It's very hard to walk away from a beautiful old mirror.....especially when carrying it home doesn't require packing and shipping like when I was living in the US. A reader asked me about repairing a gilded piece and while I am far from being an artisan of this nature, I thought I would share a project I am working on.
Antique mercury mirrors are heavy.....very heavy. Old wooden boards often back these pieces to provide the stability for the thick glass and this combination equals significant weight.
This particular piece had the original mirrors I love, the backing I wanted and the type of design I was looking for. The problem was that the entire top section of the oval mirror was missing.
I've had this piece for several years but I finally decided to test out a way to repair the decorative surrounding.
There are many, many choices for repairing old sections and just as many products that can be used to do so. They range from creating a mold and casting it in plaster to doing what I did and free handing it.
I chose to use a thick mastic putty for the base layer that would be attached directly to the mirror. I knew the process would be slow because the mastic has to completely dry to set up and become strong. The wait was worth it to me because the trade off was providing the beautiful beveled mirror the stability I wanted.
After the first layer dried for a day, I began layering with a softer mastic (that comes in a tube) allowing it to dry completely between coats. It has a workable (although slightly sticky) consistency that can be spread or pushed on (as I did) and then further shaped as is begins to dry.
During this period the form can be shaped by pressing gently against it as you would with a soft clay. You will need to stay close to the piece and check that the form doesn't start to drop the desired shape. The thicker the layer you apply, the more likely that you will need to reshape it as it dries.
It have applied 3 layers to the mirror including the base and still need to lightly sand it for smoothness. Once that I am satisfied with the general shape, a thin layer of plaster of Paris will be applied and detail (as you can see it the above photo) can be added. You can also see where mastic was added to stabilize some cracks and to reform a broken leaf.
I haven't decided if I will paint it or leave the last layer of plaster exposed, but that will depend on how it looks after the sanding.
Repairing the gilding itself is more complicated on this piece because it is a combination of both gold and silver and I am not willing to tackle that. However, applying gold to the leaves and central medallion isn't a complicated process.....matching the color that has developed over time is.
All old gilding has a painted undercoat. It was done to mask imperfections in the process as well as to change the tone of the gilding. Golden pieces have a yellow or deep red base. Yellow was the standard used to hide flaws, red to give a richer tone to the gold. Silver pieces have either a blue or black undercoat, with blue used to provide richness to the silver.
Once the chosen undercoat paint was dry, a sizing glue was applied. As soon as the glue became tacky, a thin leaf or sheet of the gilding was gently laid over it and then burnished on to the surface.
The types of paint, glue and burnishing tools are what make matching old gilding so tricky. There are companies that specialize in producing products in historical ways, and many believe it is impossible to recreate old gilding without using them. However, unless you have practice in gilding, burnishing with a bone may be a tricky way to start off.
Like anything, the more you research and read about gilding and the historical methods used in producing it, the more you will be prepared to work with your treasured pieces.