a go.
I set up a tent outside using a plastic painting tarp and some loose boards and bricks. With the wind to my back, I set the frame inside with a tray that I filled about halfway with the ammonia. Honestly, I didn’t even get a whiff of the ammonia smell, so I was wondering just how strong it really was. The big difference between household ammonia and the stronger stuff is how long it needs to be exposed. So, I left the frame in the tent for a couple of days, checking it periodically.
After the two days I untented to check, and possibly refresh the ammonia. The bright sun was deceptive, but it was decidedly darker, although grey rather than brown (which I was expecting). It had worked! (assuming the finish browns it as advertised.)
I applied 4 coats of my favorite satin oil/varnish, and it immediately showed its true colors, a rich nutty brown. Now I could really see the benefits to fuming rather than using stains, dyes, glazes, etc. to imitate the fumed look. Some of the “fake” methods do bring out the medullary rays better, BUT, they lock in the color, In the fumed oak, the rays have a chatoyance that is lost under stains and dyes. There is a depth to them and, depending on the angle of viewing, they change from a light brown ray against the darker field to a dark brown ray.
That’s the magic of fuming. Its not just the color.
To finish up I glued in the polished plugs, matted my etching and used a point driver to secure the mat, art, backer and glass in the frame. Ready for hanging.
Even though fuming a large piece would be more of a pain, building a big enough tent, I don’t know if I can ever go back to a stained A&C finish. That’s got me fuming!
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