Help on Air intake - My attempt at "Mailbox mod"

[Runas06]

Hi SMF Master's,

I'm new to this forum, but have deep diving through all of your valuable contributions since Thanksgiving. Apologies in advance for this being a long-winded post. I'm still a total newbie, but tried my best to read through as much of the wisdom you all have compiled.

Just getting into smoking after my buddy let me borrow his MES30, completely stock, over Thanksgiving - I had the most delicious turkey of my life. I'm hooked now.

Bought myself a MES 30 (20071117 - apparently a hybrid of gen 1 and gen 2.5?), Leg kit, and cover on a great sale directly from masterbuilt (total under 200 for all of it)

I'm in the process of making my own spin on the mailbox mod. I used a 16" domed roasting pan made out of carbon steel. It has a rack at the bottom, which I thought was perfect to elevate the AMNPS for airflow. Cut off the handle so I can fix the adjustable adapter into it at the apex(pending hole saw getting delivered). Also gutted the interior housing.

I'm hoping to get some input on three things:

1. Does this design have any dumb "gotchas"?
2. I like the idea that I *think* Bear offered - fill the water pan with sand to increase thermal mass to help with temp fluctuations. Is this worthwhile or pointless?
3. Would you please offer me some suggestions on drilling air intake locations in my smoke "oval"? Since this is not a mailbox, I wasn't quite sure. The closest thing I could compare against was the popcorn tin mod, but I didn't see a description on air intake locations.

Thanks SMF!

 

[SmokinEdge]

Air flow into the smoke pot? Is it adjustable??

 

[CFLJOHN512]

You will need an intake on the roasting pan so the pellet tray can get air. I didn’t see any mention of that. Other than that looks good. You’ll love the MES. I’ve got a similar model.

 

[Runas06]

Air flow into the smoke pot? Is it adjustable??

Hi SmokinEdge,

Thanks for your response. I'm asking where should I still air intake holes in the roasting pan, which I'm using for a external smoke box. I saw suggestions when using a mailbox... Those seemed to suggest 3 holes in the door. Two near the bottom of the door, one at the top of the door

 

[Runas06]

You will need an intake on the roasting pan so the pellet tray can get air. I didn’t see any mention of that. Other than that looks good. You’ll love the MES. I’ve got a similar model.

Hi CFLJohn512,

Thanks! I hope so, smoking stuff is going to quickly turn into an obsession haha. Do you have any idea where I should still intake holes? Bottom? Two on each side? Ect

 

[Winterrider]

I would drill 2- 1" holes on 2 different sides of pan. Could always tape 1 up if very windy conditions.

 

[TNJAKE]

My only recommendation is move it out of your living room

 

[dr k]

You could put four 1/4" holes in the bottom pan an inch or two up from the bottom symmetrically so there's a hole every 1/4 way around the bottom pan. Put two bricks on edge to hold the bottom pan in place and put the grate on them to have the Amnps the height where the lid meets the bottom or higher inside the lid so all air has to pass the Amnps from underneath and around it to get to the vent pipe. You can always make bigger holes but there should be enough air and small enough to keep wind from blowing in. Or four half bricks in between the holes to not block air to elevate the grate.

 

[Runas06]

My only recommendation is move it out of your living room

Man... You and my wife, both against the living room idea... Seems like a solid idea to me haha

 

[Runas06]

You could put four 1/4" holes in the bottom pan an inch or two up from the bottom symmetrically so there's a hole every 1/4 way around the bottom pan. Put two bricks on edge to hold the bottom pan in place and put the grate on them to have the Amnps the height where the lid meets the bottom or higher inside the lid so all air has to pass the Amnps from underneath and around it to get to the vent pipe. You can always make bigger holes but there should be enough air and small enough to keep wind from blowing in. Or four half bricks in between the holes to not block air to elevate the grate.

Dr K,

Thank you! That makes a lot of sense to me. I'll give that a shot

 

[Runas06]

I would drill 2- 1" holes on 2 different sides of pan. Could always tape 1 up if very windy conditions.

Thanks for the suggestion. I think I'm going to start with 4 1/4 inch holes, two on each side, similar to your suggestion. Then bore out the holes to a larger diameter if the AMNPS is chocking out.

Very much appreciate everyone's input! Going to do the typical first smoke... Boston butt. Will let you all know how it turn out!

 

[forktender]

If you have a Harbor freight near you or any hardware store for that matter go buy yourself a Uni bit/ step drill bit. They come in handy big time. Your mod looks ligit.
Just drill a few holes on the side of pan below the rack.
Id start with two 3/4-1" holes dead center of the pan.
Here's a link to the bits.

