Hi folks, quick question about galvanised metal...

Would it be safe for me to set my brake drum forge into a sheet of galvanised metal so there's a surface around the brake drum for me to rest the butt of my work on? At the minute I have a few stacks of bricks around the drum but it's not ideal and it's still quite a balancing act. I've heard about the dangers of using galvanised metal but I constantly see metal garden bin incinerators that are galvanised, which makes me wonder if a sheet of galvanised metal would be safe for the job.

Obviously I won't do it if there's the slightest risk, but I can't help thinking that if there's not actually going to be any hot coals on the galvanised metal and they're contained within the brake drum, then surely the sheet wouldn't get as hot as a galvanised incinerator?!

Any words of wisdom?...

Personally, I would not use galvanized for any part of a forge, or anywhere near a fire. I have seen stores selling galvanized fire rings for camp-type fires, but I would not risk being around a fire in or near a galvanized surface.

Pickle and wash the galvanized metal to remove the zinc. Muriatic acid is quick but more dangerous, vinegar is slow but safer. Neutralize with ammonia or baking soda, rinse well with water.

Phil

You sir are a genius. Is there anything vinegar can't do?!

So far I haven't figured out how to get vinegar to tie my boots. That's about it.

You will be fine leaving the metal galvanized. The fire in your forge is contained in the drum and the heat being radiated through the drum is nowhere near enough to melt the galvanize coating. You could look up the melting point of galvanize and if you will have enough heat to melt it then be cautious.

It's actually not the melting point (around 500 F), but the boiling point (around 900F) where fumes form, here's a good article. :

http://www.theodoregray.com/periodictable/ZincSafety.html

Note that simple brazing creates fumes. I braze dril-tec with its brass matrix onto horseshoes in the forge and get the white zinc oxide coating the front of the forge. Beats useing a torch where I'm directly over the brazing.

It's actually not the melting point (around 500 F), but the boiling point (around 900F) where fumes form,

You have C and F mixed up. Zinc melts at 419 C / 787 F and boils at 907 C / 1664 F. You are correct that melting is ok just boiling is bad. Galvanize dip tanks are about 800 F .
http://www.chemicale...lements/zn.html

There are already fumes before zinc melts. Double check the phase diagrams. Zinc sublimates at a lower temperature than it melts.

Phil

I would stay away from anyhting coated with zinc. You may not be welding on it now but in the future, down the road when it is covered with coal dust and dirt, you may forget and try to srike an arc. Zinc fumes are bad stuff iformation below taken from an MSDS for Zinc:

"Inhalation: Inhalation of zinc dust or fumes may cause respiratory tract and mucous membrane irritation with cough and chest
pain. It can also cause "metal fume fever", a flu-like condition characterized appearance of chills, headached fever, maliase,
fatigue, sweating, extreme thirst, aches in the legs and chest, and difficulty in breathing. A sweet taste may also be be present
in metal fume fever, as well as a dry throat, aches, nausea, and vomiting, and pale grey cyanosis."

I realise blacksmithing may be "sweet" but this is not the way to taste it.