(Topic ID: 119065)

What to do about cupped inserts on Grand Prix

By textrivers

4 years ago

Topic Stats

  • 10 posts
  • 5 Pinsiders participating
  • Latest reply 4 years ago by Mikala
  • No one calls this topic a favorite


Linked Games

Topic poll

“What should I do about cupped inserts on Grand Prix?”

  • Pop them out, heat them, press them flat 2 votes
  • Fill them with superglue 0 votes
  • Replace them with new ones 1 vote
  • Don't worry about them, focus on relationships with loved ones and solutions to societal problems 7 votes

(10 votes)

#1 4 years ago

What should I do about the cupped inserts on my Williams Grand Prix? They're all cupped, and cupped badly enough to affect play at least once per game. Also, there are a LOT of inserts on this game -- I believe I counted 55. A number of them seem to have been screen-printed over, meaning that the black encircling them on the playfield continues onto the insert itself.

I don't want to do any automotive clear-coating. The playfield isn't in the shape to justify it, plus I am not interested in this practice in general. This game will never be a beauty queen -- I just want it to play right.

What do you think? What's the best method here? Any solutions I missed in the poll above?

#2 4 years ago
Quoted from textrivers:

Any solutions I missed in the poll above

You can buy (or make) removable mylar repair disks.... I have some on order to replace the homemade versions I was using on 1 of my games. Basically concentrically larger circles build up the cupped insert. Good solution for a playfield that isn't worth a huge repair.


#3 4 years ago

That's perfect, I did not know about that solution. It appeals not only to my conservator's mindset, but also to my laziness! Thanks for saying something!

Edit: Now that I'm looking at them, it could get pricey to do 55 inserts this way. How did you do your homemade version? Would you do it again, differently? I guess not if you're ordering them.

#4 4 years ago

Hi textrivers, I'm the owner of oldpinballs.com and maker of the playfield insert repair discs here in Australia, and thanks Wickerman for the recommendation.

I designed these discs for one of my own machines many years ago and simply sell to help others in the hobby. All the adhesive discs are machine cut on a wide format cutter which I own.

textrivers if you send me a PM we can discuss a custom design and cut for the multiple inserts on you title.

#5 4 years ago

You can just fill them with clearcoat.

The clear reinforces them from further cupping and makes the playfield dead level.


#6 4 years ago

Hey oldpins, thanks for saying hey! I'll send you a PM.

#7 4 years ago

Are you using the right description term here? Are the inserts really cupped, or just sunk? I understand cupped inserts are common in other makers EM's of this era, but I have rarely see a 70's Williams with cupped inserts. Sunken, yes, all of the time.

If this is the case, just remove the inserts with a heat gun or blow dryer and then reset with superglue gel and press flat. It will not take you too long to do and the results are very acceptable.

Watch this series of videos on youtube. 4 parts. I have had great success using this

#8 4 years ago

I would like to add, I do not recommend filling with Polycrylic, it is my understanding that you have to wait almost 3 months for a true cure, then sand down the inserts flat. A lot of work that you already said your not ready for.

In these video's, this guy sands down the inserts, that's too much work and trouble and defaces your inserts. Just Novus 2 then 1 then inserts to a nice bright shine. If you do not want to go through all of the videos, just watch parts 1 and 4.

Here are the rest of the videos.

#9 4 years ago
Quoted from Mikala:

Are you using the right description term here? Are the inserts really cupped, or just sunk?

So "cupped" would mean concave, and "sunk" would mean flat but settled below the level of the playfield, correct? If so, they're definitely cupped. Thanks for the video links!

#10 4 years ago

Yes, you have the correct understanding. GL

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