Renovation of a Space Shuttle Playfield


Introduction

In August 2005, while shopping for a backglass, I came across an old Space Shuttle playfield that had been mylared from day one.  Seeing the nice results that others have obtained with this starting point, I decided to give playfield renovation a try.  

The Playfield Rotisserie

Prior to this point, I had been reading the RGP newsgroup for a few months, and became familiar with a tool called a "Playfield Rotisserie".  This device allows access to all sides of this heavy and delicate item by allowing it to be rotated along its long axis. 

Examples:
Instead of buying a commercial unit, I decided to design my own.  While looking around Lowe's home center, I hit on using a pipe union as the key element of my playfield rotisserie.  This component could be used as the hinge, and as the means to lock down the angle of the field.


One end of the playfield rotisserie.  The key component is the pipe union between
the two flanges.  It functions as both the hinge and the locking device.
Each of these assemblies is 4" in length.  Add two to the 42" playfield,
and the distance between beams is 50".  Make sure all joints are tight.

In the picture above, the 2x3 is clamped to a table top, which cantilevers the playfield out in the open.  A "floor flange" is screwed to the wood with three wood screws.  From there, a nipple is threaded into the flange and connects to the pipe union.  Another nipple, and another flange leads you to the angle iron where the playfield is mounted.  The same mechanism is built for the other side.  All hardware is 1/2" pipe, and was purchased from my local Lowe's, and costs almost $40 total.  I did not need to cut or drill any metal for the construction.  Make sure all joints are very tight so that the playfield will be stiff when the union is tight.

During construction, make sure the rotation axis of the two unions are as aligned as possible by careful measurement of the distance from the table and other offsets. After building up the two sides, I gently lowered the playfield onto the angle irons.  They were then fastened down from below and with small C-clamps. Once completed, the unit rotated very well, and felt balanced.  I initially thought of putting a small amount of grease in the unions, but decided against it after assembly.  Make sure you put the same side of the two unions facing the same way.  This way you turn in the same direction on both unions for loosening and tightening.


The rotisserie allows easy access to the patient.  As for the playfield, it is in extremely bad shape. 
Very dirty, but hopefully it can be refurbished with time and care.  The plastics are
complete, and arrived packaged separately (ramps sort of visible in the top left).

One aspect I like about the above design that I have not seen anywhere else is that the playfield is cantilevered out into free space.  This allows me to work at the field like sitting at a table, with my chair under it.  I can of course tip it like a draftmans table for the optimum angle.  I can also crawl under it to pass wires, or to have a buddy thread a part through from the top to the bottom.

Note that it is also possible to use this idea with the wooden beams in a vertical position.  They could be bolted to the sides of a table or a floor stand.  This was my original idea, but the design evolved a bit.   Another variation is to use beefier gauge pipe (such as 3/4" or even 1") in case the friction of the 1/2" union is insufficient.  In my case, if I use a set of channel-locks to tighten them, the friction is very high due to the large surface area inside the union (to form a water tight seal).

Update, from Michel Oversteyns (on 3/3/06):

Your website looked familiar, but then I found out why... I used the
same technique you used to make a playfield rotisserie! Thanks for the
idea!

I modified your design a bit to make it look like the original metal
playfield rotisserie which could easily be taken apart and stored. The
only difference is that I made it out of wood.

My problem was that my desk was not long enough to attach the wooden
bars to it. So, I bought a large rectangular piece of wood, mounted 2
wooden bars under it over its entire length (for strength), and that
whole piece is put on my desk. It's heavy and rigid.

On top of that, I build 2 upside down T structures out of wood on which
I attached the plumbing parts, like you did. Those T structures are
fixed to the big rectangular piece of wood using wing bolts. The
playfield then goes between these 2 T structures. Looks wonderful! :-)


A nice addition to the table mount rotisserie to make it floor standing.  These two uprights
are bolted to a rectangular base to ensure they stay upright.

Another person that used this design (Chris Hibler)

The Original Condition

Some pictures of the playfield before I started work on it.  At this point, I had only
removed the plastics to afford a better view of the playfield.


Top of the playfield.  Lots of dirt everywhere.  The ramps were shipped separately, so they are not seen here.


Bottom of the playfield.  The mylar has protected the paint over the years, but has nicks in it.  As a result,
my initial plan of simply buffing the mylar won't work.


