Today I Think I cracked the code.
First shot for the zink. Wait 10 seconds. 8 seconds flush 20 seconds rebound. Seemed pretty stable om 93'5 celsius through most of the shot. Test data and diagram Will follow and hopefully show that I am right.
One thing I have noticed is that if the flush is too short the temperature Will rise through the shot. If it is too long it Will Fall during the shot. 8 seconds seemed right.