An interior designer recently asked me to gild a mirror frame. The frame was brass, and he wanted a silver leafed frame instead. I suggested switching the leaf to aluminum because silver tarnishes in unpredictable ways, even after varnishing. The frame would look like silver leaf, without the headaches. He agreed, and we were good to go.
Here’s the original mirror frame. The mirror was 33 inches high and 22 inches wide (84 cm x 56 cm). My cat, Little Roo, couldn’t resist investigating.
Step One: The Prep
In any painting or gilding project, prep is your friend. The better your prep, the less clean up you’ll have to do when you’re done, and the quicker the job will go. I taped off the mirror next to the frame using blue low-tack painter’s tape to protect it. The mirror was raised up on four paint cans to bring it off the table, which allowed access to the sides of the frame. The table was protected with a drop cloth.
Step Two: The Size
Gilding begins with sizing. Size is an oil- or water-based type of glue specifically made for gilding. In this case, I used slow-set oil size, which levels out as it dries so you don’t see brush marks. Gilding is usually done over a painted surface. I crossed my fingers that the size would stick to the brass. Luckily, it did.
I mixed the size about 5:1 with mineral spirits. This sped up the drying time of the size, which is usually about 10 hours. Thinned out, it dried to the correct tack in about an hour. I applied it with a half-inch wide natural bristle brush, sizing 5-inch sections at a time, gently blended the size out to the edges and brushed back and forth a few times to blend the last section into the next. I wanted an even coat; no pooling, no missed spots. The size is colorless, so it’s hard to see where it is. It pays to work slowly and to use a light’s reflection to see where you’ve been. Below, you can’t tell what has been sized and what hasn’t.
Step Three: The Tack
The size has to dry to a specific tackiness before gilding can begin. Too wet and the metal leaf won’t dry; too dry and the metal leaf won’t stick. The correct tack is found at the squeak: if you gently drag one of your knuckles along the surface, a gentle squeak will be heard. Too wet and your knuckle gets stuck and mars the surface; too dry and there’s no squeak, although there’s a window of at least an hour when the squeak is right. So don’t go out and start running errands! Stand by, set a timer and wait for the squeak.
Step Four: The Gilding
Luckily, I had a leftover roll of aluminum leaf to work with, which saved the hassle of buying a small amount of leaf. I like to work with rolls, which have individual sheets of leaf laid next to one another, overlapping by 1/8 inch. On the frame, it will look like each leaf has been applied individually, but by using the roll, the process is speeded up. I gilded one side of the frame at a time, cutting the appropriate length of leaf off the roll.
To apply the leaf, I used a soft brush to gently push it to the surface and stuck it down through the backing paper. It’s important to remember that the oil size below is still wet, and therefore the leaf is now wet and is delicate, so it has to be treated gently. Also, try to avoid touching the leaf; you may leave finger prints. Any cracks or missed spots were filled with little pieces of leaf until the surface was completely covered. Gilding makes a real mess; tiny specks of leaf drift to every corner of the room.
Step Five: The Patch
Somehow, I managed to miss a spot when sizing. No problem, I just applied more size, let it dry for an hour, did the squeak test and applied more leaf.
Step Six: The General Cleanup
Since the surface was delicate, only a general clean up could take place. I removed the big hanging pieces of leaf and gently brushed off the bigger flakes.
No pressure and no rough handling at this point. The size has to dry overnight before the leaf can be thoroughly cleaned. There’s still a lot of extra leaf on the frame.
Step Seven: The Final Cleanup
The frame has dried overnight and it’s time for the real cleaning. Using soft cheesecloth and a soft brush, I wiped and brushed the surface until all of the remaining bits and pieces of leaf fell away.
Although the leaf was now properly adhered, I didn’t want to scratch it, so I still handled everything with care. Once I was done, I took off the tape and cleaned up the inner edge, then taped the mirror again for glazing.
Step Eight: The Glaze
The designer wanted a soft aging glaze to cut down the brightness of the aluminum, which is glaringly reflective when fresh, but he didn’t want the frame to look dirty. I mixed up a glaze using Windsor & Newton’s Liquin Original, which is an oil medium and the only medium I’ve found that is transparent enough to use as a giaze over gilding. I added in a blob of raw umber from a bottle of universal tint, mixed it up and the glazing began.
The color looked quite dark when mixed, but once applied and manipulated, it was a sheer, light wash of color. I brushed it on with a one-inch wide chip brush, then pounced the surface with cheesecloth, taking most of the glaze off again. Below, the vertical edge is glazed while the horizontal one isn’t. You can see the warmth added by glazing in this color. The glaze gave depth to the frame’s surface without calling attention to itself and reduced the aluminum’s glare.
Step Nine: The Final Product
The mirror dried overnight again, the tape came off, and voila! A new frame. Total time for the whole process was about six hours. With the glaze, the look of the leaf became softer and it seemed to glow instead of shine.
Here’s a comparison of the original brass, before glazing, and after glazing. I love these jobs! it’s such fun to transform a piece in this way.