Top left corner with the pop bumpers and the Hubble graphic.  Throughout the renovation, I
will show this angle the most.


The Shuttle toy.  Phew.  Lots of work needed.  Note the large crack near the entry hatch,
more dirt, and the usual broken wing flaps.


The bottom right corner (where the ball eject mechanism is) had a split in the narrowest part of the
playfield.  When I found this, my heart fell, as I did not know if I could repair this problem.
The split is visible as the dark line, and extends downwards.  Sorry, for the blurry image.

Stripping the Playfield

The first job will be to strip the top of the playfield of all parts.  After a few days of intermittent work, all the hardware on the top of the playfield was removed.


The view of the top left with all the parts removed.  Note the really dirty pop bumper mylars.
Some of them have curled up, and allowed dirt to enter underneath.  Note also the mini C-clamp
at the top of the image that was added after the discussion on RGP.


I repaired the crack in the playfield with epoxy, and the result turned out great.  I was relieved to
find that the playfield was not warped after I was done, and after some light sanding, the
repair is not visible from the top side.  Note the bead of epoxy on the inner corner.

With the parts removed, I started to clean the exposed areas of the playfield with alcohol and a Magic Eraser. 
I then moved onto mylar removal.

Mylar Removal

There are three prevailing methods to removing mylar: the first is to use freeze spray to solidify the glue, the second is to dissolve the glue with a solvent such as Goo-Gone or Naphtha, finally, the third is to use a hair dryer to soften the glue (see links below).  I decided to start at the pop bumpers because that part of the playfield is partially hidden.  This would allow me some mistakes.  Also they were extremely dirty.  I started with the freeze spray, and found that the glue was still fresh enough that the mylar would not budge (I did not pull very hard).  I then switched to Goo-Gone, and it readily dissolved the glue (with some patience), and I did not even need to use a razor.  I finished the removal of the three mylars and residual glue with the solvent.


Tight shot of the pop bumper mylar during its removal.  Note the nice clean paint underneath.


The discarded pieces of mylar.  There were only a few pin points of what could be paint.
The rest was clearly dirt.  I was very pleased with the result.


The top left area with the pop bumper mylar removed and lots of cleaning with alcohol and Magic Eraser.
Note the nice clean area under the ramps (open yellow parts on the right).  The main playfield mylar is
still in place.  Note also the dark line across the Hubble graphic (visible before) cleaned up completely.

After the popup rings were removed with Goo Gone, I proceeded with the top of the playfield (the USA lanes) with the same solvent.  However, I noticed that the playfield mylar felt different than the popup mylar.  The popup mylar was thick and sticky, while the playfield mylar was hard, thin and felt very "old".  Nevertheless I continued, but unfortunately lifted paint near the popups.  Afterwards, when I was cleaning the glue residue, I noticed that it did not readily melt with the Goo Gone.  I suspect that I was effectively pulling on the mylar without the Goo Gone having softened the glue (!).


Mylar removed with Goo Gone from the upper playfield.  Note the paint loss near the pop
bumper area 8-(.  The text at the top sees a LOT of wear and is damaged on all my playfields.
I noted that there is white paint as the lowest layer of paint, which is easily disolved in alchol.
The next layer up is a wide orange line, and the top layer is the black.  Only a thin line
of orange is visible.  I adopted this same layering in my painting technique.  The last color
applied is black.


The same area after touching up.  I painted the text area with a needle to get the fine control.
Fortunately, the bottom area in the photo is partially hidden by the pop bumpers.  I used
hobby acrylic paint and was able to match the colors extremely well.

Seeing the awful results I obtained with the Goo Gone on the playfield mylar, I decided to give the freeze spray method another try.  It seemed to me that if I got the glue cold enough, it would act as a concrete barrier to actually protect the paint underneath.  I could then use a solvent to soften the glue and remove it chemically.  I figured that it would result in the least stress on the paint.

