For years I have recommended edge sealing the RTape VinylEfx® films with SuperFrog’s Frog Juice, which is an acrylic enamel automotive grade clear coat. While it is great for protecting vinyl graphics, you can also use it for other applications, such as clear coating digital prints and even gold leaf.
Frog Juice is available in quart and gallon cans and in aerosol cans at many sign supply distributors in the United States and Canada. Although you can apply Frog Juice with a brush or roller, some prefer spraying the clear coat on. Spraying applies the Frog Juice evenly, with no brush marks. If you apply Frog Juice with a brush, you can use the clear coat straight out of the can. Spraying requires that you thin the product.
When spraying with an airbrush, Butch “SuperFrog” Anton recommends that you thin Frog Juice at a ratio of 75% Frog Juice to 25% mineral spirits. As with other coatings, the Frog Juice should have the viscosity of milk. Variations in shop temperature may require more thinner. When adding thinner to the mixture, add a little at a time until you attain the desired consistency.
When spraying the clear coat, Anton recommends two coats of Frog Juice. “With normal shop temperatures of 65°F to 70°F, you can lay down one coat, wait 10-15 minutes and then lay down a second coat,” Anton says. “To achieve a uniform appearance, I spray the Frog Juice on in a cross pattern – first, horizontally, then vertically.” After spraying on the clear coat, you generally will need to wait twelve hours for drying.
“When you are spraying, you should lay it on wet so you don’t end up with an uneven orange peel appearance,” says Anton. “Just make sure that the coating isn’t too wet or it will take forever for it to dry.”
Anton recommends using mineral spirits to thin Frog Juice, if it needs it. “You can use other solvents to thin Frog Juice,” Anton says. “People have used automotive acrylic enamel reducers, lacquer thinner, and naphtha. All of these products are hot thinners and can react with the paint.” If you are going to reduce the clear coat with a hot solvent, you need test it before you use it in production.
You can spray Frog Juice using a HVLP spray gun at about 40 psi. Spraying a couple of light coats of Frog Juice is preferable to spraying one heavy coat. A heavy coat will take longer to cure. While it is curing, be careful not to touch the coated area or you will leave your fingerprints in the “juiced” areas of your signage. Normal drying times will vary depending on the method of application and the ambient temperature of your shop.
After spraying Frog Juice, you are usually good to go in about an hour or less. To speed up drying times, try directing a high volume fan on the clear coated graphics. If you have to add mineral spirits to thin Frog Juice out for spraying, it can take longer for the clear coat to dry.
Of course, if you don’t have a compressor and spray gun or don’t want to go through the bother, you can always use the Frog Juice that comes in the aerosol cans. Spraying with the aerosol product gives you a nice even coating. Many sign makers, who are printing with thermal transfer printers, such as the Gerber Edge, recommend protecting prints with the spray version of Frog Juice.
If you are brushing on Frog Juice, you can apply it with a foam brush or a bristle brush. Frog Juice right out of the can has the viscosity of a watery maple syrup. For most applications, you will not need to thin the clear coat out. Over time, however, Frog Juice or any other clear coat, for that matter, can thicken, especially if you leave the lid off of the can.
If the consistency of the clear coat becomes too thick, you can always thin it out by mixing in mineral spirits. You can usually add as much as 10% mineral spirits to the clear coat.
I prefer brushing on Frog Juice, because I feel that with a thicker coating of clear coat, you are afforded more protection for your signage. Usually, any brush strokes will level out. For a smoother appearance, you can always apply the first coat by brush. Afterwards spray a final coat using the aerosol version of Frog Juice.
If you use Frog Juice to clear coat gold leafing, experienced gilders recommend applying three coats, un-thinned right out of the can. Make sure that the gold leaf size has fully cured before clear coating. After clear coating the first coat, wait at least 12 hours before applying additional coats.
You can also spray a finish coat using an automotive acrylic urethane clear. Frog Juice is generally compatible with a wide range of paints and clears. To prevent any adverse reaction between different paints and clear coat systems, the best advice is to read the instruction and, before going into production, TEST, DON’T GUESS. When spraying aurethane clear over a Frog Juiced graphic, be sure to allow plenty of time for the Frog Juice to thoroughly cure before spraying the automotive clear.
If you follow the instructions for using Frog Juice, you should expect extended durability of your graphics. The specialty film, shown in the picture below, was coated more than 15 years ago.
