Mailbox (Popcorn) Mod (with a small twist)

Discussion in 'Electric Smokers' started by johnmeyer, Feb 4, 2017.

  1. johnmeyer

    johnmeyer Smoking Fanatic

    Two minor new ideas.

    1. Using a popcorn can. It's a nice size, and totally free (see my later post for where you can buy tins for under $12, if you don't want to spend $40 on gourmet mail-order popcorn and then use the "leftover" tin).

    2. Using aluminum mesh inside the duct in order to trap more creosote (click on my "later post" link above to see a much better alternative for filtering material than what I present below in this initial post).

    There are many reasons to use the "mailbox mod," but for me, I want to improve the quality of the smoke that I get from the AMNPS.

    The pictures should tell the story. I drilled four holes at four points of the compass around the bottom sides of the can.

    Above: the main components.

    Above: The aluminum mesh inside the duct. I used mesh sold as a lint trap.

    Above: All set to go (AMNPS lit)

    Above: Smokin' time.

    I originally was going to use a long piece of duct between the can and MES, but after I got it home and cut it to length, I realized the inside was lined with plastic. Oops! I'll have to add the long duct at a later time.

    Smoking tri-tip for tomorrow's game right now. So far, so good.
    Last edited: May 13, 2017
  2. crankybuzzard

    crankybuzzard Smoking Guru Staff Member Moderator OTBS Member SMF Premier Member

    I like this! Very innovative!
  3. smokinal

    smokinal Smoking Guru Staff Member Moderator OTBS Member ★ Lifetime Premier ★

    I like it too, it opens up a bunch of possibilities.

    Especially since metal mailboxes are getting harder to find.

  4. dr k

    dr k Master of the Pit

    Looks good. I think you mentioned the mesh before but I didn't see the visual till now. I picked up a couple more 2'x3" snap together aluminum vent pipe yesterday but can never find a y fitting to make a venturi for cold smoking. I saw 3" caps to plug the bottom chip loader opening of the smoker when done adding smoke to make it a draftless oven. I cut the chip loader portion that sticks in the smoker off and made a plug with a handle instead before I saw the caps. I saw a 90 degree saddle fitting that has a nice rounded flange that would work perfectly on the top of a rounded mailbox or top side of your popcorn can. Hopefully you won't get condensation dripping on the amnps durung these colder months. If I had a decent container I would do the same and save a few bucks to spend on pipe and fittings. On my mes gen 1 40 I plugged the back grease drain hole with a paper towel to keep all air going through the mailbox mod and foiled over the bottom drip pan and hole. I don't get pools of juice on the bottom pan to need a drain. When no smoke is needed, a folded dedicated smoker towel over the closed top vent (as much as possible with therm cables going in) and the plugged loader hole really cuts down temp swings. The pics below is the plug from the loader.

  5. johnmeyer

    johnmeyer Smoking Fanatic

    One question: is it a good idea to hold the smoke in the smoker? I've done a lot of reading, and there seems to be a school of thought that more air/smoke exchange is better, and that one of the problems with the MES is that it exchanges the air/smoke at about 1/100 the rate of a more traditional smoking device. This leads to smoke flavor problems.

    However, since I am not an expert, I don't know if this is true.

    Interesting point about having condensation dripping back on the AMNPS during cold weather. I would think that would be a problem with the mailbox mod, as well as my minor variation on that design. I haven't heard anyone talk about that. I certainly did not see any moisture on the lid when I removed it a few times during my initial seasoning test run.

    BTW, the tri-tip turned out great, so I am encouraged by the results. I think I have just the right amount of air going through with just my four holes. I had done quite a bit of work with previous attempts at this, and was pretty sure this was going to be just about the right amount of air. I did get a few backdrafts when it was really windy (smoke coming out of the intake holes for 1-2 seconds), but I don't think there is much that can be done about that, and I don't think it significantly affected the amount of smoke getting through the smoker.

    Having the tray sit halfway up in the can is a little higher-up than I would have wanted, but it sure make the AMNPS smoke better than it ever did inside the MES. It took about 2.5 hours instead of 3.0 hours to burn through the first row of pellets. It would be interesting to have a gas chromatograph to analyze the components of the smoke delivered when the burning is done in the MES vs. these external devices. Having sufficient oxygen should make a positive difference, but there is no way to know for sure without measurement.

    If someone gives me some popcorn for Christmas this year, and sends me a BIG can, I may use that instead. I sense that bigger is probably better.
  6. dr k

    dr k Master of the Pit

    When I disconnect the mailbox mod from the chip loader hole when I'm done appying smoke, the residual smoke in the smoker evacuates. Then when the smoker is cleared of smoke I plug it up as a draftless oven.

