Mailbox Mod Caught on Fire

[danisrael8]

Hi all,

Long time lurker first time posting. I had a little incident today while I was smoking a pork butt in my mes30 with the mailbox mod. I've smoked a handful of things with the mailbox mod and never had an issue however the pictures speak for themselves. I believe the pellets caught on fire and jumped rows causing the mailbox to burn up. Like normal I lit the pellets outside the mailbox and waited 10 minutes until the flame was burning strong. I blew out the flame and carried it to the mailbox. I was getting a good stream of TBS and left the smoker to go change the oil in my car and clean out the garage. You can see on one of the pictures where there seems to be some melted residue on the amps. I was only gone for about 2 when I realized the smoke stopped .

The reason I posted this here is to ask do you think the smoker is safe to use? I threw away the pork butt in fear of toxic fumes form the galvanic mailbox but could it have contaminated the smoker as well? I'm a little disappointed our super bowl party will be missing the pork butt but I'm glad my house didn't burn down!

Thanks for the help,
Dan

 

[SonnyE]

You probably did the right thing tossing the meat.
"When in doubt, throw it out." Especially if feeding other folks.
I believe I would clean the smoker very well, then decide.
Personally, I'd be apt to continue using it. But I'm not there to decide, you are.

When I first read your title, I was going to say, "No, No, No, you can't use a plastic mailbox!"

 

[dr k]

Some people burn out the inside of galvanized mailboxes to get rid of the zinc. I'd keep using it. Most do the same to 55 gallon drums as well when making a UDS.

 

[SonnyE]

Masterbuilt has what I'd consider a great/good alturnitive:
http://www.homedepot.com/p/Masterbuilt-Electric-Slow-Smoker-20070112/203868163

Just attach you a dryer vent (Metal) hose, or hard plumb it to your box.
Cool smoke.

 

[GaryHibbert]

That was really unfortunate. Never had a problem like that, and as you can see, my "mailbox" is just homemade out of 3/4 inch plywood--been using it for years.

I wouldn't be overly concerned about the MES itself. Just give it a good cleaning (the mailbox too) and you should be good to go.
Gary

 

[danisrael8]

Thanks all for the replies! I'm glad to hear I can still keep using the MES I'll give it a good cleaning and keep on chugging on. I think I may have nuked my pellets a little too long in the microwave cause when I pulled the AMPS out there were embers in each row indicating the whole tray caught fire. Next I need to control the airflow to the mailbox as that may have lead to the fire too.

Gary I like the design you have I wonder if I can fireproof it with some stainless sheets. Something I'll look into.

 

[tallbm]

Thanks all for the replies! I'm glad to hear I can still keep using the MES I'll give it a good cleaning and keep on chugging on. I think I may have nuked my pellets a little too long in the microwave cause when I pulled the AMPS out there were embers in each row indicating the whole tray caught fire. Next I need to control the airflow to the mailbox as that may have lead to the fire too.

Gary I like the design you have I wonder if I can fireproof it with some stainless sheets. Something I'll look into.

I once did like 5 rounds of nuke pellets for 1 minute, stir and let cool for 2-3 minutes.
They lit up very very easily. At one point I opened my smoker for some reason and I noticed the pellets got fire from the extra oxygen flow due to the suction of me opening the smoker door hahaha.
I caught it immediately and blew it out and made a note to self not to mess with opening the door until everything was finished. I also kept a close eye on the temp of the smoker to catch any high swing in temp that would be explained by a pellet fire hahaha.

I've since only done 2 rounds of nuking my pellets to avoid the issue :)

 

[johnmeyer]

I wanted to make a mailbox mod but was put off by the coatings I found on all the mailboxes. In looking for alternatives, I found some popcorn tins lying around. The interior is food grade tin plate. I describe my experience here:

Mailbox (Popcorn) Mod (with a small twist)

I've never once worried about food safety due to zinc, plastic, or paint on the interior, like I would with most mailboxes. Also, it was free, but even if I wanted to buy one, I found places that where you can get them for well under $15, shipped.

