Scientific Glassblowing training " Button " - used to make a button seal

The button differs from the olive in shape and size, slightly bigger than the "olive" with a central ridge used to make a button seal. Adjust the burner to give a cooler flame the same diameter as the tube.
Heat and compress the tube to form a ridge , heat either side of the ridge to widen the tube

Видео Scientific Glassblowing training " Button " - used to make a button seal канала johntheglass