Marking will be done upon receipt of the stainless materials in our warehouse and prior to fabrication, so the heat should not be an issue. I'm hoping to either confirm or contradict a statement made to me that SHARPIE markers cause cracks in stainless.
Can't imagine why that would be a concern...Sharpies contain organic solvents that are innocuous on stainless steel (butanol, propanol, acetone compounds...). To my knowledge they do not contain chlorides or other compounds that would be reactive or deleterious to stainless steel.
I've disassembled a modest number of used marine exhaust risers that were fabricated and assembled with Sharpie marks. I'm not prepared to say it doesn't happen, but I've never correlated a crack with a Sharpie mark.
That said, the more traditional way of identifying alloys in inventory is color coding with blotches of spray paint applied to bar ends or sheet edges.
Yes, Standard Sharpie markers can and do cause cause problems when used on SS and Nickel alloys.
Our welding procedure specifically prohibit the use of markers unless they are specifically marked as low chloride and/or low sufphur.
I copied my reply to thread794-264571
The use of chalk as posted above carries some caveats in that some of the lumber marking chalks have very high chlorides and some high sulphur. There is a metal marking chalk or you might want to go the old fashion way and use soapstone.
Here are some Low Chloride Markers as well as some Low Sulphur ones for Nickel Alloys. A lot of the Low Chloride markers are also Low Sulphur.
I haven't checked one lately, but in the past I found black Sharpies to be fine. DO NOT use other colors, many of them contain lots of things that could damage SS.
Take one, crush it, open it, and put it into a beaker of DI water. Heat in a microwave for a while and then let it cool. Do a Cl analysis on the water.
