A common problem with older pinball machines is raised inserts on the playfield.  Inserts are the colored opaque plastics that are lit up from underneath with lights.

There are a lot of theories on why the inserts pop up. I believe it is the result of the wood drying out and shrinking and then get humid and expanding again.  It heaves the inserts up and breaks the bond of the glue holding them in place.  I also believe it could be the heat of the lights underneath causing parts to expand.

I have come up with my own solution to fix this problem.  Previously people recommended heating the area up and then placing a block of wood over the top of the insert.  Then they would give the block of wood a good wack with a hammer and hope it did something.  I call this the Neanderthal Way.  It risks breaking the insert and scratching or damaging the surface of the playfield. It is also very hard to judge exactly how much force you are using.

My approach is the more sophisticated way.  I get out a big deep throated C clamp and two blocks of wood.  I then press the insert back down gradually. It is more controlled, less damaging and just plain smarter.  It is probably a little slower, but that is the price for perfection.

Catch the short video below of what it looked like and how it was lowered.