The BROCO Ultrathermic electrode consists of seven small rods inside a thin steel tube. One of the seven rods is a special alloy that will burn independently after an arc is struck and oxygen is flowing through the tube. The remaining six rods are made of mild steel. The electrode is insulated with electrical tape. The 3/8-inch electrode is 18 or 36 inches long; the 1/4inch comes only in 18-inch lengths. It will fit Arcair’s Sea Torch, BROCO’s BR-22 Underwater Cutting Torch and Craftsweld’s Arc-Oxygen Cutting Torch by using the proper collet and washer combinations. The ultrathermic electrode will melt almost any material with its 10,000 degree F plus, tip heat.
The Arcair Sea-Jet cutting electrode consists of a thin mild steel tube enclosed in a spiral, mild steel spring-like wrapping, which is encased in a larger metal tube (see Figure 2-2d). The electrode is coated with waterproofing and insulating material. Like the Ultrathermic, the Sea-Jet will burn ferrous and non-ferrous materials such as concrete, rock, barnacles and other sea growth. The electrode is 3/8-inch in diameter and 18 inches long. It will also fit the Arcair, BROCO and the Craftsweld Torch.
When using the Ultrathermic or Sea-Jet cutting electrodes, an adapter kit will be necessary in order to achieve proper fit of the electrodes. The kits consist of a variety of collets and washers designed to adapt the torch for the standard 3/8- and 1/4-inch electrodes. Smaller adapters are available for other cutting or welding operations.
Exothermic Electrodes amperage requirements
The exothermic electrodes will sustain ignition without electrical power as long as oxygen is flowing; therefore, the diver may call for SWITCH OFF once the electrode is burning. Although the exothermic electrodes will continue to burn when the current is off, it is recommended that electrical current be used to provide more heat and enhance the cutting process on all conductive material.
The Sea-Jet electrode will operate on a wide range of amperage settings up to 400 amps. A 12-volt DC battery may be used for start up power and satisfactory cutting can be performed without power, however, the use of 200-300 amps will produce optimum cutting results. (Manufacturer’s recommendations)
Correct power settings will result in quick, efficient cutting. The ultrathermic electrode requires
only 150 amps at the torch working depth, as opposed to 200-300 for the Sea-Jet. Excessive current
settings for the ultrathermic will result in rapid consumption of the electrode. With proper
oxygen and power settings, the exothermic electrodes will burn for 45 to 55 seconds. A tong test
ammeter is extremely useful in determining the exact amperage being used at the work piece. Do
not rely solely on the values as indicated by panel control knobs or meters, as these are not always
accurate. Simply encircle the negative (-) welding lead with the tongs of the amperage tong meter
and close them. A clear, accurate reading is instantly registered on the scale. The tongs open by a
slight pressure of one finger on the trigger and are self-closing.