I have a need to weld a cast iron part. What is the appropriat preheat/post heat temp. I was thinking around 600 deg. Am I close? The last time (about 10 years ago) I just put the part on top of the wood burning stove. Now I have an oven in the shop so I can use a little more control. Robert Ehrenberger Shelbyville, Mo. eforge at centurytel.net