RGS 20 - It took 2 1/2 hours to form the door sheet. The sheet was preheated for a couple of hours with propane heaters so it was hot enough for the guys to cook hamburgers on for lunch just prior to the start of flanging. After the door hole is flanged we will weld the door hole ring to the sheet and then have it normalized. The backhead sheet will then be fitted over the door ring. I prefer convex flanged corners in the firebox. The square corner on the outside is not an issue. The job came out as good as we have done. Part of the secret was having more hammer men, particularly at the end when you are tired from swinging at a nasty unnatural angle. Additionally, we have a really great bunch of young guys who do fine work - 22 Feb 2008 Linn W. Moedinger.