login/register

Pinball Rehab

pinball repair and restoration

Repairing Broken Ramp Mounting Tab Repairing Broken Ramp Mounting Tab Hot

This procedure works great for replacing (as compared to reattaching) a broken mounting tab on a ramp or plastic. The product I'm using, Plastex (see references) is a two part resin kit consisting of a powder and a liquid that when mixed together turn magically into plastic.

The kit also includes a molding bar, which is hard at room temperature and pliable at 170 degrees, for replicating the replacement part from a sample. A video included in the package thoroughly explains the techniques used to recreate your part.

This product has been used for years on plastic motorcycle parts and is a perfect solution where you're more concerned with structural strength than appearance. Note: The finished product will have a slight yellow tint and the line between the original plastic and the Plastex will be visible.

In Image 1 you can see a ramp from a Williams Dracula where the plastic is broken around the mounting screw.

The first step is to create a mold from one of the intact mounting holes. I used a heat gun (set at 200 degrees) to heat the molding bar and then pressed it in place (see Image 2).  It will harden in a few minutes and can then be moved to the damaged area and clamped in place (see Image 3).

Image Gallery

Repairing Broken Ramp Mounting Tab
Repairing Broken Ramp Mounting Tab
Repairing Broken Ramp Mounting Tab
Repairing Broken Ramp Mounting Tab
Repairing Broken Ramp Mounting Tab
Repairing Broken Ramp Mounting Tab
Repairing Broken Ramp Mounting Tab

Slightly overfill the area with the Plastex powder (see Image 4) and then add the catalyst (see Image 5). There is also a technique where you add the catalyst to the powder in a separate container and then move the plastic ball to the mold and add more catalyst.

Whichever approach you choose it does take a little technique and it is best to practice on some scrap materials.

Let the ramp sit for about an hour and then remove the clamps and molding clay (see Image 6).  It's a little rough, but nothing a little sanding and polishing won't take care of.

I trimmed the excess plastic and cleaned up the hole with an X-Acto knife. I then started with 220 grit sandpaper and moved through 400 grit, 600 grit, Novus 3 and Novus 2.  You can see the finished product in Image 7.

You can also use Plastex with a fiber reinforcement cloth if a stronger joint is needed.  Although I would only do this if the repair was hidden by other playfield objects.  Plastex also works well for repairing stripped plastic threads.

See the reference for an article that includes the Plastex instructional video.