Galvanized Metal inside Smoker?

Discussion in 'Fridge/Freezer Builds' started by cowboycousie, May 13, 2015.

  1. cowboycousie

    cowboycousie Fire Starter

    Are the any issues to using galvanized metal in a fridge smoker?

    I need to wrap the cabinet where the door closes and pan the inside of the door where I removed the plastic shelves.

    The cabinet inside is porcelain, However I need to repair the hole where the shelve mounts were. 

    What could be used to seal these holes?


  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Big box stores sell aluminum flashing that will work.... It is a baked on some sort of coating....
  3. Galvanized is bad. The zinc coating releases chemicals when it hits a certain temp. I believe it's higher than what most smoke at but not worth the risk.
  4. I think galvanized is probably not as risky as many people here seem to think it is. I haven't seen any studies showing otherwise. If you weld on galvanized steel in a confined space, you can definitely suffer from some nasty symptoms, but if you eat a teeny tiny amount of residue that might come off the walls of a well seasoned smokehouse, you'll probably be well below the maximum safe limit. I think a good rule of thumb would be to minimize the amount of it and then coat it with vegetable oil and overheat to maybe 500 degrees for a while to drive the risk out of it.
  5. ak1

    ak1 Master of the Pit OTBS Member

    OK. Zinc(which is the galvanized coating on steel) melts at 787 degrees. No fumes there. It boils at 1665 degrees(all numbers fahrenheit). Is your smoker going to get anywhere near those temps.

    I work in a steel mill where I am near an open pot the size of a small bedroom filled with molten zinc. I've been there for 20 yrs and I spend 12hrs per shift within 20ft of this thing. I'm still alive and well. 
  6. Is there anything else added to the zinc that's used in making galvanized sheet metal or galvanized bolts? I wouldn't think there would be, but things like lead and cadmium really don't belong anywhere near food. I'm sure that lead is not in anything new.
  7. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Why use, or even consider zinc, when the possibility exists for problems and you are taking so much time to try and verify it will be safe to use ????

    Don't use it and all the discussion is moot.....
  8. Possibly saving money is one good reason for using or considering it. If somebody had some, they could save money by using it. And if it is safe, why not? Why be afraid of something for no good reason? The original question was, "Are there any issues to using galvanized metal in a fridge smoker?" The answer to the question is either yes or no. The possibility for problems exists with anything that's coated with anything. Fumes will cook off from any paint, glaze, or oxide if you get it hot enough, but we're not making blast furnaces. It's a legitimate question. Does anyone have a good reason for not using it?
  9. tropics

    tropics Smoking Guru SMF Premier Member ★ Lifetime Premier ★

    I believe it is known as Zinc Oxide Poisoning 

  10. sawinredneck

    sawinredneck Meat Mopper

    Id researched and researched this topic a while back as I'd inadvertently used a piece of galvanized for a heat baffle. We didn't die, so I checked into it more,
    If your smoker is hitting temps above 1400deg f, better not use it! I used a leftover piece to make a chimney extension, painted with high temp paint, if the paint bubbles, I might get concerned. But honestly, those of you worried about heat and zinc, you probably should quit smoking, you've got a better chance from your cigarette filter than you do from using it in your smoker due to the higher temps! I'll leave it at that.
  11. sawinredneck

    sawinredneck Meat Mopper

    I just noticed something else, those of you worried about zinc exposure probably should quit using a charcoal chimney! I was just noticing mine is galvanized steel! I'd bet there's a lot better chance of off gassing from that than anything in my cooking chamber.
  12. From a meat smoker? Have there been any documented cases of that? Or is that just an irrational fear?
  13. chef jimmyj

    chef jimmyj Smoking Guru Staff Member Moderator Group Lead OTBS Member

    This topic comes up every few months and the same, " Zinc is Bad ", posts, based on speculation, hearsay and paranoia, get added to the thread. We just don't make the kind of heat needed to vaporize Zinc in a smoker. Even if used in the Fire Box, the initial burn out and seasoning of the smoker would eliminate any further issues...JJ
  14. I don't know if anyone here has tried to weld galvanized steel it gives off a yellowish smoke and makes you pretty green around the gills. They don't manufacture BBQ's out of it for that reason. And yes both welding and grilling are a much higher heat. At smoking temps you might be OK but it's your gamble.
    Side note. An old welding trick for welding galvanized is to drink milk it supposed to coats the stomach. But again a gamble.
  15. sawinredneck

    sawinredneck Meat Mopper

    I've welded lots of galvanized metal, grind off what you can and go for a well ventilated area, no problems.
    But at what temps are you melting steel to make a seam? At what temps are you smoking meat?
    Let's be realistic about it, if high temp paint isn't coming off, neither is the zinc.
  16. That's just it, there is apparently no evidence that at smoking temps you won't be okay. This reminds me of the fear of pressure treated lumber. Some people are afraid to touch it. I've seen homemade smokehouses out here in the sticks made from pressure treated lumber and corrugated galvanized roofing or painted steel roofing. I've never heard of a single incident of anyone getting sick from them. I've even heard of baking the plating off cadmium plated refrigerator shelves by leaving them in a wood fire and then wirebrushing it off. Again, no reports of sickness from that.
  17. ak1

    ak1 Master of the Pit OTBS Member

    No, it's just zinc. Where I work we have another type called Galvalume which is Zinc & Aluminum.

    Thing is, if you're worried about zinc, then you should probably worry about the Weber grills which are chrome plated. Chromium isn't exactly healthy either.
  18. dirtsailor2003

    dirtsailor2003 Smoking Guru OTBS Member

    There are several resources that talk about galvanized metal and how it shouldn't be used when smoking meats or for food storage. One is this document:

    Then there is the NSF guide:

    Granted it only talks about food coming in direct contact. Wet, and or acid foods can leach the metals out of it.

    Now above it was mentioned that galvanizing only contains zinc or zinc and aluminum. That is false. Typical hot dip involves only zinc, but then there is also hot dip that contains aluminum (galfan). Electrolytic galvanizing can be straight zinc or can contain nickle, and there is also Galvalume which contains aluminum. My father in law who has been a chemist for 50 years doesn't recommend galvanized metal around the kitchen or anywhere that food prep is taking place.
  19. The first source said, "Cook food in smokers made of materials approved for contact with meat and poultry. Don't smoke foods in makeshift containers such as galvanized steel cans or other materials not intended for cooking. Chemical residue contamination can result." Is the inside of an old refrigerator approved for food contact? It sure wasn't intended for cooking.

    The second source said,

    "7.4.2 Zinc coated materials

    Galvanized materials and other zinc coated materials shall not be used on surfaces intended for direct food contact.

    7.5 Organic (non-metallic) coatings

    7.5.1 Direct food contact

    Paint and other organic coatings shall not be used on surfaces intended for direct contact with food, except where flouropolymer resin coatings (e.g, polytetrafluoroethylene) are specifically permitted for use under other NSF Standards."

    Does anyone know if the paints used in commercial smokers would pass this spec? Does anyone know if the paints used in old refrigerators would?
    Last edited: Aug 11, 2015
  20. ak1

    ak1 Master of the Pit OTBS Member

    Do you notice a common thread?.... Direct contact.

    Look, I posted facts about zinc. Whether one wants to use it or not, is a personal choice. Plain and simple, there are no issues with using galvanized fittings in a smoker. Not grate surfaces that are in direct contact, but screws and nuts are not an issue.

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