Mailbox Mod not working on 30" Smoke Hollow

[Will Sergent]

Good morning,
I've been a follower of the forums, but this is the first time I've posted. I've gotten some excellent ideas from you all, so first off thank you.

I bought a 30" Smoke Hollow smoker on sale recently. (50% off actually). It's been a great smoker, but I got tired of loading chips all the time so I bought one of the AMNPS Trays to help make my life easier. I also wanted to be able to do cold smoking so I added a mailbox mod. For my mailbox I ended up using a cheap toolbox and 3" dryer vent into the side of the smoker. I also added a new stack to the top of the smoker as I didn't like the vent on the backside.

If the propane burner is off, it tends to do pretty well. However, if I turn the heat on I can't get any flow through the smoker unless I leave the door open. That obviously makes me think it's an airflow problem but I'm not sure how to address it.

At the imgur link below are some photos so you can see what I'm dealing with - I'm open to any and all suggestions.

 

[gmc2003]

Welcome to the site, I can't see your link, but that may be because this is your first post and I think you need admin. approval until you hit ten posts. Anyway glad you joined and someone will chime in with an answer to your question.

Chris

 

[Will Sergent]

Thanks! Maybe this will work.

 

[chopsaw]

I can see it now ,,, Like Chris one of the guys will help you . I don't know enough about how a propane smoker works .

 

[gmc2003]

That link worked, the pics are also showing up in your original post. There are allot of mailbox mod experts on site that will help you out. I don't need one on my WSM so I'd only be guessing. My first thought is maybe you need a hole cut above the pellet tray. I've seen many ventilated that way, but wait and see what the others recommend.

Chris

 

[hillbillyrkstr]

You want your dryer vent hose as high as it can get on the side of the mailbox mod and your vent holes as low as possible right in front of the side you place your tray.

I’ve also heard propane smokers don’t do well with the tray because the flame eats up all the oxygen. Not sure if this would be an issue with a smoker that has a mailbox mod.

Scott

 

[Bearcarver]

I'm not well versed at using an Amazing in a Gasser, or with a Mailbox & Gasser.
My AMNPS works perfectly in my MES Wattburner.
If the other suggestions don't help, contact daveomak ---He seems to be the Mailbox Guru.

Bear

 

[Will Sergent]

You want your dryer vent hose as high as it can get on the side of the mailbox mod and your vent holes as low as possible right in front of the side you place your tray.

I’ve also heard propane smokers don’t do well with the tray because the flame eats up all the oxygen. Not sure if this would be an issue with a smoker that has a mailbox mod.

Scott

Thanks for responding. The dryer vent hose is as high as I could get it on the toolbo. The vent holes are on the opposite side of the toolbox towards the bottom. I keep the tray right near it.

Thankfully, I have no problems with the tray staying lit. The smoke ends up just pushing out the vent holes (and the few cracks in the box) but will not push up the vent tube into the smoker.

 

[SonnyE]

You've encountered one of the problems with a gasser.
I think where you have your mod entering the chamber is high, so that could be a part of your woes.
But gassers tend to burn up the smoke. Any flame will consume smoke.
But for cold smoking you should be fine.
Do you think you could reduce the flame of the burner to a pilot sized flame? Some guys (me too) use a flow reducing valve to control the amount of gas going to the burner. (I do that with my boiling rig.)
Daveomak uses nails to reduce the flame holes in his burner.

Incidentally, that imagur link opens your whole picture account. A few Ahem, interesting pictures there Will.

 

[Will Sergent]

You've encountered one of the problems with a gasser.
I think where you have your mod entering the chamber is high, so that could be a part of your woes.
But gassers tend to burn up the smoke. Any flame will consume smoke.
But for cold smoking you should be fine.
Do you think you could reduce the flame of the burner to a pilot sized flame? Some guys (me too) use a flow reducing valve to control the amount of gas going to the burner. (I do that with my boiling rig.)
Daveomak uses nails to reduce the flame holes in his burner.

Incidentally, that imagur link opens your whole picture account. A few Ahem, interesting pictures there Will.

Yeah, if I put my mod any lower it's right on top of the burners. I have a needle valve installed - but obviously I start to lose temp if I do it too much. I'm not sure what to do.

And I'm not sure what you are seeing - since I don't have an IMGUR account and just uploaded that without an account. So... no idea what's going on there.

 

[daveomak]

I think what may be causing your problems is.....
The smoker body acts as a chimney... The opening around the burner is disrupting the "chimney" effect... Seal off the hole around the burner with aluminum foil and see if that solves the problem...
Also, have the flex pipe on a steady rise from the MB to the smoker... No dips etc... Also, the MB needs an air supply... Since there is no view of the MB, I can't tell what sort of air inlet you have..
The exhaust must be wide open...
Also, if your smoker body is below ambient temp, it's creating an air dam of cold air... fire up the burner for 4-5 minutes to warm the smoker... that should start the draw...
Also try shortening the flex hose... mine is about 3' and runs uphill continuously.....

 

[Winterrider]

Can you move your flex pipe down to the vent on the bottom so it would be as low as burner and seal other hole to see if that helps?

 

[gmc2003]

Thanks! Maybe this will work.

And I'm not sure what you are seeing - since I don't have an IMGUR account and just uploaded that without an account. So... no idea what's going on there.

Clicking on the link "this will work" brings us to an IMGUR account. Strange.

Chris

 

[SonnyE]

And I'm not sure what you are seeing - since I don't have an IMGUR account and just uploaded that without an account. So... no idea what's going on there.

If I click on your picture, it takes me to what I thought was your imgur account.
I see now! I clicked on "Next Post", instead of scrolling down. I thought it was taking me to your next picture.

If you were to close, or restrict the lower vent(s), it may increase the draw on your mailbox mod.
Everybody has to do a bit of experimenting to find their way when modifying.

Saving you the drama, and cutting to the chase, here's my MES 30.
Highly modified, it goes from temperature controlled cold smoking, up to the high limits (which is closer to 310°).
I actually use a full 8' of heavy dryer vent pipe to additionally cool the smoke from my box. With my Inkbird controller, I can control my cold smoking temperature to a 6° swing at set point. 4° below, 2° above, a 65° set point, inside my smoker box. (Or it might be 2° below, then a coast up to 4° over SP, but it runs damn tight). So I'm happy.

A lot of this is tinkering to get what you like. Like Dave said, pre-heating your box to establish the necessary drafting would likely help. It does for mine. It is also why I put a stove pipe on mine, to help it draft.
If you find you are scratching your head, maybe increase your stove pipe length to give it more draft. Might do the trick.

 

[biteme7951]

What Dave said, and try closing down the lower vents (keep top wide open). this may pull the smoke thru the tube from the MB

Barry.