Flattening Playfield Light Shields (Plastics)
 by Chris Hibler

Many techniques have been offered for bringing your playfield plastics back to their original flat form on RGP.

I've used the "camp stove method" which works pretty good but the risk of "bubbling" irreplaceable plastics is too high.

I've never used the "oven method" as I just don't like the idea of putting irreplaceable plastics in an oven. Sure, it's a controlled environment, but I think the option detailed below works better as it's impossible to leave the plastics in the "oven" too long.

In St. Louis, the hot summers are perfect for flattening plastics. This procedure is simple and completely fool-proof. It is nearly impossible to ruin your plastics using this method, the one caveat being extremely warped, brittle plastics (butyrates), and I don't know how anyone would deal with those anyway.

Procedure

  1. Remove the playfield plastics and clean with Novus 1 or your choice of cleaner. I like Novus 1 as it's very mild on plastics.

  2. Use Windex to clean two sheets of playfield glass. Let the Windex evaporate completely.

  3. Sandwich the plastics between the two sheets of glass in a hot place. If the plastics are extremely warped, don't lay the top sheet of glass down all at once. Rest the edge of the glass on something that will allow the plastics to heat up for an hour or so, then lay the top sheet down all the way. Note: I've never had to do this but your mileage may vary.

Top View: Here I chose my truck bed in direct sunlight. The black bed liner increases the heat.
These plastics are from Gottlieb's 1975 Fast Draw/Quick Draw

Side View: Here's a side shot of the setup. The yellow arrows point to the two sheets of glass.
You can see that the warped plastics lift the top sheet up some.
As the plastics soften, the top sheet will gradually sink.

  1. Wait 2 or 3 hours. What I like most about this method is that the timing is not critical. I usually set the plastics out some time during the day then wait for sundown to bring them in. It's impossible to "over cook" them.

  2. Carefully remove and allow to dry in a cooler location.

  3. Poor your favorite cold beverage and marvel at your genious.

For additional information, you can contact me at chibler@charter.net.
Or, ask Team-EM on RGP.