A moving company contacted me. They just relocated a client from the midwest to a small town in Vermont. One of the client's objects was damaged, an antique mirror with a gold-painted plaster frame. Part of the top of the frame - the eagle's head - was broken. Could I restore it?
Technically, it's a gilt plaster frame. Gilt is a thin coat of gold leaf or paint. In this case, the plaster is coated with both genuine gold paint and non-gold or 'gold-effects' paint. Gold paint does not tarnish while gold-effects paint contains particles that look like gold but will tarnish over time.
We agreed on a price and I soon received the mirror. I took pictures of the damage and began researching the internet for similar objects. I noticed that it had been repainted at least a couple times in certain places. This meant that the antique had been repaired before. Despite previous repairs the surface remained genuine gold paint. There were also many small chips in the plaster surface and one other section where plaster was missing. I decided to repair these as well at no extra charge.
My Internet search revealed similar objects which are not identical but helpful in recreating the missing plaster. It also revealed that mirrors of this type are quite valuable even in a restored state.
First step, cleaning. This is done with soft cotton balls lightly moistened with water. I removed dirt by very slowly and lightly dabbing the surface without allowing moisture into the cracks. Wiping might scrape the paint off.
Drilling and Pins
Next step, drill holes into the two broken sections. I glued tiny metal pins into these holes to strengthen the new plaster and make the repair as durable as possible. My work is guarantee so I don't want to repair this object again for free! The drilling process sometimes causes further damage by cracking the plaster, so I used the thinnest drill bit on a high-speed drill. Great care was taken to make the holes shallow and keep them away from the sides.
After letting the epoxy dry overnight, I moistened the existing original plaster with a brush and water. This allows more of a bond between the old plaster and the new. There are various latex and other mixes that make the two plaster materials bond better, but I feared that a chemical application of any kind might interact badly with the original plaster since I didn't know exactly what it was.
There are many kinds of plaster so I used the powder of the original plaster created by the drilling to give me a better idea of what the original plaster mix consisted of. The color also helps in this. If it was a high-end repair, the powder would be sent out for chemical analysis to match it exactIy. I settled on a tried and true product, Plaster of Paris.
The new plaster was mixed, applied, and allowed to completely dry for several days.
Next, the dried plaster was shaped to match the original. I used various types of fine sand paper from 220 to 600 grit.
After shaping, several coats of gesso were applied to seal the plaster and prime the surface for paint. The gesso is thick so I also use it to smooth the surface of the plaster by filling streaks and small holes. I sanded the gesso to more finely match the original surface texture.
Now the fun part. I mixed various shades of gold paint (14 and 24 karat) along with darker and lighter pigments to exactly match the original genuine gold surface as well as the non-gold streaks of tarnish and age.
Several coats were applied and each was followed by light sanding to match the texture of the original.
While I was at it, I repaired over three dozen tiny chips and scrapes. The project was finished in four weeks. The client was so satisfied that he's asked me to repair other pieces from his antiques and art collection.