There are two different types of protective adhesive on pinball machines are they can be removed using several methods. The method you choose to use can depend on what type of protective adhesive is installed on the game. First, a bit of History ;
Contact is typically a 3M product that was used to cover school books in the 70's and 80's. The first time I saw contact on a machine was in the late 70's, on a Stern "Pinball" and "Memory Lane". Alll the playfield parts were removed, the contact was applied and then the parts re assembled. The contact covered the entire playfield and was usually cut around the posts. Sometimes, contact was applied is sections to high traffic areas. It was also retro fitted to EMs over time. Bally Solid States had factory mylar "half moons" packed in the game envelope around the time of Eight Ball. The operator installed these patches at their discretion. Contact can be bought and used on machines today, but now that mylar is readily available, no one should be using contact.
Mylar is thicker and stronger than contact. Adhesive is also much stronger. It appeared on factory games in the early 80's. The first game I saw it on was GTB Spirit. They are cut to fit each game and applied during production. DMD machines had factory sections applied in high traffic areas and around outholes and scoops. Mylar is available from many pinball parts suppliers either in the size of a full playfield, or in sections.
Removal - Based on my experiences
The most important step in removal is correctly identifying exactly what you are removing. If the game is an EM or early SS, then the chances are that it is Contact. It the game is a later SS or DMD, it would be mylar.
Mylar Removal - I've only used the hairdryer method on VERY deteriorated mylar and it came off very easily. I cleaned the residue with white spirits. I've never used the freeze spray method, mainly because I have not removed mylar from a DMD often.
Contact Removal - If you don't have patience, leave the contact alone. Keep the playfield clean and you should be fine ! Once you have committed to removing the contact, look for evidence of WHEN the contact was applied. Was it applied AFTER the game had substantial wear ? Can you see "ball swirls" or paint lifting UNDER the applied mylar ? Removing contact from an EM or SS with previous wear is risky as you may lift paint. If you use a liquid to "melt" the adhesive, it may seep into the cracks in the wood and lift the paint anyway. This is why I've NEVER used a chemical to "soften" the adhesive since a Playboy playfield that I almost destroyed. Some contact shrinks over time. These are harder to remove. Some lifts with little effort as the adhesive has hardened over time. I removed contact on a Solar Ride in 20 minutes, as the adhesive was completely useless. I removed contact on a Genie which took me over 20 hours. The ONLY method I use to remove contact is a hair dryer. This method uses heat to separate the adhesive from the contact by melting it. The adhesive is almost always left on the playfield and is easily removed with white Spirit, Shellite, Goo Gone or Goof Off. I tried DeSolvit once and it was ineffective on the playfield I used it on. This could be because the contact was different in quality and it stuck harder. I'd much rather leave the adhesive on the playfield, than to lift paint. I've had great success on almost all playfields.
Examples
Solar Ride -
http://aussiepinball.com/index.php?topic=1026.0Fathom (Page 2) -
http://aussiepinball.com/index.php?topic=6318.15Buccaneer -
http://aussiepinball.com/index.php?topic=6118.0Strikes and Spares - I decided the risks were too high to remove the Contact -
http://aussiepinball.com/index.php?topic=4878.0Canada Dry -
http://aussiepinball.com/index.php?topic=3836.0Skateball - Factory MYLAR - Don't mess with it if it is in great condition -
http://aussiepinball.com/index.php?topic=1987.0Sinbad (Page 3) -
http://aussiepinball.com/index.php?topic=225.30Genie (one of three) - Contact was in great condition, so I trimmed it -
http://aussiepinball.com/index.php?topic=2614.0Galaxy -
http://aussiepinball.com/index.php?topic=1256.0All games that had the contact removed used the hair spray method. The only time I didn't used the hair dryer method, I stuffed it up completely and sent the playfield to Gavin for repair ;
Playboy (first picture only) -
http://aussiepinball.com/index.php?topic=1103.0My experience is with EMs and SS machines with contact applied. I only use the hair dryer method.
