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Discussion in 'Masterbuilt Electric Smoker (MES) Owners' started by inkjunkie, Dec 21, 2014.
Safe to use a galvanized mailbox when doing the "mailbox mod"?
Never mind....found my answer......No....
For anyone else that doesn't know. It's is NOT ok to use galvanized metal when working with food. When galanized metal is heated, it gives off toxic fumes.
You would think I would have known this from playing with a welder....duhhhh...some days I think I would forget my butt if it were not attached...
You can always remove the galvanized coating but it's probably easier to return that one and buy a non-galvanized one.
The one in our shed was galvanized, I am waiting on an aluminum one to show up...
I know this is an old thread and topic, but if someone wants to avoid using galvanized metal, what are folks using? Virtually all the cheap mailboxes are galvanized steel and I can't find any cheap aluminum ones. I did see the popcorn tin. Other thoughts on what to use to avoid the galvanized steel?
The zinc in galvanized steel melts at about 900°F and vaporizes at about 1650°F. I would not use it in the interior of a smoker, but I seriously doubt that an AMNPS will give off enough heat to create a health hazard.
I have read different things about the safe temperatures of zinc. In the below link, for example, it says temps of about 390 degrees Fahrenheit start to cause peeling of the zinc. My goal is not to debate the safety at this juncture but simply to find a solution that doesn't involve galvanizing or other potentially toxic substances. Thanks.
I cannot see where a mailbox mod would ever get the inside of the mailbox hot enough for any coating to be an issue. After I blow mine out, I pick my pellet tray up with my bare hands! No I'm not made of teflon, but the heat is only in a small concentrated area and it's just a glowing pellet ember, not an actual fire or burning charcoal. Truth be told I did an experiment some time back where I used a cardboard box for a mock up of a mailbox mod to see if I could get the air flow to go downhill into a main smoker chamber. In all fairness I did sit the pellet tray on a metal container top, but that was indirect contact with the cardboard. My point is the heat inside the closed "cardboard mailbox" simulation did not even char the cardboard, much less get warm or hot.
If it's not hot enough to burn the cardboard, I just don't see it being hot enough to off gas anything from a galvanized mailbox. Photos of the cardboard mailbox mod downflow test are in this thread:
Most of the time the pellet tray will smolder, and not be an issue.
However, I have had my tray combust and start burning in lieu of smoldering.
This has only happened once with me, but it can and will happen at some point in time.
It was more than enough fire and heat to be an issue, if I would have had a galvanized box.
Don't chance the health of your family and/or yourself for the hassle of not procuring an aluminum box.
Huge props on your experiment! The issue I have is trying to find out how safe the mod is. To your point, it does not get above 450 degrees or you would have had ignition in your test box. But, unfortunately, i called the galvanized manufacturers association I referenced above, and they could not give me a real clear answer about the temperature at which zinc fumes would start to form. Their article references 392 degrees where flaking of the zinc coating starts to occur, which is not good for smoking purposes, but I have also read anecdotal info suggesting as little as 200 degrees starts to release funny odors, if not outright zinc fumes. And a whole lot of folks are quick to jump in with the melting point of zinc which, for my concerns, is not particularly relevant. Since it's very difficult to get good scientific/medical data on safe temps, I am reluctant to go down this path. And I know others might chime in and say smoking food is dangerous, cooking with stainless steel is dangerous, etc., but everyone needs to pick and choose which risk tradeoff they are willing to make. In my case, if I can find a solution that minimizes this risk at a low cost, why not do it?
You know you could take a propane weed burner and then "burn" off the galvanized coating. Once it has burned enough to give up all the off gas, just sand the outside a little and hit with high temp paint. I would not worry about the inside after burning, just the outside for looks.
Also there is no reason you cannot get some raw sheet steel or raw aluminum and bend and rivet your own metal box with a door. It does not have to be heavy gauge, just enough to handle the weight of the tray and pellets.
Oh, and to throw one more thing into the mix. 99% of the people I've seen that talk about not using galvanized mailboxes have galvanized duct piping connecting the mailbox to the smoker. And I don't recall one post about either being a problem in the real world. It seems to only be in hypothetical questions (and the galvanized manufacturers assoc is probably just covering themselves as I doubt they have any engineering data on mailboxes for smokers).
And if the pellets are re-igniting, there is wind blowing in the holes and fanning the fire (ie, too much air flow). The most simple damper I've seen is one of those magnetic refrigerator stickers that you can slide around to block parts of the air holes (and that will not work on aluminum).