Titanium-Coated High-Speed Steel Step Bit Set, 2-Piece

Amazing deals on this Titanium-Coated Hss Step Bit, 2Pc at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Welcome to the club.
Dan

 

[SmokinEdge]

Hi SmokinEdge,

Thanks for your response. I'm asking where should I still air intake holes in the roasting pan, which I'm using for a external smoke box. I saw suggestions when using a mailbox... Those seemed to suggest 3 holes in the door. Two near the bottom of the door, one at the top of the door

Air inlets really need to be at the smoke tray level at minimum. A little lower if possible would be best. The out let cannot exhaust any more that the inlets let in, so you will need to size the inlet to match your exhaust. Remember you don’t have a fire burning craving oxygen. It’s smoldering. So low holes to provide air and some air holes higher to help move the air through the exhaust. This all is dependent on your smoke stack at the cooker. You need to create draw or draft. First in the smoke pot but then ultimately out of the smoke chamber.

 

[Runas06]

If you have a Harbor freight near you or any hardware store for that matter go buy yourself a Uni bit/ step drill bit. They come in handy big time. Your mod looks ligit.
Just drill a few holes on the side of pan below the rack.
Id start with two 3/4-1" holes dead center of the pan.
Here's a link to the bits.

Titanium-Coated High-Speed Steel Step Bit Set, 2-Piece

Amazing deals on this Titanium-Coated Hss Step Bit, 2Pc at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Welcome to the club.
Dan

Dan,

Thanks for the suggestion! Great idea, I actually already have some step bits I've been itching to use... Can't believe I didn't think of that. Appreciate the suggestion and the welcome!

 

[Runas06]

Air inlets really need to be at the smoke tray level at minimum. A little lower if possible would be best. The out let cannot exhaust any more that the inlets let in, so you will need to size the inlet to match your exhaust. Remember you don’t have a fire burning craving oxygen. It’s smoldering. So low holes to provide air and some air holes higher to help move the air through the exhaust. This all is dependent on your smoke stack at the cooker. You need to create draw or draft. First in the smoke pot but then ultimately out of the smoke chamber.

SmokinEdge,

Thanks for your advice - that's exactly the question I was trying to answer. I saw posts using an actual mailbox talking about two holes low in the door, then one higher in the door to help the draft. In this oval pot, it seemed more complicated.

Maybe four smaller holes low (below raised AMNPS), one 1/2 inch hole above the AMNPS to facilitate airflow? Then bore out the holes larger if necessary

Does that make sense or am I over thinking this?

 

[SmokinEdge]

Also remember, in circular holes, if you double the hole size you triple the volume. So one hole at 1/2 inch is equal to three 1/4 inch holes in volume. Or we can expand the thought to flow full volume of a 4” pipe, you would need three 2” pipes.

 

[Runas06]

SmokinEdge,

Thanks for your advice - that's exactly the question I was trying to answer. I saw posts using an actual mailbox talking about two holes low in the door, then one higher in the door to help the draft. In this oval pot, it seemed more complicated.

Maybe four smaller holes low (below raised AMNPS), one 1/2 inch hole above the AMNPS to facilitate airflow? Then bore out the holes larger if necessary

Does that make sense or am I over thinking this?

Th

Also remember, in circular holes, if you double the hole size you triple the volume. So one hole at 1/2 inch is equal to three 1/4 inch holes in volume. Or we can expand the thought to flow full volume of a 4” pipe, you would need three 2” pipes.

Whoa, you just blew my mind.

I'm by no means an engineer, so that is incredibly useful info. Thank you!

I noticed you mentioned a stack - does that help quite a bit? I'm in "build mode" so would rather do fabrication now. If it helps substantially, and suggestion on stack height?

 

[SmokinEdge]

Lol, I’m just trying to illustrate the dynamics. You are building so keep everything in mind.
I would follow the advice already given. You can always add more. You are going to go to trial with what you start with, then tweak it to get where you want to be . At this stage of discovery, less is more. You can always increase or add more.

 

[forktender]

Dan,

Thanks for the suggestion! Great idea, I actually already have some step bits I've been itching to use... Can't believe I didn't think of that. Appreciate the suggestion and the welcome!

They work better than hole saws drill a pilot hole big enough to fit the tip of the step bit in and go for it.
Wear safety glasses they throw some shavings.

 

[forktender]

Also remember, in circular holes, if you double the hole size you triple the volume. So one hole at 1/2 inch is equal to three 1/4 inch holes in volume. Or we can expand the thought to flow full volume of a 4” pipe, you would need three 2” pipes.

True but way overkill for this situation two 3/4-1'' holes should be more than enough. My UDS only has three 3/4'' air inlets and that is supplying oxygen to a much bigger fuel load.