Mirror desilvering to replicate original graphics
Posted: Sun Apr 03, 2016 2:28 pm
Thought this might be of interest to somebody about how I made a replacement mirrored glass on the cheap with simple tools. The glass on this late 30's French Roulette called Grand Prix was badly damaged. The paper artwork had buckled over time and someone reglued and later when it re-buckled that pulled the silvering off. The owner wasn't happy with how it looked but had invested far too much into the machine before I ever saw it so I had to keep costs down. The hand drawn paper artwork was badly faded and we decided that should be brightened along with much needed rebuilding of cabinet which had been broken apart and badly rebuilt. On removal from the machine the glass was very poorly cut in the first place with chipping around the edge. The cost to have a local glass company mask and resilver the mirror was prohibitive, plus I thought it would end up looking too new for the machine. So after a little thought decided I could easily make the replacement from scratch using vintage mirror glass with small chips and stains. I've never cut circles before and the cost of a special compass cutter was high for just one job right now, so made this one from scrap. (The lock/release suction cup is from an old ice crusher base, which was used to stop it sliding around as you turned the handle.) This first time circle cutting was a test and while not perfect was far better then the original glass so decided to use it. Then I marked out on the back the areas of silver that needed to be removed and once happy lightly scribed through the paint on the back with a paper cutting compass. Then carefully scraped off the paint with a scalpel that I de-sharpened slightly. Though since this was a good quality mirror there was also a layer of copper on top of the silver so not easy to scratch the glass anyway. Then a quick burnish with fine #00 grade steel wool to remove any tiny spots of paint. A quick tip, the next finer steel wool is #000 but costs 3 x the price over here for very little difference! While the #00 sells for the same price as all the other thicker grades. I use it all the time so keep in stock #3 - coarse, #1 - medium, #00 - fine. I then went outside to remove the copper and silver layers, wiping it off with a rag and a little Ferric Chloride, commonly used to etch circuit boards. The acid had no effect on the remaining paint which worked as a resist. I forgot to photograph this after completion but my buddy was very excited to add it to his collection and at some time soon I'll be over there to get some pics of it.