MIMF

I am about to make a 2nd bending iron (smaller diameter than my main iron) and I will be heating it with an electric charcoal ignitor. This has worked well enough for me but, I vaguely remember an old discussion about reducing the warm-up time and distributing the temp most evenly along the pipe by stuffing it with metal mesh.

I bought some stainless steel spiral scrubbers which would seem to fit the bill nicely. The only thing is, there was some talk in the old discussion around NOT using particular materials inside the pipe due to possible toxic offgassing. Was this related to galvanised steel? I can't remember the details and for safety's sake I hope someone can fill me in. I think I recall that pure copper spiral was a good choice but the stainless was very easy to find and copper, not so much.

Chris

Yes, I believe your memory is correct: heating galvanized iron pipe can cause toxic fumes from the galvanizing. Stainless steel should be safe, but copper or brass scouring pads would probably conduct the heat better.

The zinc galvanizing has to be vaporized to form zinc oxide which means it has to boil. The boiling point is over 1000º F so probably not a concern. Breathing zinc oxide causes zinc fever with flu like symptoms that can last 24 hours. This mainly a worry for welders.

You can find copper scrubbers in virtually every grocery store and Walmart across the land. They work great for this application.

Small clarification: I am only asking about the mesh or spiral filling I'm looking to put into the pipe. The pipe itself is iron as used in water filled radiator home heating systems. And, I've not yet found copper mesh locally, only stainless.

I don't know about toxicity from heating stainless steel but I suspect it is a non issue. I will say that it will not conduct heat nearly as well as copper. My hot pipe of the last 10 years is a chunk of heavy walled steel with a charcoal starter and it works great. My only complaint is that it takes a fair amount of time to heat up well enough to bend and even then there are hotter spots than others. When I need to bend something really tight, I stick a chunck of copper pipe in there and even thought the bending surface is much further away from the heating element, it heats much more evenly. Because of this, I intend to make an aluminum bending iron (when I get around to it).

I would hold off until you can find copper scrubbies if I were you.

David is correct about the temperatures needed to vaporize galvanizing. If you search for "brass wool" or "bronze wool" you will find it available from a number of sources. Google (or your other preferred search engine) is helpful.

To confirm the stainless-steel issue - I took a TIG welding class last year (that was fun!!) and learned that stainless steel is easier to weld in part because it doesn't conduct heat as well as aluminum and steel, so you're less likely to melt through it (something that isn't an issue for pros, but for students... )

Also, high-end stainless cookware like Calphalon and All-Clad has a conductive inner core of aluminum so it conducts heat more quickly and evenly.