I received a replacement playfield from Stern, so I decided to fix my bubbling playfield. I didn't bother ordering an iron as I found a ghetto way of creating my own. I used a cheesy little measuring cup as my metal and heated it with a heat gun. I heated it up to the point that I could barely not touch it with a bare finger. That was the minimum temp that would flatten the clear.
Here is the cheesy tool (filled with paper towel so I could push down on it):
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Here is a before and after:
Before:
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After:
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I did about 6-8 different bubbles with this method. The only negative effects are that the circle of the "iron" left a smoother circle that can only be seen in the most perfect lighting, and this will go away in time, and that the bubble sometimes leaves behind a small line where it was unbound from the PF.
Notice the circular line around the far hole:
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None of this is noticable with plastic washers down. I put on washers with an inner rim to allow for flex, which will lessen pressure to the PF:
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