The biggest hazard related to arc welding is the arc- radiant energy. The arc is easily 2-3 times as bright as the sun and presents the same dangers magnified.
Looking directly at the arc causes a condition called arc flash. The vision effects range from nothing to temporary bright spots in vision, to temporary blindness, to permanent blindness. The physical effects include what is essentially a sun burn on various layers of the eye. The condition results in extremely painful swelling and burning of the eye and can include detached retinas. There are few treatments, the best is specific drops from an ophthalmologist, but this condition (like a sunburn) can take time to develop, so outside of business hours brewing chamomile tea to drink and putting the (cool) tea bags on the eyes can help ease pain from the tannins. Drinking the tea will also contribute to the recovery process. Cucumbers and ice packs can also provide relief. A significant risk of infection is present and may require antibiotics to treat. This is not a condition to ignore, because permanent blindness from a secondary infection is a real possibility.
It is imperative that a sufficiently dark welding helmet is worn at all times. For MIG and TIG welding, shade 11 is recommended. Most helmets have an adjustable dial for darkness and should be verified prior to beginning to weld.
MIG produces far more sparks and splatter than TIG. If TIG is producing a lot of sparks or slag, you are doing something wrong. The sparks from MIG are tiny bits of molten metal and they hurt A LOT. Protect yourself with heavy gloves and outer layers, and if it’s really bad there is a spray on product- Anti Spatter that can help. With MIG welding, the wrong settings can also cause a lot of sparks, so make sure you have the right settings, because you can’t anti spatter your way out of the wrong settings.
As you weld, you are directing a high voltage and high amperage arc of electricity at solid metal to melt it, the workpieces become extremely hot. Once metal cools from the red hot stage, hot metal looks the same as cold metal. It’s important to keep yourself safe, but also other users of the room. A soapstone note of “HOT at 6:30” could save your hands, and the hands of someone who comes in 15 minutes after you. Steel especially holds heat for longer than you think. If you are practicing, quench your pieces that are staying behind if possible. Leaving hot metal that is unlabeled is a serious issue and can be dealt with in a disciplinary manner.
Earplugs and respirators will be discussed during the orientation.
Surfaces can be contaminated with any number of chemicals. It’s important to clean them before you weld them. That being said, some of the chemicals people turn to can become quite hazardous when vaporised. BrakeKleen or ElectroWash are common choices and are very effective BUT they are really bad to weld with. Make sure you wait long enough for them to evaporate or clean them off thoroughly before you weld. There are not a lot of chemicals involved in welding, acetone can be used for surface prep. Again, wait for the acetone to evaporate! Always read the label and obey the instructions. If you need latex gloves, come get them from the machine shop.
Avoid cleaning chemicals that include chlorine. Vapourised chlorine is extremely hazardous to your health and the people around you, including those in the hallway who have no idea what you’re doing.
This is kind of a funny one, there are some common items you can have on your person that present a significant hazard while welding. Butane lighters are a big one, they are essentially a bomb in your pocket if a spark hits them. Leave them in your bag, and preferably outside of the room. Contact lenses are another, they will easily melt into your eyeball with a rogue spark. They can also trap chemicals between the lens and your eye so even if you are just doing surface prep for someone, you may want to consider wearing glasses that day. Synthetic fabrics are another kind of hidden hazard. They melt rather than burn which makes them hard to separate from your skin. It’s in your best interest to wear as much natural fiber clothing as possible, all the way down to your underwear and socks. In the end, it’s obviously personal preference and availability, but the closer you can get to all natural, the better.
Welding requires the following PPE items:
Optional PPE (may be required depending on what you are doing):