4 welding hazards to watch for

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4 welding hazards to watch for

Metal welding ( welding ) means joining 2 metal pieces by heating them until they melt together, or using a welding electrode as filler to bond them.
Commonly used metal welding processes include the following:

1. Gas Welding
This is a fusion welding process. Its heat comes from burning acetylene fuel gas with oxygen. Complete combustion can produce a temperature of 3200 degrees Celsius without soot or smoke.

2. Arc Welding
Arc welding uses heat from an electric arc between the workpiece and the electrode. The electrode melts and supplies filler metal to the weld.

3. Press Welding
Press welding joins 2 metal pieces by heating the intended joint and applying pressure to the molten area until the pieces bond at a point or along a seam. Heat can be generated by electrical resistance, as in Spot Welding.

4. TIG ( Tungsten Inert Gas Welding )
This process uses heat from an arc between a tungsten electrode and the workpiece. Inert gas shields the weld area and molten pool to prevent reactions with the surrounding atmosphere.

5. MIG ( Metal Inert Gas Welding )
MIG welding uses heat from an arc between the welding wire and the workpiece. Bare wire is continuously fed into the arc and provides filler metal to the molten pool. Inert gas shields the pool from contact with air.

6. Submerged Arc Welding
Submerged arc welding uses heat from an arc between bare wire and the workpiece. Granular Flux covers the arc; flux near the weld melts and covers the metal, protecting it from reactions with outside air. The source states that flux farther away does not melt and cannot be reused.

Next, here are 4 categories of hazards that may occur during welding.

1. Arc radiation hazards
Besides the bright visible arc, invisible ultraviolet and infrared radiation can damage the eyes and burn the skin. Arc welders therefore need protective equipment meeting appropriate standards. Ordinary dark glass, and even gas-welding goggles, cannot protect against arc radiation. Ultraviolet radiation can irritate the eyes. Trainees who have not mastered raising and lowering their welding helmet may repeatedly look into the arc, causing a burning, gritty sensation in the eyes that can require several days of treatment. Severe carelessness can damage eyesight or cause blindness. This is one reason schools need designated welding rooms and workplaces should use screens to protect other people, including curious children, from looking at the arc.

2. Welding gas and fume hazards
Although an arc does not appear to be direct combustion, the source describes substantial oxygen loss during welding. Melting the electrode and burning its flux coating also generate fumes and polluted air, requiring good ventilation or extraction of toxic fumes from around the arc.

3. Heat hazards
Welding melts metal together, so the heat must be considered. Molten metal and slag can splash onto the welder or nearby objects and start a fire. Burns can be more difficult to heal than other injuries, so safety and personal protective equipment must not be neglected. Metal may be extremely hot even without glowing. Make sure before touching it; using tongs is preferable. Keep combustible materials out of the area within approximately 10 metres of the weld. The source suggests preparing dry sand for emergency fire response.

4. Potentially fatal accidents
Electricity cannot be seen. Welders must not be careless. The source refers to reminders in Germany not to weld with bare hands; protective gloves are necessary against possible hazards.