I have my hot plate set at about 244C or 470F. I have no way to test the exact temp other than the adjusting knob’s markings. I have my home made irons on the hot plate preheated. It takes approximately three seconds to weld with a single application of the preheated iron on the fabrics to be welded. At this temperature the fabric will not burn or wilt in three seconds. After the three seconds I use a cold “iron” to press and smooth out the fabrics after the heat application.
Mike