Working With Gerb Effects
Often called a "spark fountain," a Gerb effect produces a jet of sparks that can shoot anywhere from six to fifty feet into the air and last up to twenty seconds or more. The fallout from most Gerbs is "clean", which means that they can safely be used in the vicinity of actors and scenery. This property has made Gerbs a very popular effect for live theatre, rock bands, and special events. Gerbs are also hugely popular with professional wrestlers, who use them to make their entrances to the ring more dramatic. This week, I'd like to look at how to use Gerbs to create a great-looking, safe effect for your next production.
When selecting a gerb, there are three variables that you will have to address: height, duration and color. The product descriptions for all of our gerbs will specify how tall the effect is, how long it lasts and, if applicable, what color choices are available. Each Gerb has a set of two numbers which designates the Gerb size. The first number shows the burn time (in seconds) and the second number shows the height (in feet). The height is defined as the top of the main plume, some sparks will go higher, some lower. For example: a 1/4 x 20 is a Gerb of 1/4 of a second duration that reaches a height of 20 feet. In recent years, for added safety, the "height" number is a bit on the conservative end (most sparks will be 1-2 feet lower). To choose the appropriate height for your effect, consider the space in which it will be used. If you're in a club or restaurant with low ceilings, you'll want to stick with one of the smaller effects, while the larger Gerbs could be used at an outdoor show, or in a large theater. As a general rule, you don't want to use any effects that are higher than 75% of your total clearance. Example: if your ceiling is 20 feet above the stage floor, you don't want to use anything taller than 15 feet. Many fire departments have stricter rules, requiring effects no more than 50% of total clearance. Always consult with your AHJ (Authority Having Jurisdiction) prior to purchasing or using any pyrotechnic product.
If you'll be using the Gerb in very close proximity to a performer or audience member (in a tabletop centerpiece, for example) you should probably consider using an Ice Gerb or Kool Fountin. These fountain produces a spark effect that is much smaller than a typical Gerb (about 6-8 feet for the Ice Gerbs and around 30 inches for the Kool Fountains) and burns at a "cooler" temperature. Contrary to what the names infer, these effects still burn quite hot and the same amount of care is required for their safe use. Also, while we advise against the practice, some performers have been known to hold an Ice Fountain in their hand while it burns, and we've no knowledge of any unusual problems resulting from such use.
When deciding on the duration of the effect, consider both how you want the effect to look and when in the show it takes place. If you are using your Gerb indoors, in the beginning or middle of your event, you'll want to use the shortest duration you can get away with. This reason for this is simple: the longer a Gerb burns, the more smoke it creates, and your audience doesn't want to sit in a room full of smoke. If you really want to use that 20 second Gerb, use it at the end of the show so that the audience can quickly get out of the smoke.
Depending upon the type of gerb that you choose, you may or may not have a choice of colors. As a rule, all gerbs by all manufacturers are available in silver, but other colors may be available for specific gerbs. For example, the standard Gerbs by LeMaitre and Ultratec are primarily available in silver. They are also available in Gold (due to extra safety concerns, Gold Gerbs are not very popular and only a few sizes are available. More info about Gold Gerb safety concerns can be found later in this article). The Angel Fire Gerbs and Kool Fountains (Ultratec) and the Ice Gerbs (Le Maitre) are also available in many different colors. The sparks produced by all of these colored Gerbs are Silver; however, the flare base (the bottom section of the effect) is bright with vivid color, which creates the illusion of colored sparks. These truly are beautiful effects!
The color you choose is really just a matter of personal taste as the color of the Gerb doesn't noticeably change its performance. But if you simply must have a Gerb in Gold (or red, or green, etc) be aware that it will limit your selection of options for durration and height.
Gold Gerb Safety: It is extremely important to note that Gold Gerbs are more dangerous than standard (Silver) Gerbs. This is due to the fact that the metals/chemicals used to create a Gold pyrotechnic effect require much higher ignition points (they burn hotter) and the amount of fallout increases. "Fallout" refers to the amount of residue produced from a pyrotechnic effect. Silver Gerbs have very little fallout (they are relatively "clean") and, while they do produce smoke, they leave very little residue (if any) on the stage. Gold Gerbs are quite the opposite! While the effect is quite beautiful, they produce more smoke, have "possible hot fallout", and will leave some residue on the area around the effect. Extra care must be taken when using these effects!
Even though Gerbs are one of the safer pyrotechnics, it never hurts to use some common sense when setting up your effects. First, you should never place any pyrotechnic so that it's right next to or pointed directly at a piece of scenery, as this can cause scorching or, in extreme cases, start a fire. Allow at least a foot or two of clear space around the Gerb and make sure that the spray won't hit any nearby curtains or scenery. You'll also want to provide a clear line-of-sight from the operator to the effect. The operator makes the final call on whether or not it's safe to fire the effect, so make sure your effects operator is someone whose judgment you trust and has been properly trained to operate these effects!
Theatre Effects Customer Service Department
Theatre Effects, 1810 Airport Exchange Blvd. #400, Erlanger, KY 41018
Phone: 1-800-791-7646 or 513-772-7646 Fax: 513-772-3579