This was a really beautiful antique mirror with beveled glass that I picked up at a Flea Market. I think I paid 10$ for it. The mirror was in perfect shape, but the frame had a few big chips in the curved veneer. I assume that this mirror is from around 1880, but it could be slightly older or newer. Definitely older than 1900.
For probably close to a year it's been patiently sitting and waiting to be repaired. I'm not even sure where I want to hang it yet, but since I've been doing a LOT of veneer patching on clocks lately, I decided to do the repair while I had fresh hide glue on hand.
All 4 corners had chips, but the real issues were with this one bottom corner. The other corners had very tiny chips (I didn't photograph them, they were only about 1/8" wide).
Because of how this corner was broken, I would either need to make two striped patches (which would be tricky and possibly ugly as a repair), or remove the entire corner section, and install a larger patch. This is what I did. With the wood veneer that I removed, I was able to patch all the other 3 corners, so those repairs ended up being virtually invisible.
Corner section removed. The mesh is something new to me. I'm not sure exactly what it was for, but it seems original and I left it there. Part of the veneer was loose past where I cut it, so hide glue was brushed/pushed under there.
The wood was a bit odd. It looks a lot like walnut, but I was fairly sure it was actually mahogany, so I used mahogany for the patch. The wood had to be pre-curved around a form (you just wet the veneer in hot water, clamp it around a curve that is tighter/smaller than what you need, and leave it to fully dry). Once it was glued down (using hide glue and painter's tape as clamps) the edges were trimmed, sanded, and the repairs were stained as needed.
The finish on the mirror was kind of dry and flaky, so I scrubbed down the finish lightly with steel wool and alcohol, and then I added a few thin coats of shellac over the repairs and then over the whole frame. This was then buffed down and wax polished with steel wool (#0000) and dark tinted wax.
The colour match on the patch is not a 100% perfect match because the old veneer was somewhat sun bleached. It blends in fairly well, and it's only a simple mirror, so not a museum piece.
All these techniques can be used to repair clock cases.