Galvanised steel: problem, or problem solver?

Galvanised steel: problem, or problem solver?

Postby GUS » Sat Aug 31, 2013 8:38 pm

Seems there is a lot of consternation on the site with regards to using galvanised steel within smoking circles.

depending on what you read (here & other places) then choose to interpret, it is both safe AND unsafe to use for food smoking, no wonder i'm confused (& evidently many others across the internet).

There's clear sucking of teeth when it's mentioned, & on the flipside recommendations to use / purchase galv incinerator bins or buy galv steel professional smoke box / shack (of which i've witnessed both today here rootling through the archives.

So what is it? safe or Unsafe...

Surprisingly I landed on this bit of heresay which seemed pretty informative (maybe no if I probe further).
..................................
source: [url][http://chowhound.chow.com/topics/284991/url]

Question posed was safety of galv incinerator for use as a smoker... but to save time i've merely posted the 2 clear answers (from persons unknown, "someone random off the net")
..................................
Robert G Jun 7, 2006 12:52 AM
My research on the web and several MSDS sites, plus information gleaned from Raku glazers using Galvanized trash cans, indicates you would have to heat the Zinc above it's Boiling point to generate fumes. Not likely to happen in a smoker.
..................................
FlyFish May 5, 2006 08:39 AM
I work in the area of assessment of human health risk from exposure to unregulated hazardous waste sites. Galvanized products are coated with pure zinc, which is not one of the metals that we generally pay a lot of attention to because it's unusual to find health risks in the general population from exposure to zinc. Zinc is one of a number of metals that the body requires in trace quantities but which can become toxic if consumed in sufficient amounts. Excess zinc in the body can also be detrimental because it has the effect of stripping other beneficial trace metals (e.g., copper and calcium) before it itself becomes toxic.

Zinc melts at a relatively low temperature and I suspect that in your galvanized trash can smoker some zinc is vaporized and ends up on the surface of your food. This probably occurs at a much smaller rate after the smoker acquires the black coating you describe, which would have the effect of isolating the zinc coating.

All of that said, I strongly doubt you are exposing yourself to enough zinc to be concerned. As you may be aware, some people believe that relatively large doses of zinc protect against and/or cure the rhinoviruses that cause the common cold and similar diseases. If you regularly take zinc supplements for that or some other reason (and eat a lot of your own barbeque) there may be a small chance that the additional zinc from the smoker could be detrimental. Otherwise, I personally wouldn't be worried about it.
...............................................................................................................................

What is your take on this subject? galv steel is a rock solid cheap item (done properly) with potentially extensive lifespan & durability with pretty much zero maintenance,....

It's a favourite proven material to me (as farming stock) & strikes me as good material to stick on an outside wall as a smoker, would you use it as a liner / construction material then go over it with a different coating (that is an option in the galv hot dip trade) & would that be enough to allay fears?

coating used is a polyurethane format (not read up on it admittedly, however it's worth remembering p/u is very widely used withing the food & beverage industry ..& in refrigerators for panels etc.

I know cold smoke / hot smoke are poles apart, but so is a covering layer of smokey build up compared to a shiny new lump of galv!


Your input as ever is greatly appreciated.
confusing innit? :roll:
Mac's ProQ CSG devotee.
Founder member of "Cheese club" ...it's like "Fight Club" only cheesier

Avatar courtesy of Thad Cox https://twitter.com/LimitedFun http://limitedfun.tumblr.com/
User avatar
GUS
Registered Member
 
Posts: 600
Joined: Sun May 26, 2013 1:05 pm
Location: Cambridgeshire U.K.

Re: Galvanised steel: problem, or problem solver?

Postby RodinBangkok » Sat Aug 31, 2013 11:12 pm

I think the best way to take out personal opinion on questions like this is first to refer to known standards, then take the posts of others for what they're worth.
Here is a link to the NSF materials spec.

http://standards.nsf.org/apps/group_pub ... .php/3941/

From this you have a reference to standards and the use of galvanized.

For my 2 cents worth, if food comes in contact with the surface, that surface should not be galvanized.
I am the master of my fate:
I am the captain of my soul.
_____

Rod
RodinBangkok
Registered Member
 
Posts: 343
Joined: Wed Aug 13, 2008 7:55 am
Location: Bangkok, Thailand

Re: Galvanised steel: problem, or problem solver?

Postby GUS » Sun Sep 01, 2013 8:23 am

Thank's Rod.

Taking this down to the "inane" aspect (which H&S or sheer dumb-ass-ery can excel & still astound us with examples... " Not safe for DIRECT contact with food" ..no intention of nailing any product intended for use to the galvanized side of any galv product I may utilise within a design, ...that'd be a waste of food.

Therefore to cheap commodity materials such as "metclips" for heavy duty trellis as side supports for a food bearing tray (for example), or an 8mm steel hook on plate as a bearing section for a pole or to utilise as a hanging point are all fine, as no direct food contact is encountered.

I'm looking at what's available & laying around, like to try to build once / buy once / buy less / recycle.

Along the same line of thinking (via this document) therefore we should be wary of unsealed wood materials which encase the majority of home-made smokers, (i'd be more wary of the glue & waste used to produce O.S.B. type chipboards, marine ply's etc.

Not that I wish to poison family or friends, nor come a cropper to a slow build up of pollutants (enough of that in a cars tailpipe)!
Mac's ProQ CSG devotee.
Founder member of "Cheese club" ...it's like "Fight Club" only cheesier

Avatar courtesy of Thad Cox https://twitter.com/LimitedFun http://limitedfun.tumblr.com/
User avatar
GUS
Registered Member
 
Posts: 600
Joined: Sun May 26, 2013 1:05 pm
Location: Cambridgeshire U.K.

Re: Galvanised steel: problem, or problem solver?

Postby saucisson » Mon Sep 02, 2013 7:21 pm

My personal opinion is that it would be fine for a cold smoker, particularly if PU coated. However, because many folks use smokers for multiple purposes, and because even cold smokers can suffer from fire issues, forum policy is not to recommend galvanised steel.

Hope this clears things up :)
Curing is not an exact science... So it's not a sin to bin.

Great hams, from little acorns grow...
User avatar
saucisson
Site Admin
 
Posts: 6817
Joined: Sat Mar 04, 2006 8:46 pm
Location: Oxford UK

Re: Galvanised steel: problem, or problem solver?

Postby DiggingDogFarm » Wed Sep 04, 2013 5:30 am

Ah, the zinc galvanizing issue!!!!

It takes a lot of heat for it to become a problem.

The noxious fumes generated are zinc oxide, zinc must be heated above 1665 degrees F to vaporize, combine with oxygen and form zinc oxide.

The melting point of zinc is 787 degrees F. When I worked in a foundry the zinc for hot dipped galvanizing was kept at right around 800 degrees F, no irritating fumes from that!!

FWIW, Here's a video of a hot-dipped galvanizing zinc bath, much the same as it was in the foundry.
As you can see, there's no special respiratory protection required.

http://www.youtube.com/watch?v=c2J07n5hSbs

People will listen to what they want to hear, people will believe what they want to believe.

~Martin
~Martin
Unsupervised rebellious radical agrarian experimenter, minimalist penny-pincher, self-reliant homesteader and adventurous cook. Crotchety cantankerous terse curmudgeon, non-conformist and contrarian who questions everything!
User avatar
DiggingDogFarm
Registered Member
 
Posts: 446
Joined: Wed Jan 25, 2012 5:38 am
Location: Finger Lakes Region of New York State


Return to Smoking and Barbecuing

Who is online

Users browsing this forum: Bing [Bot] and 2 guests