|Restoring Playfields with Magic Erasers - The Tests|
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Clean's Magic Erasers for cleaning pinball machine playfields was first
mentioned on the rec.games.pinball newsgroup in March of 2004. The
early reports were mixed - some people were impressed with their
performance, others said they did little or nothing. So I was
determined to try them out for myself, and this page describes the results
of my tests.
I did two separate tests. First I used a Magic Eraser to clean a Close Encounters pinball machine playfield to see how well it would do removing dirt and swirl marks. This got me curious as to how abrasive the Magic Eraser pads really are, and if they work differently than wet/dry sandpaper. So I took a very worn, scrap playfield (a Bally Playboy that will be getting an overlay), marked off four separate areas and compared the Magic Eraser to three different grits of wet/dry sandpaper (400, 800 and 1500).
For those of you not reading the entire page, here are my conclusions.
Details of these tests are below.
Cleaning a Close Encounters
I used my first Magic Eraser to clean a Gottlieb Close Encounters that was very dirty and had moderate ball swirling. I first cleaned off the major crud with Novus 2 and then got to work with the Magic Eraser, wetted with 92% isopropyl alcohol.
Easily 90% of the swirl marks were removed or cleaned out, and I probably could have done better if I kept going. But I didn't want to wear through the topcoat and although I used up an entire eraser on the playfield, I had no wear-through spots. Here are some thoughts:
Magic Erasers are simply great for restoring old playfields. Just keep in mind that unlike Novus 2, you can remove significant amounts of material with these things. This serious abrasion will also lift any hanging pieces, and after the crud has been cleaned out of the chips and cracks, it would be wise to do something to keep the dirt out. I don't think polishing with Novus 2 and/or any kind of wax would be sufficient, although it may look great over the shot term.
And now for the pictures. You can see from the close-ups how well the Magic Eraser does cleaning a fairly dirty playfield. It also took off enough of the oxidized lacquer topcoat to make the playfield noticeably brighter. The before and after photographs were taken under similar lighting conditions and with the same camera (a 5 megapixel Nikon Coolpix 5000). Some of the close-ups show that the cracks in the playfield topcoat are still substantially there, but much of the dirt in the cracks has been removed by the Magic Eraser.
Click on any of the pictures above to open a larger view in a new window.
How Abrasive are Magic Erasers?
After that first successful experiment, I was curious just how abrasive these cleaning pads really are. Some other users had worn through to the artwork while trying them out, and others said that they had no effect at all. So far, they were "just right" since they had removed most of the dirt and dreaded swirl marks, without any collateral damage at all.
It was clear that the Magic Erasers were removing something, since the liquid residue was a different color than the pad (white) or the alcohol (clear). Lacquered playfields have a fairly thick layer of lacquer over the artwork layer, which is a very thin layer of silk screened inks. When you sand or polish a playfield, you are usually just affecting the top layer of clear. In fact, the layer of artwork is so thin, that if it is ever exposed, it is extremely easy to damage. There is usually a base layer of white ink, so the first sign of wear-through of the ink layer is a lightening of the color to white. Beyond that, bare wood will be exposed.
Swirl marks are a very common flaw in older playfields. They are caused by microscopic cracks in the top coat that then become filled with black dirt. These cracks are usually circular arcs or they run along the grain of the wood. Or both. Swirl marks have defaced many a playfield, so anything that helps reduce their deleterious effects would be quite welcomed. The problem with most swirl marks is that the cracks usually run all the way down through the top clear layer down to the ink. So if a simple abrasive is used to sand off the clear, the swirl marks will disappear only when the entire top coat has been sanded off. And since this is a practical impossibility, you're left with some combination of swirl marks left behind and artwork damage.
So the purpose of this test was twofold. First, to get an idea of how quickly a Magic Eraser removed a lacquer topcoat compared to regular wet/dry sandpaper. Second, to verify what I noticed when cleaning the Close Encounters playfield: that they remove dirt from swirl mark cracks, without necessarily removing the cracks themselves. I also wanted an idea of what happens if you just go too far with a Magic Eraser, so that I could avoid doing that in the future.