After some trial and error, I hit on a method that was very successful using a razor and the spray:
  1. Spray local area with Freeze Spray, including under the mylar edge that is already up, and the razor itself.  The idea is to get and keep the glue very cold especially the part that the razor is touching.
  2. Press very gently with a rocking motion (left and right motion) against the edge of the mylar. 
  3. As soon as the glue is cold enough, it will get very brittle, and you can actually "cleave" the glue with a satisfying crackling sound.  Note that very little force is needed, as soon as the glue is weak enough it will just crack!
  4. Make sure the area is kept cold with drops of Freeze Spray.
  5. Once the mylar is gone, cleanup the glue with alcohol and Magic Eraser.
Make sure the razor is kept clean and does not pick up glue during this process.  A clean razor will concentrate the force of your finger onto the front sharp edge.  During cleanup, the Magic Eraser (ME) really shines (hah), paper towels tend to absorb the alcohol, and the playfield dries up.  ME keeps the liquid onto the playfield, softening and absorbing the glue into its matrix.  It also appears to be very gentle on the exposed paint.
The biggest danger is removing up wide strips of mylar (like the middle part of the playfield).  It is very easy to pull on parts of the mylar sheet that is away from the cold spray, which will bring up paint.


Using Freeze Spray and a razor to remove the mylar.  The sharp edge of the razor is used
to 'cleave' the glue once it is cold.  In this state, the glue will be so hard that you will be unable
to scratch it with the razor held at tangential angles.  This will protect the paint from the razor.

During this process I also watched TOP#3, which shows the three methods described.  The DVD is highly recommended.  In this video, Shaggy simply picks the mylar up once it has been sprayed, but in my case, the plastic material was so old and brittle that it would break into little pieces as I pulled on it.  So I developed the alternate method instead.  In TOP#3, Shaggy actually injects the Goo Gone with a syringe under the mylar.  I did not do this (just sprayed it on the edges), so it makes sense that my efforts were so unsuccessful.
As for the glue cleanup, I tried alcohol, Naphtha and Goo Gone by squirting a few drops onto the glue and then covering the area with clear plastic wrap to limit evaporation.  After 10 minutes of waiting time, only the alcohol had softened the glue significantly.  This does not match the experience of others.  Perhaps the mylar glue that used was very old, or an unusual type.


Mylar removal and touchup painting done.  Phew!  I have learned a lot about mixing and applying paint.
One tool is the bottle of Acrylic Flow Improver at the top of the image.  It touts the ability to reduce the
"blobbing" of acrylic paint without diluting the color like water will.


Repeated from earlier in this document, this is the before picture.


One trick I developed during the repainting was to draw very thin straight lines using a straight edge with
an overhang and a needle.  I realized that my boy's Lego set offered up raw material for tools.
Note that I decided to also paint the tops of the pop bumper bolts although they are hidden by the pop bumper skirt..

At this point, I decided to take a break from mylar removal to address some other components of the playfield.

Playfield plastics

One large cosmetic factor is the playfield plastics.  There has been a lot written about restoring them (see links below).  The set on Playfield B was warped due to heat from the lamps.  I first straightened them by putting them in my toaster oven set to 250F.  They were set in a tray made from a folded piece of non-stick parchment baking paper.  After a minute or so, they were soft, and I then flattened them in a book.  I was surprised, it really does work!


After they were flattened, I removed the big gouges with 800 grit sand paper, and then
used my random orbit buffer with some rubbing compound to smooth them out.
I then finished up with Novus 2.  They turned out as shiny as a mirror.
When using the rubbing compound makes sure to keep the pad damp.

After they were clean and polished, I finished with the paint touchup.  In the example below, I first use opaque masking tape to mask off the black line (next to the blue field).  This allowed me to easily paint the black line.  The opaque masking tape allowed me to check alignment by holding the plastic up to the light as the black line is not visible in the back.  After that was dry, I filled in the red and blue behind the black line.  The alignment is very close, but matching the colors were more challenging.  I had to reduce the amount of blue applied to a thin film or else it would be too dark in translucence.  This caused the blue to look a little light in reflection as can be seen below.  This implies to me that the original blue ink is very dark and is applied in a thin layer.


Afterwards, I touched up the paint on the plastics.  Before (left/top), and after (right/bottom).  The red is "Cardinal Red",
and the blue is "True Blue". I had to balance the right look in reflection (shown here) and translucence (backlit by playfield lights).

I was also able to glue pieces together end-to-end by using plastic tape on the non-paint (front) side to line the pieces up, and then folding the seam open to drip epoxy into it.  Once it is folded flat, I added some more on the back. After touching up with paint on the back, it looks reasonable good.  We will see if this passes the test of time.


Main Space Shuttle Pinball page

Back Home

(c) Edward Cheung 2005, all rights reserved.