    My mailbox drips at the bottom edges where the sides attach. The arched top of the mailbox is hottest and the condesation forms on the sides and bottom so your probably good, keeping drips off of the amnps.

    You don't have an issue with air, burning a row at that rate. At least refrigerator magnets come in handy to help regulate if needed.

    The tri tip sounds great. I can't find that cut of bottom sirloin here in central IL. It's everywhere out west.
  7. johnmeyer

    johnmeyer Smoking Fanatic

    Ah, I understand now. The smoke is gone before you plug it up. Neat idea.

    As far as drips go, one nice thing about using these cans is that they are sealed at the bottom, so they will actually hold water. I drilled the holes on the side about 1/2" up from the bottom, so if anything accumulates on the bottom, it won't leak out.

    I had thought of all sorts of complicated louvers and other things to regulate the air flow, if that turned out to be needed. Your magnet idea is brilliant, especially since this tin is magnetic. Even if it was aluminum, I could simply use one magnet on each side. So that's another great idea. Thanks!
  8. johnmeyer

    johnmeyer Smoking Fanatic

    I am still experimenting with filter material to put into the conduit. You may have noticed in my initial pictures that I used some aluminum mesh similar to window screen material. It is sold by Home Depot for trapping lint. However, it has almost no surface area and did virtually nothing. After each smoke it was barely dirty, whereas the inside of the can was covered with thick goo.

    The reason I used the filter is that I was not eager to add twenty feet of conduit between my external smoking source and the smoker. I am not convinced this is helpful or needed, and even if it provides some benefits, it is a brute-force approach to the problem with a lot of downsides (cost, space, storage, etc.). I certainly have not seen it used in commercial "offset" smokers that separate the smoke box from the food chamber, nor do I remember ever seeing it in pictures of smoking competitions. If this were a great thing, all the pros would be using it.

    However, I do like the idea of making the smoke as clean and as "sweet" as possible, so I kept thinking about other filter material that might work better.

    Yesterday I \purchased some 3m Scotch-Brite stainless steel scrubbers, and they look to be exactly what I was looking for. I have pulled them apart to open them up and will stuff one of them into the conduit for my next smoke.

    Out of the package it is really dense, but when you pull it apart, it becomes much more open, and air flows quite freely through it. As you can see, the material is actually made of flattened steel, so the surface area is enormous compared to what I was using before. I'll report my findings when I've had a chance to use this new addition.

    If this does work, the neat thing about it is that this stuff is dirt cheap, and for those without ultrasonic cleaners, you could afford to just throw out the filter when it gets too foul.
  9. masonsjax

    masonsjax Fire Starter

    IME, those SS scrubbies have a lot of oil on them from the manufacturing process. I would suggest cleaning them thoroughly, maybe with minieral spirits or similar, before using them with food. I'm anxious to see how the experiment goes.
  10. dr k

    dr k Master of the Pit

    Hi John,
    Creosote condenses as low as 250f. People with the smoke daddy like cheese master mr T has a sloppy tarry container of sludge and smoke gets lighter/dryer as it gets piped closer to the product chamber. My mailbox is sticky and less as it gets closer to the product chamber. Its all about the outside temp. I've seen many bacon, lox and ham curing/smoking vids on How It's Made that all have had piped in smoke. Nothing to take up space in the product chamber. If you use wood/coal to heat/flavor your smoke then I prefer having a separate grill to burn down wood and shovel to the fire box smoker until you can add splits etc. And keep shoveling mostly burnt low smoking high heat embers in an offset. When it comes to propane/electric heat source there's no need to cook the smoke generator with the food. Get it out and operate it separately. Don't open the smoker, open the door to the smoke generator in the mod. That's why competitors don't use elec/gas as much and the unimportant smoke ring. I'm confident that the best flavor is from coals of any type at 650-750f which is low smoke will be the best flavor you can get from what your burning. Otherwise in elec/gas get it out of the smoker and pipe it in. I have issues with safety putting smoke generators in an mes because its not designed for it. So I get it out and have it in the intake draft that is safer and more reliable. If it fails which hasnt happened then I dont have to open my smoker. If you want to compete, don't bring a watt burner and shovel in coals that will alway be TBS. Or pipe in to a mes with an after market smoke generator.
  11. johnmeyer

    johnmeyer Smoking Fanatic

    Interesting. I didn't know that. I'll put them in my ultrasonic cleaner for a few minutes. Thanks!
  12. johnmeyer

    johnmeyer Smoking Fanatic

    Two quick updates.

