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Pinball Rehab

pinball repair and restoration

Recreating Plastics Recreating Plastics Hot

There are times when your only choice is to recreate a plastic for you pinball.  If no replacement parts are available you have no other choice for heavily damaged or yellowed plastics.  In my case I've got two yellowed plastics from a Bran Stoker's Dracula that need to be replaced (see Image 1).

Nothing too dramatic needed as far as tools for this project (see Image 2).  You'll need a Dremel tool with a cylindrical high speed cutter and a buffing wheel, some white rouge (buffing compound), a coping saw with a fine blade, a variety of files (flat, round, curved and medium to fine cut) and a utility knife.

Note: You could use a jigsaw with a blade for cutting plastic.  Although it really goes pretty quickly with the coping saw and you have finer control.

In my case the plastic was 3/32 of an inch thick so I just picked up a piece of .093 Lexan (polycarbonate) at Home Depot for about five bucks.  It has a protective plastic sheet on both sides which is great for protecting the plastic as you're working.

You could also use sheet Acrylic, but the polycarbonate products are stiffer and slightly stronger.

Image Gallery

Recreating Plastics
Recreating Plastics
Recreating Plastics
Recreating Plastics
Recreating Plastics
Recreating Plastics

My first piece is basically a square with rounded corners and a couple of mounting holes.  The first step is to use a pen and the original plastic to mark your cuts.  With straight edges you can score the plastic using a ruler and utility knife.  Just pop it in a vise and bend the plastic over till it cracks along the line.

This gives you a nice clean edge so minimal touch-up is required.  I rounded the corners using a Dremel tool with a high speed cutter and then lightly hit each side and the corners with a fine file.  I then polished the edges, after removing the protective plastic sheet, using the Dremel with a buffing wheel and white rouge.

In both cases keep the Dremel at a fairly low speed since it's easy to overheat the plastic.  Also keep the bit moving and don't linger in one spot.

I used the cutter bit to create the open screw hole and for the other used a two-speed drill on the low speed.  A little cleanup was required around the hole I created with the cutter bit, which I'll cover later.

My second piece was a lot more complicated with a lot of curves.  Any straight edges can be cut by scoring the plastic as described above.  Note: The score has to go all the way across the plastic piece you are breaking off so you may have to make additional cuts for each side of the break.

For my first attempt I used one of those wood working kits that consist of a soldering iron and an X-Acto blade and some other accessories we don't care about.  It was very slow going and a lot of melted plastic built up on the top and bottom corners of the plastic (see Image 3), which required a lot of work to remove. 

After this failed attempt, I moved on to a coping saw.

If you have long straight or slightly curved cuts lower the handle of the coping saw towards the plastic and you'll get a straighter cut.  In other words. the saw will be less perpendicular to the plastic and more parallel.  For sharper curves you want to be more perpendicular.

Once the piece is cut out you can use the Dremel with the cutter bit and/or your files to finish shaping the plastic and smooth the edges (remove the plastic protector at this point).  Use the Dremel and medium files for shaping and always finish up with a fine file.

Once you're done you will have a curled edge on the top and bottom of the plastic (see Image 4).  You can clean this up by using either a fine file or a utility knife (see Images 4--that's rust on the file, not blood--and 5).

Hold the file at a 45 degree angle to the plastic and pull it across the edge (towards you) and down (at the same time).  If you're using the utility knife, place it at a 45 degree angle and pull towards you along the edge of the plastic.

Finish up with the buffing wheel and rouge, drill any mounting holes and you're done.

In my case the mounting tabs on the second plastic where slightly off which was caused by trying to use the soldering iron and blade technique.  They would have turned out much better using the coping saw, but no one will ever know but me.