The playfield that I chose for this experiment was a pretty wasted Bally Playboy. There were multiple spots worn through to the wood, plenty of dirt and it was covered with swirl marks. I plan on installing an overlay on this playfield, so a little more damage wouldn't matter at all.
Now I split the center of the playfield into four areas. The bottom right section would get the Magic Eraser, The other three areas got different grits of wet/dry sandpaper: 400 grit for the top right, 800 grit for the bottom left, and 1500 grit for the top left. Each area was rubbed wet with isopropyl alcohol for approximately 90 seconds and the results were evaluated. No further sanding was done after an area started to wear through. The pictures below were taken without a flash, so the white spots in the artwork are wear-through, not glare from a flash.
First Pass - 90 seconds
Second Pass - 3 Minutes
Third Pass - 4.5 Minutes
Final Pass - 6 Minutes
The pictures below show the effectiveness of swirl mark removal up to the point of total topcoat removal.
It's clear that the Magic Eraser removes swirl marks much more effectively than wet/dry sandpaper, and its abrasiveness is similar to 1500 grit wet/dry sandpaper. This test playfield was heavily worn to begin with, so there wasn't much of the topcoat there from the outset. Even with the worn topcoat on this playfield, it took over five minutes of rubbing the same spot to get down to the artwork, and the majority of the swirl marks were removed long before then. With all of the sandpapered areas, the swirl marks were still there until the topcoat was almost completely removed.
If that's not magic, it's damn close to it. For all the time that I've been in this hobby, one question that has come up repeatedly is "how do I deal with swirl marks on my playfield". And the answer had always been "clean it as best you can and learn to live with them". Now there is finally a better answer to offer.
Each pinball machine manufacturer used their own topcoat formulation, so these results may vary based on the brand and age of the game. Up until approximately 1990, all playfields had a lacquer-based topcoat, so these should all react similarly. 1990 saw the introduction of automotive-style clearcoats, which are both thinner and tougher than lacquer. The tests that I performed here don't apply to these playfields, so in those cases, "your mileage may vary".
The Magic Erasers work in two different ways. The main part of the pad works like very fine sandpaper to uniformly remove the topcoat, and the dissolved grains of the pad (in combination with a liquid like alcohol) help to clean the dirt out of the fine cracks of the top coat.
One potential problem that I foresee is a recurrence of visible swirl marks if nothing is done to seal the now-empty cracks in the topcoat. Perhaps a good coat of wax would be sufficient, but in my opinion it would be better to apply additional layers of topcoat, if at all practical. I prefer using acrylic lacquer, but a waterborne urethane or automotive clear would work as well, if not better. Lacquer is my preference because it is the original finish. Lacquer goes on "hot", which means that the new lacquer bonds to the old lacquer as one layer. Urethanes and auto clears seem to be more popular, and that is fine - this is a matter of religious importance to some. Regardless of the type of clear, Magic Erasers do a great job of preparing a playfield for its new finish. Along with the swirl marks and dirt, any traces of old wax and other cleaners are removed, and the surface is roughed up just enough to accept the new finish.
Hopefully, this page will expand with new uses and techniques for these Magic Erasers. If you have any additional information, links to useful information or just comments that you'd like to share, you can get in touch with me here.y & Links
Picture Gallery & Links
Here are links to other sites that have pictures and information pertaining to Magic Erasers
Here are before and after
pictures of a Stern Seawitch sent to me from Q Frost, showing how
effectively a Magic Eraser removed heavy swirl marks from the playfield.
Here's a before and after comparison of a Big
Indian playfield (1974 EM). Above, it's clear that virtually all of the dirt was
removed from the swirl marks, and that the cracks Below are before and after pictures from a
Williams EM playfield, courtesy of Chris (greenacarina). Original material ©
Copyright 2004 - Mark Clayton
Here's a before and after comparison of a Big Indian playfield (1974 EM).
Above, it's clear that virtually all of the dirt was
removed from the swirl marks, and that the cracks
Below are before and after pictures from a
Williams EM playfield, courtesy of Chris (greenacarina).
Original material ©
Copyright 2004 - Mark Clayton
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