    First of all, the Scotch-Rite pads worked really, really well as filters. Unlike the little lint filters, which did nothing, these filled up with gunk. I may try adding a second pad.

    Second of all, I found a really cheap source for popcorn tins:

    The prices are incredibly good. The first tin on the page I linked to is exactly what I have. I like it because I can store it in my smoker, but if I were to do this again, I'd probably pay $3 more ($14.99) and get the 6.5 gallon tin instead of the 3.5 gallon tin. Why? Well, my AMNPS will not fit all the way to the bottom of my tin, because the tin tapers from 10.25 down to 9.0 inches, and the AMNPS is about 9.5 inches from one corner to the other. The bigger tin would let me place the AMNPS on the bottom (although I'd have to elevate it with some feet in order to get good air flow underneath.

    The other reason a larger tin would be better is that it would provide more surface area for condensation.

    The key thing is this: you can't find a cheaper alternative. This is definitely cheaper than any mailbox that I was able to find.
    Last edited: Mar 20, 2017
  13. tallbm

    tallbm Master of the Pit

    Interesting!  I'd love to see a picture of the scrubbie filter and see how much gunk it has caught.

    Also, do you have any plans to do a look and taste test on something simple like chicken.  A smoke with the filter and one without to see what the meat looks and tastes like after a day in the fridge or so?
  14. dr k

    dr k Master of the Pit

    Try Mr t's method. Put bags of ice on anything that can support it. Superfied, condesified! Don't ask! It's local ad. And it's not a pizza.
  15. johnmeyer

    johnmeyer Smoking Fanatic

    I posted a pic of the filter in my post above (click to go there).

    Here's a link to the product on Amazon:

    3M Scotch-Brite Stainless Steel Scouring Pad

    You can get it much cheaper in the stores, and it is available elsewhere.

    I don't have any plans to do before & after tests, because I don't smoke that frequently (a few times a month). I can tell you, for sure, that this external smoking mod has made a HUGE difference in the taste of all my smokes. I will never do another smoke without it.

    As for the filter, I might try adding a second or third one, just to see how much gunk ends up on each succeeding filter. I'll certainly post here if I have something new to report.
  16. tallbm

    tallbm Master of the Pit

    Thanks for the info.  I didn't word my question too clearly lol.  What I was wondering is if you could post a picture of the gunked up filter.  Inquiring minds want to know :D

    I would possibly be willing to do a with filter vs no filter test in my setup.... some day.  I gotta find time to finish my freaking Heatermeter project box, wire everything up in, then rewire my MES before I do a smoke.  Well I dont' have to wait but I am finding it hard to go back to the MES stock controller after using an Auber PID on the MES I rewired and setup as a gift for my mother hahahaha.  I'm now ruined by PIDS :D
  17. johnmeyer

    johnmeyer Smoking Fanatic

    Yes, I'll post a pic of the filter before & after. It will be an interesting photographic challenge to show the difference.

    As an EE, I'm always interested in controllers. However, even though I've read a lot of the PID posts, I'm not entirely clear as to whether this would help me produce better food. Yes, I know that my MES controller lets the temperature go up and down a lot. I actually think it was designed that way on purpose in order to provide a longer period of time for the heater to ignite the chips. If you use a proportional control that modulates the heat input as you get close to the set point, you may achieve absolutely constant temperature, but I'm not sure you would get good smoke.

    Of course now that I have my "mod," I no longer have to worry about this.
    Last edited: Mar 21, 2017
  18. The stainless pads of that style, cheapest I ever seen - A one dozen pack of fat ones,   at Sams Club, for about ? $10, few years ago.   Marc
    Last edited: Mar 21, 2017
  19. tallbm

    tallbm Master of the Pit

    I'll keep an eye out for the pics!

    As for the PID I think you are correct with some of the reasoning behind MES temp swings.  I never went the MES way for burning wood internally.  I was AMNPS with mailbox mod from day one.  I plan to do sausage and in my research saw many posts about the MES inability to do smoke at sausage smoking temps.  Also I wanted to cold smoke so again I needed a different way to produce smoke and the AMNPS with mailbox mod was the answer.

    Finally the PID will allow me to push the temps just a little bit to help ensure I get acceptable skin texture when doing chicken and turkey smokes.  I couldn't ask for better solutions.  And now I can try your filter approach to hopefully reduce creosote and tar and such and see how the filter improves taste!  As you can tell I like to tinker and try to get high quality results :)
  20. Have you pulled it,apart yet to see how it worked?
    Last edited: Mar 29, 2017

Share This Page