I got nothing to add to the original post but this did resurrect an old memory buried deep in my brain. When I was a kid in the 70s i can remember sitting with dad in the stands at EWS and every now and then Id see that distinctive blue glow and know someone in the pits was having something welded on their race car. I didnt understand the concept of welding yet, but I knew someone was having something welded. Its funny the random things you remember. Thanks for waking up that pleasant moment from almost 50 years ago.