Tonight, I finished off cleaning the lower left quadrant of the playfield. My hands are sore from all the scrubbing.
Pictured on the left is the area around the flipper prior to the cleaning. On the right is the same area after a thorough cleaning.
Quite a difference. Next up is the upper left portion of the playfield. This includes the ferris wheel and a lot of hidden lamps that have been burned out for ages.
Daniel Jalkut commented It’s amazing how dirty something sealed in glass can get! I guess most of that grime is probably originated from within the machine itself?
A lot of the dirt is sourced from the machine itself. If you look at the high resolution original of the image at left, you can see just how grimy that (originally) white piece of plastic has become.
That particular bit of grime is most likely sourced mostly from the switch immediately above it. It is the “end of stroke” switch on the flipper and Cyclone’s EOS switches turn off a relatively high voltage. End result; sparks and soot. Of course, replacing the white plastic bit — the through-the-playfield pawl through which the flipper’s metal pivot passes — is not as trivial as unscrewing the three screws. There are nuts on the back. So, to do so requires taking the entire flipper mechanism off the back of the playfield.
So, a lot of the grime in such a machine is just carbon from all of the various random switches making/breaking contact. However, the machine is far from sealed. It will pull whatever particulate matter into the machine. That combined with the vast number of tiny ozone generators means that dust, smoke, and other grime quickly becomes electrical charged and immediately sticks to something nearby.
The worst is cigarette smoke. It builds up to the point of “drifting”. I’m not kidding. Nasty, nasty, stuff. Will kill a machine in short order. Once a machine is removed from a smoky environment, it takes years before the last of the stench is gone.
Another source of grime is the cleaning process. These are before/after shots of cleaning underneath a metal arch that had likely never been pulled off of the playfield since the machine was manufactured. Frankly, I have no idea where that gunk comes from. It is largely dirt but has a definite sticky goo quality to it. It is likely the product of improper cleaning over the years. Or from cleaning that involved liquids that ran down and got stuck underneath that piece of metal.