Welding is another of Roger's common activities. Here he welds a new trailer hitch into place on a truck. In this type of welding, called arc welding, the welding rod completes a circuit with the base material, generating temperatures around 1200º F and extraordinarily bright light. The light is so bright, in fact, and produces such intense ultraviolet rays, that it can burn the retinas and cause serious eye damage. Due to this intense light, heavy, dark eye protection must be worn. Even looking through a camera and wearing dark green glasses, the light was too bright for more than a few seconds' exposure. I was instructed not to get too close, because if a stray spark hit my lens it would melt and fuse instantly. However, Roger let those same sparks bounce off his arms like they were gnats. truck. In this type of welding, called arc welding, the welding rod completes a circuit with the base material, generating temperatures around 1200º F and extraordinarily bright light. The light is so bright, in fact, and produces such intense ultraviolet rays, that it can burn the retinas and cause serious eye damage. Due to this intense light, heavy, dark eye protection must be worn. Even looking through a camera and wearing dark green glasses, the light was too bright for more than a few seconds' exposure. I was instructed not to get too close, because if a stray spark hit my lens it would melt and fuse instantly. However, Roger let those same sparks bounce off his arms like they were gnats.