 

[Bearcarver]

Filling your AMNPS too full can make it jump across rows.
I top mine at between 1/4" and 3/8" from the top.
The fuller you make it, the closer the rows of pellets get to each other.

Bear

 

[jimmyinsd]

just curious, in these mailbox mods, why do people always cut the exhaust in the end of the mail box and not go right off the top of the mailbox? does the hole location or the length of flex duct serve any functional purpose

 

[indaswamp]

Two things:
draft... you want the length of the mailbox to help you with drafting the smoke into the piping.

creosote: it will collect in the mailbox with the smoke having to turn 90* to enter the smokehouse.

This is my assessment.

 

[dr k]

The back is flat and easy to work with for me. I want to use as much of the mailbox to condense heavier volitiles and using the full length draws smoke across the top and bottom of an elevated Amnps, keeping it going. I didn't drill holes in the door. The two bottom pencil diameter sized mounting holes I left open and plugged all others. Plenty of air comes through those holes and at the hinge of the door. The face of the Amnps that was lit through the blow torch hole is right above the two holes. It's a straight line from the bottom of the door to the 3" opening at the top rear with the Amnps in between. I turn around the Amnps after five hours when using more than one row so it always burns with the draft. I love this mod.

 

[jimmyinsd]

Two things:
draft... you want the length of the mailbox to help you with drafting the smoke into the piping.

creosote: it will collect in the mailbox with the smoke having to turn 90* to enter the smokehouse.

This is my assessment.

not trying to be argumentative, but what could draft better than allowing the heat to rise straight up from the chip tray into an elbow and then turn into the smoker where it rises up the through the meat? I would think that the shorter the horizontal run the better it would draft. I am not sure about the creosote theory

 

[johnmeyer]

not trying to be argumentative, but what could draft better than allowing the heat to rise straight up from the chip tray into an elbow and then turn into the smoker where it rises up the through the meat? I would think that the shorter the horizontal run the better it would draft. I am not sure about the creosote theory

One of the main features of the mailbox mod is that it condenses the creosote (which is bitter and numbing) so it doesn't end up on your food. The difference after you start smoking with the mailbox mod is not subtle: the food tastes remarkably better.

To remove this creosote via condensation on the metal surfaces of the mailbox, you want the smoke to travel over as much metal surface as possible before existing the mailbox. This argues for putting the exhaust on the back. Moving the smoke over the longest possible metal surface is so important that one person added twenty feet of metal conduit between the mailbox and the smoker in order to increase the amount of creosote removal.

And, as already pointed out above, if you have worked with sheet metal before, attaching conduit to the curved upper mailbox surface would be a lot more challenging than simply cutting a round hole in the flat back side of the box.

As for the draft created by the mailbox itself, the convection draft (hot stuff rising) that pulls the smoke out of the mailbox actually has almost nothing to do with the mailbox construction and instead is created by the much hotter and bigger smoker enclosure. We know this for sure because dozens of people have posted about how it is sometimes difficult to get the smoke to draw into the smoker when doing a cold smoke, i.e., no heat whatsoever inside the smoking enclosure. The convection inside the mailbox mod doesn't help because it is way too small a volume of air to be able to force the huge volume in the smoker to move. As a result, some people have added cold-smoke fan assists to their mod, usually at the exhaust port on the smoker and not as a blower into the mailbox.

So, there is really no reason whatsoever to put the hole on the top, whereas there are several good reasons to put it at the back.

 

[daveomak]

I see why it caught fire... You did not have any holes in the door to allow for air to enter the mailbox... The confined space allowed for a "flashover"... ALSO, holes in the door allow for "once through" air flow to remove volatiles and cool the smoke stream so creosote will condense...
I highly recommend using this set up.. The upper air hole in the door stops recirculating smoke... makes for clean tasting smoke and stopping recirulating insures plenty of oxygen for the pellets to burn... recirulating smoke is low in oxygen.. and put legs on the AMNPS for better burning...
.. ...

 

[chopsaw]

I have mine tapped in the side at the back of the mailbox . Horizontal run , rise , and a return . Added a stack on top , and drilled the holes in the door after talking with Dave .

Collects nasty condensate at the start of the rise , and in the mailbox itself .