Masterbuilt lp mailbox mod placement?

Discussion in 'Propane Smokers' started by brewsky, Jun 15, 2015.

  1. Hello!

    I have been smoking on a MES 30 for about 2 years, each year the control panel on the top would stop working and this year i finally said heck with it and bought the LP version.  Thanks to this forum i got smoking on my MES down to a t, now i need some help with this gasser.

     Ive read all about the problems and solutions for this smoker and have already installed a needle valve and ordered a gasket for the door.  Yesterday was my first smoke on it and getting the right amount of smoke was about impossible, guess im spoiled with my AMNS.  So I want to do the mailbox mod but im not sure where i should bring the flex pipe into my smoker at as this version doesnt have the vent on the bottom.  Im thinking between the burner and the water pan but im afraid that if i get to close to the burner that the flames from the burner will "eat" the smoke.  Im attaching some pictures to see what im talking about.

    O and also, what would be the easiest way to make the hole in the side of this smoker?  

     on the right side  between the stock chip tray and water pan is where im thinking of making the hole.

    Thank you!!
  2. mowin

    mowin Master of the Pit

    Did you ever do the mailbox mod? How does it work?
    I have the masterbuilt pro dual fuel two door smoker. Looks like yours, but has a round vent on each side.
  3. I have the same smoker as you and recently did a mailbox mod this past weekend. I plumbed the smoke from the AMNPS right into one of the lower round vents (for Brewsky - this location is pretty close to what you were thinking of, between the chip pan and water pan).

    My "mailbox" is actually a mini charcoal grill (Weber Smokey Joe knockoff) and I am able to use the preexisting air damper to adjust air to the AMNPS but so far that hasn't been necessary as I get about 3.5 hours of burn time from each row of pellets running the damper full open. The smoke produced by the AMNPS is great and I'm able to transfer almost all of it into the Masterbuilt smoker, but I am having a HUGE  problem with the airflow inside the smoker.

    When I pump smoke into the Masterbuilt smoker with the propane burner turned on, the wood smoke is getting sucked into the propane burner instead of circulating up, through the meat, and out of the top vent. If I had to guess, I'm getting maybe 10% of the smoke to make its way up through the meat and out, and the rest of it is getting sucked into the burner and wasted. If the propane burner is turned off, the smoke travels up and out of the smoker like it should. I love the idea behind the AMNPS tray, but extremely frustrated trying to figure out how to make everything work nicely with each other. 
  4. mowin

    mowin Master of the Pit

    Do you use anything to block the heat/flame? I think i read somewhere on here that you cant run without something over the burner like the stock chip pan.

    Wounder if a short elbow directing the smoke up would help???
    Last edited: Jul 15, 2015
  5. cmayna

    cmayna Master of the Pit OTBS Member SMF Premier Member

    Mowin, use a cast iron skillet.

    To all, I use either a AMNTS or AMNPS which is mounted in a cage/tray under the big hole underneath the burner.   The heat draws the smoke up and past the flame into the chamber. 
  6. cmayna - Do you have photos of this?  I'd like to see where and how it was done with it being under the burner as it might be the way I want to go.
    Last edited: Jul 15, 2015
  7. mowin

    mowin Master of the Pit

  8. I've ran it with the stock chip pan, stock chip pan covered in aluminum foil (foil melted pretty quick), and grilling vegetable basket over the burner. None of those helped, so out of desperation I've ordered a stainless steel baking sheet and I'm going to cut out a section of it to use as a more form fitting "cover" for the burner. 
  9. mowin

    mowin Master of the Pit

    How hot was the smoker getting? Do you have a needle valve in the gas line? My stock door therm is *60 off on the low side, so I got a maverick dual probe to monitor pit and meat temps. You running the stock therm only?

    Only reason im asking is maybe it running alot hotter than u think, and maybe the lower temps wont eat the smoke as much??

    I did see one pic on here where someone used a cast iron griddle with only a inch or two clearance on all sides as a heat baffle. Sounds like thats what your trying to do.
    Let us know how it works... good luck.
    Last edited: Jul 15, 2015
  10. I run the smoker with a needle valve around 250-275F as measured with a Maverick ET732 unit. I only use the stock door thermometer as a indicator to tell me if things are on/off.

    I wanted to find a piece of cast iron to block off the burner, but all the griddles I've found are either too large or too small. When I was testing around with aluminum foil, I found that even a 1" gap is still too large and the smoke will still get sucked into the burner. Hopefully this stainless steel baking sheet won't be too difficult to cut and fit into the firebox since it's the last idea I have
  11. mowin

    mowin Master of the Pit

    Draft issue maybe? Seems most that are running amnps or amnts have also added a smoke stack.
    Does it work better if you leave the door cracked?
    Last edited: Jul 16, 2015
  12. It definitely works better if the door is cracked open. Out of frustration, my friend and I cut a 3.5" hole in the top/center of the smoker. It didn't perform any better, but we also didn't have anything to use as a smoke stack.
  13. mowin

    mowin Master of the Pit

    Not sure a stack would help. Im holding off on my mailbox mod in hopes you find a soultion.

    Kinda courious how placing a amnts inside would work as its closer to the burner then the side vent. Yet guys are saying this works great....
  14. Yeah, I'm not sure how a stack would improve it either seeing as I already have a gaping hole of frustration at the top of my smoker. I have a extra 5" to 4" ac vent reducer when I bought parts to plumb the "mailbox" into the smoker. It's at least 8" tall. I might just throw that on top of the smoker to see if anything changes at all.

    I just got the stainless steel baking sheet in today from Amazon. That will get cut and fitted this weekend and I'll keep updating to see where I end up with this whole project.
  15. smokeymose

    smokeymose Master of the Pit

    I have the same unit, Brewsky, not because the mes broke, but because the house wiring couldn't handle it. The gasser is completely different, but I've learned to love it.
    You've noticed, I'm sure, that they run hot, and the door 'stat isn't reliable. I regulate the temps by cracking the door(s) open. It doesn't take much unless it's really hot outside. I believe that's why the door latches are adjustable! I even got a small dining tarp to keep in in the shade. I haven't had any trouble making good smoke with both chips or chunks with a cast pan, although I fill and level the "wood tray" with lava rock to keep the flame from getting to the pan.
    BTW, I got rid of the stock water pan and just use a disposable one sitting where the old one is, or on the bottom rack (gotta love all those adjustable racks!).
    All that being said, I'm looking into the mailbox thing because I'd like to cold smoke using my MB. I did a little experiment yesterday placing an amazn 6" tube in the bottom. At outside temp of 41, just that alone took the chamber to 113 before leveling out at around 80! I'm thinking on going in on the right side as low as possible. The burner won't be on while I'm cold smoking.
    I'd be interested to see what you come up with!

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