Burn-through
Burn-through turns up in 2 fields: welding, geosynthetics. Here is what it means to the people in each one.
Burn-through in welding
A hole melted through the root of a weld where the molten metal fell out.
Local collapse of the weld pool that melts completely through the root or a thin wall, leaving a hole or a sagging drop on the back side. It comes from too much current, too wide a root opening, a knife-edge land or lingering in one spot. Burn-throughs are repaired by grinding back to sound metal and rewelding, and they are a common way to fail a root bend or radiograph.
"Burn-through at four o'clock, grind it back to clean metal and bridge it with a couple of quick dabs."
Burn-through in geosynthetics
Hole or severe thinning in a geomembrane where a welder ran too hot or stopped on the sheet.
A wedge welder that stalls, or an extrusion gun that lingers, can melt through the sheet or thin it so much the area is useless. Burn-throughs are marked, cut out and patched, and the cause, usually a speed problem or a wrong setting, goes on the seam log. They are most common at the start and end of seams and on thin sheet in hot weather.
"Wedge stalled on the slope and left a burn-through, mark it for a patch and redo the trial weld."