Craig D

Don't worry about the heat and a steel frame - very few steel frames are heat treated (none that I know of) and are usually made from a "normalized" steel and, if anything, the powder coat baking would help reduce any heat effected zones created during welding or brazing (which is 1,200, 1,700 or over 2,000 degrees F for silver or bronze brazing and welding). Tool steels are baked at 300-400 F for their heat treat and are more "brittle" than bike frames (higher temps == softer, more ductile/tougher steel).
Craig D

----- Original Message -----
From: Brian Engelen
To: 'Clark Ritchie' ; obra@list.obra.org
Sent: Tuesday, February 07, 2006 2:34 PM
Subject: Re: [OBRA Chat] Help - Rust on my Frame!

I'd do some checking before I powder coated a steel frame. First of all, my only experience is non-bicycle, structural steel frames for machine tools. A lot of heat is needed to get that powder paint to work correctly. Sometimes up to 475 degrees Fahrenheit. It's OK for non-precision soft steel parts. I'm not sure what this will do to a bike frame. My concern is related to heat treatment of the tubing and warping.

Brian