Why is that glass so NASTY? by Jenny Creekmore

1933 Mills Novelty Roman Head Jackpot With Original Laminated Glass

When I was first learning how to repair and restore antique slot machines I asked Don “Why in the world is that glass so NASTY?”    I am referring to the various areas of the slot machine that utilize glass, such as the reel window, escalator and jackpot.  This can be seen in the slot machines manufactured during the 1930’s to 1950’s.

The glass may look very dirty and in most cases cannot be seen through.  It may look yellow or brown and could even have a flaking appearance.  No matter how many times it is cleaned externally, it will not come clean.  

1937 O.D. Jennings 4 Star Chief Reel Window Glass Obscured By Delamination

Don explained to me what happened to the glass and why this was occurring.  I was surprised by the answer and it is something we do get asked frequently.  

So here is the answer!

The glass used was an early form of laminated safety glass.  Over time, the early form of plastic used to make the laminated safety glass would deteriorate or break down leaving the nasty appearance described above.  Sometimes the fused glass can be separated and cleaned with lots and lots of elbow grease.  However, in most cases, the glass simply needs to be replaced and cannot be salvaged. 

We are only aware of one other form of safety glass being used during those times.  It is the jackpot wire glass used by Watling, which is prized by collectors today.

Original 1937 Watling Rol-A-Top Jackpot Wire Glass

I hope you find this bit of trivia to be as interesting as I do.
Jenny Creekmore