This happened to me the other day and happened a couple of times to another bloke on our firm today. What's happening is, welding all day, same piece, over and over again, hundreds to do. All dialed in, welding away for 3 or 4 hours then suddenly the wells look like no gas. They look like honeycomb. Grind them out and re weld..same result. Cleaned tip, shroud etc, made sure no kinks in torch lead, check there's gas in bottle and listen for it at the shroud. Can hear it hissing. Turn regulator up, shroud houhis louder. Tried cleaning up the return clamp and attaching it up the piece itself instead of the table. Nothing worked. When it happened on me I messed with the settings and eventually it went ok but when it's happened today, we couldn't sese to get it going right. It started working fine again then about 2 hours later, same again. Didn't have time for much of a look then but there's still loads up weld. Any ideas what we can do/ what's causing it? Settings etc... Without trigger pulled... With trigger pulled.. These are the same settings we always use for these pieces and the same 2 blokes do them 99 percent of the time.