The Art of Gorilla Glue Gilding

Jim Hingst

To many of his peers in the sign industry, Sal Cabrera has earned the well-deserved reputation as the “Gorilla Glue Guy.” Over the years, Cabrera has innovated new applications and perfected new procedures for Gorilla Glue gilding. Instead of using traditional size, he uses curing Gorilla Glue as his adherent, applying the gold leaf directly to the tacky adhesive. Gilding on this bubbly, foaming adhesive is perfect for fashioning organic shapes, such as leaves and trees.

This past summer, I had the opportunity to spend a few days at Cabrera’s shop in New Freedom, Pennsylvania and learn his unique process of gilding on Gorilla Glue.

Surface Prep
While Gorilla Glue sticks to just about anything, you still need to clean the substrate; otherwise the glue will stick to the surface contaminant instead of the sign surface.

For most applications, surface prep consists of washing the substrate with detergent and water. After rinsing with clean water, complete the cleaning process by wiping the surface down with isopropyl alcohol.

After cleaning a painted oval MDO sign blank, Cabrera applied R Tape 4075RLA application tape to the surface. While I worked on the border of the panel, Sal laid out the center of the design.

For sketching out your design ideas, high-tack application tape works great. Because it’s paper, you can draw directly on it with a soft pencil. If you don’t like your design, erase it. It’s also inexpensive, so if you change your mind about what you want to do, just rip it off and squeegee on a new sheet of application tape.

In preparing his layout—whether he’s working with application tape or vinyl paint mask—Cabrera designs cut lines, which divide the masking into workable sections.

Cutting vinyl paint mask on the plotter is often preferable to cutting paper application tape masking on the substrate, because it prevents cutting into the paint job. However Cabrera likes to cut right on the substrate. “I usually just apply the Conform® application tape directly to the sign, sketch my design on it, and then cut away with an X-Acto® knife and #11 blade,” says Cabrera, cautioning not to press too hard because you will cut deeply into the painted surface. “Also once you start cutting a line, don’t stop or the edge will be ragged.”

The Mixture
With the application tape masking cut and weeded, we were ready to apply the glue. Because the glue expands very fast—and cures fast too—you have to work fast. For this reason, Cabrera plans out how he’s going to work before he begins his project. He divides the sign into workable sections and applies the glue to one section at a time.

For most applications, Cabrera will pour a small amount of Gorilla Glue in the bottom of a wax-free paper Dixie cup (approximately 1/4-inch). To that, he adds two drops of water-based Createx™ pure pigment—which he buys at BearAir (—and one drop of water. He mixes up his concoction with a craft (popsicle) stick. (Note: As an alternative to the Createx product, you can substitute Ronan Aqua Leaf™. The Real Gold paint looks remarkably like real gold.)

The Createx pure pigment is available in six primary colors. While adding the pigment to the glue colors the mixture, it serves a much more important function. Mixed with water, the Gorilla Glue begins to foam within a few minutes. By adding Createx pigment to the mixture, Cabrera controls the amount of foaming. “If you use the pure pigment in the mixture, the glue will set up faster, which means that you have to work faster—a lot faster,” he says. “If you don’t add the pigment, you have a little more time to work, but the glue expands more and, in some cases, can get out of control.”

In areas of the country where the relative humidity is high, the moisture in the air will react with the Gorilla Glue, causing it to expand. If the humidity is low, you’ll need to add a drop or two of water.

How you mix the water in with the glue can produce a variety of effects. Spraying the substrate with water and then applying the glue results in an irregular pattern. Some areas of the design will rise and bubble more than others will.

Applying the glue onto a sign panel and spraying the surface of the glue creates an entirely different texture. Using this technique, the glue bubbles on the exterior surface, resembling the cratered appearance of Rice Krispies®. After the surface bubbles up, the dried glue can be ground down with a belt sander and gilded, producing a texture similar to that of a concrete block.

Applying the Glue
There are several ways to apply the Gorilla Glue. Cabrera’s favorite application tool is actually a small piece of Coroplast, which he uses to squeegee the glue over the part of the design he’s working on. The Coroplast allows him to apply a consistent layer of glue. If the design involves intricate detail, Cabrera only smears on a thin layer of glue.

Cabrera advises experimentation in mixtures and application techniques. “Only by pushing the envelope can you create new effects, which become part of your style that sets you apart from everyone else,” he says.

Another method, which Dr. Francis Lestingi of Signs of Gold ( in Williamsville, New York recommends, is to dab on the Gorilla Glue with chopsticks. Lestingi describes the technique as “stipple gilding.”

Removing the Masking
Immediately after applying the glue, be prepared to remove the masking. If you have any small pieces of masking in the centers of letters, remove those first. These are very easy to lose track of as the glue expands.

In removing the masking, you will occasionally remove some of the glue over your design. When this happens, you’ll need to perform some surgery. Cabrera often uses the tip of an X-acto knife to add a needed droplet of glue or the end of a quill handle to apply additional glue. You can also fashion your own tools from thin dowel rods.

Working with the Gorilla Glue is messy work. Wear latex gloves or clean up immediately after your hands get sticky to prevent your fingers from turning black from the residual glue. Moisten a paper towel with water and then spray the towel with Rapid Remover. Use the moistened towel to clean your fingers.

When the glue is curing, you can decorate it in a number of ways. For our project, we applied variegated leaf. Cabrera has also shaken glitter and abalone sprinkles over the drying glue. And Gorilla Glue also works great as an adhesive for smalt. The effect that you wish to achieve dictates the techniques that you use in mixing the adhesive, applying the glue, and decorating the design.

You can apply the leaf material about ten minutes after the Gorilla Glue has been applied and the masking removed. The glue cures quickly and, in no time, is tacky enough for gilding. At this stage, Cabrera lays the leaf.

Using either a mop brush or a soft bristle wash brush (shaped like a flat), Cabrera pushes the variegated leaf into the edges of the design.

The stiffer wash brush also helps you gently push the expanding glue back into place. Be careful not to touch the curing glue with your brush, or you’ll likely ruin it.

After you apply the leaf material, press it to tamp down any glue that has expanded more than you’d like.

Applying Texture
While the glue is still malleable, you can emboss it with various tools to create different surface textures. The edge of my business card works great in creating lines in the gilded glue.

One of Cabrera’s favorite tools for adding texture is an old burnishing tool that artist’s had used many years ago—B.C. (before computers)—to transfer Letraset press type letters.

Cleaning up the Sign Panel
In all likelihood, you’ll end up with glue in places where you don’t want it. Cabrera wipes away the unwanted glue with a mixture of water and Rapid Prep. He’ll also clean the surface with isopropyl alcohol or straight denatured alcohol for the stubborn areas.

The Finishing Touches
With the Gorilla Glue gilding complete, Cabrera outlines the design to clean up the edges. This gives the design a cleaner, more professional look. Selecting a contrasting color will help set the gilded design elements apart from the background.