Sealing chipped cheap plates

I confess I am terrible about taking BEFORE pictures. Even when I take them I manage to lose them. I KNOW I took pictures of these plates they day I bought them, but they have slipped through my fingers.

These 19th century cake plates are ‘soft paste’ porcelain, which is basically a cheap porcelain, think paper plates. In my opinion these were disposable, they are lightweight, no hallmarks, the glaze is very uneven, and even rough in some places around the back edge. And that’s even BEFORE we factor in 150 years of wear and tear. There are a couple which have long edge cracks, and half have thumbnail chips around the edge, obviously one has a large cracked chip. But they made me smile….and they were cheap as chips, $12 for the 8 of them. I still have no idea when they were made or even WHY. They depict women at work, which doesn’t sound like party decorations…. I think PERHAPS, they were meant for girl’s tea set? I mean who else would think old pictures of women laboring were interesting, attractive or appropriate?

The 8 plates had various levels of browning. Where the glaze had cracks and fissures, the discoloration was pronounced, with the edge chips being VERY brown. I immediately put them into soak in a dishpan with a good dollop of Oxyclean stain spray, it’s just what I had at hand, I could have used generic powered oxygenated laundry detergent but it was in the basement. Over the next 3 days I changed the water a few times, and the browning faded away to a light yellowing on just the inner surface, and around the back. To be clever I put them outside in the sun to dry……within 10 minutes all the raw chipped areas were DARK BROWN. It was like watching a photo print develop…I found this photo sensitivity to be fascinating, albeit not helpful. I needed to re-bleach them and then seal the exposed porcelain after it has dried but before it starts to react with the light and atmosphere.

I tried hitting them with various clear coats, lacquer and epoxies, neither dried hard and thick enough, and wouldn’t adhere to the glaze that was already there, they just rolled off like dried glue. I went out to find something else, I figured some sort of epoxy or urethane product, but I came back with Rustoleum’s Triple Thick Glaze acrylic spray which is a specialty item I shouldn’t have even found in a shop. Holding the plates out of the window, I put on a primer coat around the edges, which dried pretty quickly. Unlike other type of painting I don’t have to worry too much about sanding and smoothing since the original glaze is rough uneven and imperfect, ideal for this sort of repair.

The acrylic dried hard and indeed surprisingly thick, I may put another good coat over both sides to seal all the tiny cracks and fissures from the air. None of this will effect their usefulness as cake plates. Since they will never be heated, it doesn’t matter what food I put on the plate. But it will be interesting to see if they ever turn brown again. I had tried many years ago to use a chlorine bleach to drive out the brown crazing, but as soon as it dried the brown would creep back under the glaze.