A common heat welding mistake is shown here: no radius at the base. The side of the groove was cut square, and without a radius at the bottom of the groove the weld will fail.

Straight Edge and Butt:

Groove Cut Too Deep:

Groove Cut Too Wide:

Contamination of Groove:

Pictured is another common error: a groove cut down to the substrate. When a groove is cut too deep, it can lead to failure.

Poor Power Source:

Poor Heat Setting:

Moving Too Fast:

Sudden Movement of the Welder:

Take care to keep the temperature levels consistent throughout the heat welding process. The picture shows scorching from too much heat, which can cause distortion of the urethane wear surface.

Adhesive Not Dry:

Moisture Condition in Slab:

Crowding One Side of the Groove:

Improper Weld Tip or Use of Tip:

Skiving Too Early or Too Late: