Mailbox thingy

It's a fair question, it seems to me. I've been wondering about this recently too, having recently gotten my first smoker (a Masterbuilt electric), and having now done a "mailbox mod", except using a toolbox.

The most common topic on the safety front is the galvanizing of the mailbox steel (it seems like pretty much all steel mailboxes are galvanized, at least from my recent searching). Overheating zinc, such as if you're welding it, can produce really bad fumes.

The counter-argument, if you will, is typically that the inside of the mailbox should see pretty-low temperatures. The wood pellets/sawdust should be smoldering, not burning with a flame. So hopefully the temperature in there isn't actually very high.

I considered using my Weber Smokey Joe as my "mailbox". It uses a high-temperature finish, meant for use with charcoal and food, so they must have selected something food-safe at those temps.

I opted, instead, to use a powder-coated toolbox. I admittedly don't know what its coating will do at high temps. But my hope is that it's safer than galvanized steel. And I light the pellets with the tray out on the ground, then blow out the flame, and put it in the toolbox, so it shouldn't be seeing flame-type temperatures. When smoking, it definitely gets warm/hot, I wouldn't want to keep my hand on it comfortably. But I'd hazard a guess that maybe the top is around 150F or so, maybe less? I haven't tried to measure it, but I can touch it.

If I wanted, I could paint the inside of the toolbox with high-temp grill paint, to at least put a high-temperature-safe coating on the inside. Optionally, before that, I could torch the inside of the toolbox, to burn off most of the powder coating. Or if I had a sandblaster (I don't), I could just blast it off.

Merely my opinion, but from "safest" to "riskiest", the options seem, to me, like this:

- Use an inexpensive charcoal grill as your "mailbox". Made for food and very high temperatures.

- Use something else, like a toolbox, a popcorn tin (another solution from a user here), etc. I don't know how these coatings react to elevated temperatures.

- Use a mailbox. Simple, proven approach, but most likely galvanized, which brings some risk.

A grill may already include an adjustable intake vent, which is a nice feature. But you likely have to mount your ducting to a curved surface, and if you mount it on the top of the grill, then you'll move your ducting every time you remove the grill's lid.

On my toolbox, the ducting is still attached to the base of the toolbox, so it doesn't move when I open the lid.

Most people seem to get good results with their mailbox mods, and an AMNPS tray. So far, I've been having issues with keeping the pellets lit for more than several hours in my toolbox mod. But I'm working on trying to figure that out.

I've only read a little bit about the cold smoker add-on. I think I've seen some mention of people adding a means to reduce the voltage going to its heater, I believe to burn the chips more slowly. But in terms of cost, it's roughly the same as a mailbox + AMNPS tray, and it should be simple.

In terms of materials, the only other thing I did for my "mailbox mod" was to use aluminum duct elbows, and aluminum 3" flexible ducting. Rather than the galvanized versions stocked in the stores near me. The big-box stores may be able to ship aluminum versions to the store near you for free. Galvanized ducting should stay even cooler than the "mailbox" itself, but I figured if I was avoiding galvanizing in the box itself, I should stick with the plan and also avoid it in the ducting.

I used a food-grade popcorn tin. Lots of advantages over using a mailbox: there is zero issue with anything that is not food grade; it is cheaper than a mailbox; and it is larger volume which means you get more creosote condensation within the can (a good thing). Here is the post I made about how I built

Mailbox (Popcorn) Mod (with a small twist)

I had a bunch of these lying around from various Christmas gifts we've received over the years, but I found several sources where you can buy them for about $12, much cheaper than any mailbox I could find (even at Home Depot). I provided a link to one tin can vendor in that link above.

johnmeyer, I think the popcorn tin approach is interesting. And if I had one just sitting around, I'd try it at the moment, to see if it would help keep my pellets burning longer, vs what I'm getting in my toolbox :)

But I think the "there is zero issue with anything that is not food grade" statement may be slightly broad. It's intended to hold food, obviously. But at room temperature.

A plastic tupperware-type container is food-grade. But if I put it on my grill, and cook my food in it, clearly I'm going to have a problem (an exaggerated example, certainly).

In my opinion, the only way to say that a certain container is completely safe for this use is if it's meant for food, *and* high temperatures. Like a little charcoal grill, as an obvious example. Or something that's using a material that's "inherently" safe, like an uncoated stainless-steel box.

