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I am about to do a mailbox mod to my Masterbuilt and have a question.


Joined Dec 17, 2013
I have the propane version, 2 door and am about 3/4 done with doing the mod.

I took the brace off of the smoker and am ready to cut out the back of the mail box.

Unlike all the other pictures of my smoker that I can find on the internet, mine has 2 vent holes already cut into the sides.

I was planning on leaving them alone and cutting out the back of the mailbox and directly attach it to the smoker.

The usual mod was to cut a round hole in both the mailbox and smoker and running a small piece of pipe between the 2.

For the smoker, I was hoping that I could leave the smoker's hole alone or maybe snip out the center pieces if needed.

For the mailbox, recall that I am going to directly attach it to the smoker so no piping needed.

So, would the shape of the hole be important ? Would it still work ok if I made a square hole that is slightly larger than the hole in the smoker ?

The end result would be a mailbox with a square hole bolted to the smoker with a partially impeded round hole.

I also have a battery powered 5" fan that I am going to mount at the other end of the mailbox to help force the smoke.

What do you think ?


Master of the Pit
OTBS Member
Joined Jun 24, 2011
I think it should work just fine.  you may want to put a high temp sealer around the square cut out before mounting if you are worried about any smoke leaking.


Epic Pitmaster
OTBS Member
Joined Oct 4, 2012
Square should work. You shouldn't need a fan to move the smoke, especially during hot smokes. It will naturally draw with the heat. I have plans to mount mine directly to the back of my GOSM propane smoker eventually. I will go round, but that's only because I have a 3" hole saw. I will plan to rivet or bolt it to the back and then use high temp where the mail box meets the smoker.

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