, Tognar runs their base repair irons at 500 to 550 F to melt their P-tex (high density polyethylene) repair sticks.
However, from http://www.sdplastics.com/hdpesheet.html
, the melting point of both high and low density polyethylene (and everything inbetween) is in the 250 – 260 F range.
The reason for this discrepancy is because if you run the iron at exactly (or only slightly above) the melting temperature, the P-tex would either never get up to the melting temp, or would take an extremely long time to do so, and thus heat up much of the inside of the ski while waiting for the surface of the base to get up to temperature.
Not only would this be slow, but it would increase the possibility of damage to internal structural elements, glues, etc.
Tom / PM