A cheap stainless-steel pot & lid might actually meet these criteria nicely. Stainless is difficult to drill/cut, unfortunately. But they're common, cheap, and meant for food, as well as high temperatures.

An aluminum pot would be easier to modify. Heck, this aluminum one is $14, not sure if it's big enough to hold a 5x8 AMNPS tray, but if it isn't, maybe there's something else that could hold one:

RedOctobyr said:

johnmeyer, I think the popcorn tin approach is interesting. And if I had one just sitting around, I'd try it at the moment, to see if it would help keep my pellets burning longer, vs what I'm getting in my toolbox :)

But I think the "there is zero issue with anything that is not food grade" statement may be slightly broad. It's intended to hold food, obviously. But at room temperature.

A plastic tupperware-type container is food-grade. But if I put it on my grill, and cook my food in it, clearly I'm going to have a problem (an exaggerated example, certainly).

In my opinion, the only way to say that a certain container is completely safe for this use is if it's meant for food, *and* high temperatures. Like a little charcoal grill, as an obvious example. Or something that's using a material that's "inherently" safe, like an uncoated stainless-steel box.

A cheap stainless-steel pot & lid might actually meet these criteria nicely. Stainless is difficult to drill/cut, unfortunately. But they're common, cheap, and meant for food, as well as high temperatures.

An aluminum pot would be easier to modify. Heck, this aluminum one is $14, not sure if it's big enough to hold a 5x8 AMNPS tray, but if it isn't, maybe there's something else that could hold one:
https://www.amazon.com/IMUSA-Aluminum-Handle-8-Quart-Silver/dp/B003ASZY7S/ref=sr_1_6?ie=UTF8

Click to expand...

I have a cheap aluminum pot that has a lid that fits the pot securely instead of just sitting on the pot. If the pot has legs and holes under the amnps in the bottom of the pot that would appear to bring air straight up to the lid with a hole in it or top side by the lid.
-Kurt

RedOctobyr said:

 
johnmeyer, I think the popcorn tin approach is interesting. And if I had one just sitting around, I'd try it at the moment, to see if it would help keep my pellets burning longer, vs what I'm getting in my toolbox :)

But I think the "there is zero issue with anything that is not food grade" statement may be slightly broad. It's intended to hold food, obviously. But at room temperature.

A plastic tupperware-type container is food-grade. But if I put it on my grill, and cook my food in it, clearly I'm going to have a problem (an exaggerated example, certainly).

Click to expand...

The popcorn cans are made of tinplate (tin-coated steel) which has been used for food storage for centuries. Unlike plastic, tin and steel are totally stable at temperatures used for cooking and certainly at the relatively low temperatures inside a typical mailbox mod (less than oven temperatures). If you research the subject, you will find more concern about contact with heated aluminum (some junk science suggests that it contributes to Alzheimers) than with tin. Of course if you look hard enough, you will find some study, somewhere, suggesting that every single substance you cook with may cause some problem (cast iron puts iron in the food; aluminum causes dementia; stainless steel contains chromium and nickel both of which are highly toxic, etc.).

While I would certainly avoid plastic, and I would not cook with lead**, most other materials that are used for any type of food storage are fine when heated. This actually does include a whole host of non-metalic cooking items, including the now-ubiquitous silicone scrapers and spoons, and Teflon cookware.

As for your problem getting the AMNPS to stay lit, most posts on this problem suggest that, when inside a mailbox mod you need to look at two things: the size and number of your mailbox air inlet holes, and the height of the AMNPS off the bottom of your mailbox. The little ridges on the bottom of the AMNPS don't get it high enough off the bottom to permit good air circulation. If you can find four 1" (or longer) small machine screws that fit into the mesh, just insert one into a hole near each corner and then use a nut on the top and bottom to create a simple standoff. There are several dozen posts in this forum showing how to do this.

** Don't laugh about cooking with lead. It was used to seal canned goods back in the 1800s and there is a famous story of a crew stranded in the Arctic who went mad and ended up doing crazy things that ended up killing them all, because they heated their food in the lead-sealed tin cans (the lead was the problem, not the tin). Here's one version of the story: Canned Food Sealed Icemen's Fate