Reflector Tape

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By Bob Cox

Are you looking for a low-cost, light-weight way to make parts of a model light up and glow? Do you want to make a lost rocket easier to find at night? Are you having troubling painting the interior of tube fins? If so, then reflector tape might be just what you need.

I used reflector tape heavily on my QModeling RMS-Andromeda:

• The inside of the ram tubes were lined with red tape to simulate a fusion reaction glow.
• Blue strips on the outside of the ram tubes simulated guidance lights.
• I used a paper punch to create glowing round porthole windows along the crew compartment.
• The round hatch covers on the tail fins look like white spotlights.

I have also used reflector tape on other kits. For example, I used reflector tape instead of pinstripe tape on my Estes Executioner.

Theory

When exposed to flash (or any light source), tiny beads in the tape act like retro-reflectors, returning most of the light back toward the light source regardless of the angle of incidence. (Normal mirrors will only reflect back to the light source if it is perpendicular to the mirror's surface.) If the light source is near the camera lens or a human eye, the tape will return far more light than the diffuse reflection from the rest of the model, making the tape appear to glow as if it had an internal light source. The effect looks similar to electroluminescent panels, but is far cheaper, lighter, and easier to use.

PROS:
+ Low cost. I paid $1/roll for red tape on sale.
+ Light weight.
+ Easy to apply.
+ Covers spirals without lots of filling and sanding.
+ No batteries.
+ No wiring.
+ Maintains color even in bright light.

CONS:
- The effect only works under certain lighting conditions:

• There must be a light source very close to the camera or observer's eye. The effect disappears quickly when the light source is moved off axis.
• If the ambient light is too high, the glowing effect gets washed out.
• If photographed from too close, the flash lights up the rest of the model as much as the reflector tape, spoiling the effect.

Daylight Appearance

When I described this technique on The Rocketry Forum, one poster questioned how good it would look in normal light without the benefit of flash photography. Of course no lighting system (reflector tape, electroluminescent panels, LEDs, etc.) is going to look as good in broad daylight as it does glowing in low light. Unlike LEDs or EL panels, however, reflector tape still looks pretty decent even in normal lights, as these photos show.

Without flash, the windows in the Andromeda’s crew compartment are nearly indistinguishable from the plain white circles on the stock decals. No improvement, no degradation.

Without flash, the round hatch covers on the tail look like they are painted silver. The blue rectangles still have a distinct blue color. No improvement, no degradation.

All in all, the reflector tape doesn't help much in daylight, but it doesn't hurt at all.

Finishing Tube Fin Interiors

Tube fin interiors are inherently tough to finish since they often have deep spirals, do not have a glassine coating, are hard to paint without getting runs, and are hard to reach for sanding. Applying tape to inside of tube fins is easier and looks better than most paint jobs I have seen on tube interiors.

When I installed the red tape inside the Andromeda’s tube fins, I originally planned on running the strips circumferentially so that the seams would not show. However, while trying to stick the tape into place on the inside of the tube I found that it was almost impossible to make it straight. After about an hour of screwing around and still not having one tube done, I decided to abandon that approach.

I ended up with four strips each running lengthwise inside the tubes. Each strip was cut to approximate length and then stuck in place. Each strip overlaps its neighbor. After all four strips were stuck down, I used an X-Acto blade to trim them flush with the ends of the tubes. The photo below shows the tape before I trimmed it. I suppose I could have cut along the seams to eliminate the overlap, but it doesn't look too bad the way it is.

The tape seams inside the tube are barely visible in the photo below, but I don't consider them terribly objectionable. Applying the tape was certainly easier than trying to get a glossy, spiral-free finish inside the tube using spray paint.

Other Colors and Where to Buy Them

Red and white reflector tape is available from most hardware stores or auto parts dealers. Other colors are far less common.

I found an eBay vendor, ColeDiscount, who was selling reflector tape in a variety of colors. I bought 7-inch strips labeled as 'arrow cap wraps', but they also sell strips in different lengths or by the roll. Even though they don't list any mixed-color packs on eBay, I got a variety pack in my choice of colors just by asking.

I was surprised to see that they also sold black reflector tape. "Black reflector" may sound like an oxymoron, but it works pretty well. In normal light it looks like black electrical tape; when flashed, it has a silvery-gold glow.

Inspired by Hollywood

I got the idea for using reflector tape from a TV special about the making of the 1990 Arnold Schwarzenegger movie 'Total Recall'. The climactic scene in that movie takes place on Mars and involves a giant underground reactor and a huge reservoir of ice. When the glowing turbidium reactor rods are jammed into the ice, the ice vaporizes and quickly covers Mars with a breathable atmosphere.

To film that scene the special effects team needed a way to make the reactor rods glow. This was back when computerized graphic rendering was still pretty expensive, so the effect was done optically with miniature models instead of in post-production. Rather than wire the model with lots of little lights, the effects crew merely wrapped the rods with white reflector tape. When they shot the scene, light banks were placed right next to the camera lens. By changing the color and intensity of the light banks, they could easily make the rods appear to pulse and change colors in a controlled manner.

GUEST's OPINION:
"" (X.X.)