Tim's gravity feed (mini)

[Tim Schmidt]

Ordered my plans a few weeks ago, I am excited to get Started. It has been a long time coming.
Just want everyone to know I really enjoy following the builds on this forum, I have learned a lot..
I will post pictures as my build progresses.

[Tim Schmidt]

Purchased this insulation at Menards. Plan on using it to fill square tubing, and to line the panels and doors. It is rated to 2080 degrees f. I applied a nap gas torch to the insulation. Only dis colored it a bit from 6 " away. Not sure if anyone else has used this material.
Quick question to everyone, are you wrapping the firebox, or just lining the walls in the chute/ Firefox chamber?

[SmokinDTown]

Tim, I wrapped the FBA on my BUGF smoker. Puff insulated the walls by using expanded metal on the inside. I like his method better. I will use it on my build.

[CaliforniaSmoke]

I ordered the Roxul RHT 80 for mine, but I still have the same question. I'm planning on filling the tubes, and probably insulating the firebox as well if I have enough materials.

[Puff]

That was Frank's idea. He mentioned it once while on the phone and it makes sense. It acts as a "breathable" interior wall and supports the rigid insulation a bit more. It's not even a complete wall but strips that run left to right in large spans and whatever pieces I'd had that fit a full wall or top, I used them that way.

[WyomingLawDog]

Ok you guys got me lost on the insulating of the fire box area. I know about insulating the walls between the interior and exterior metal and putting insulation in the square tubing. I figured the wall between the firebox area and the cook chamber is insulated just like you do on the exterior walls. But I am lost as far as lining the firebox and using expanded metal. So if anyone is to that point if you can post pictures of that, I would appreciate it. Thanks

[CaliforniaSmoke]

Ok you guys got me lost on the insulating of the fire box area. I know about insulating the walls between the interior and exterior metal and putting insulation in the square tubing. I figured the wall between the firebox area and the cook chamber is insulated just like you do on the exterior walls. But I am lost as far as lining the firebox and using expanded metal. So if anyone is to that point if you can post pictures of that, I would appreciate it. Thanks

I don't think you want to line the inside of the firebox, that seems like a Bad Idea.

The expended metal bit is (I think) using scraps of expanded metal to hold the insulation against the inner wall of the cook chamber next to the charcoal chute. Unlike the other three walls, you only have one layer of sheetmetal there. I think you could use the same approach to wrap the *outside* of the firebox in insulation to help retain heat in the firebox. I think I'm going to try that, I don't see how it can hurt.

[WyomingLawDog]

Ya, I was not think insulating inside the firebox it self, just on the outside of the firebox in what looks like a little area around the charcoal chute and firebox that I believe are connected with the removable fire grate. What is messing me up is that inner wall between the CC and FB, can I just treat it like an exterior wall and put sheet metal on both sides where it is insulated between and inside the tubing just like an exterior wall or will the charcoal chute/fire box be in the way?. I know the transfer tube comes through that inner wall into the CC to deliver the heat and smoke but I don't see why I can't treat it like an exterior wall and put metal on both sides and insulate like the exterior walls unless the firebox/chute are mounted partially between the tubing of that inner wall. By picture that chute looks to be welded up against the tubing of that inner wall, what if I put a skin on that side and mounted the chute/firebox to that skin and the transfer tube goes through the insulated wall? I hope I am making sense, like I said that inner wall is what is throwing me off about it being insulated and all.

[Puff]

I hope this illustration will clarify what I did on my first big gravity feed. If I had done this on the computer it would certainly be prettier but would take me four or five hours this only took four or five minutes .

The yellow lines represent the insulated area and it is a view as if there was no top and you were looking straight down .....kind of like Google earth. The airspace in the firebox and charcoal chute section is created using expanded metal on the interior walls to support the insulation and while it did not need the double layer of insulation against the cook chamber from the firebox I had the material sitting here anyway so I used it. Those expanded metal strips are only scraps to help support the insulation in that area. Don't forget the bottom and of the smoker are also insulated. But for the satellite view... They have been removed!

[Tim Schmidt]

Making some good progress. Going to try and get the cook chamber completed this weekend.
I probably know the answer, but does it really matter if the cook chamber is painted. I'm assuming the smoke and grease will act as a natural preservative for the metal.
Also, I'm getting a pretty good feel for my Lincoln mig welder. For those of you that have welded 16 ga sheet metal, what size wire do you prefer?

[Puff]

Hey Tim.... Looking really good, I don't think you will want to paint the chamber inside. The burning paint will give off undesirable fumes which will invade your food. no reason to deal with that. A good cleaning of the steel before you FIRST use it and proper seasoning will prepare of the inside of your cook chamber for many many uses. And like they say about fine wines and some humans ... it gets better with age

If it gets better with age, then I'm still waitin

Ive used both .030 and .023. I don't see too much difference but you can deposit a lot more material with that .030 if you linger too long. I think the .023 leaves a fine bead .

[Pete Mazz]

It's not Google Earth.... It's Google Puff!!

[Tim Schmidt]

Thanks Puff, that is what I thought.
Things are going together nicely.
Love the plans. I did have to take take off about 1/2 inch from the smoke transfer tub, after a completed the firebox/ charcoal chute assembly.
Also Puff, do use any type of fan on you big GF.
Thanks again?

[Puff]

Funny you had to trim the transfer tube... I did also on the big one about 3/8". I built a my own pid controller and fan with probes and a nice pretty case. I never did install it. The bigger gf performs so well...I really mean THAT WELL, that I don't need it. Once the temperatures are up to the point they need to be I simply set the ball valve so it is a little more than halfway closed and it will stay at 230° four hours . A slight bump of the ball valve handle will change two or 3° I don't know how that controller could be any more accurate than that so it sits in a box on the shelf

[WyomingLawDog]

Tim, looking good, keep up the pictures, helping put things together in my head. I hoping to weld the frame together on Sunday. I have a KCBS BBQ competition to judge tomorrow. Puff thanks for the drawing, so the expanded metal is helping to keep the insulation attached to the inner wall? I think I am getting that part figured out, I knew there was air space inside the part of the smoker where the firebox/charcoal chute are located. The expanded metal strip is just keeping the insulation up against that inner wall? Thanks Puff

[Puff]

Yup. And some of those scraps are ugly... But who sees it? Some guy who reads one of my hidden messages in 2123AD?

[NM_Wanderer]

Looking great Tim!! Keep the pictures coming. Can't wait to start mine but I have to pay off my new horizontal band saw first.

[Tim Schmidt]

Finished welding the cook chamber sheet metal today. Once I figured out how to weld the sheet metal, it turned out ok. Initially I had an issue with burn through.
Not sure if this technique has an official name, but it produced some descent welds.
I did the inside corners in two passes.
The first pass I pushed my mig gun, I did a straight weld directly into the inside corner. The second pass, I also pushed the gun, but this time I used a small circular motion from side to side. I'm assuming the first straight bead thickened the metal, which prevented the second pass from burning through. I also noticed, I did not have near as much popping compared to when I tried welding the inside corners in a single pass.
I used .030 wire.

[CaliforniaSmoke]

Hey Tim, that's starting to look like a smoker! Lots of seams to weld up, a lot especially if you're doing two passes. You should be able to weld that in one pass, but I'm guessing I'll have trouble welding these long seams too.

[Puff]

During this stage of assembly, I took out a bright light at night and looked at all of the seams in the cook chamber. Makes it very easy to see any possible leaky gaps.

[Tim Schmidt]

I first tried welding the inside corners in one pass, but the welds did not look great. I also had a lot of popping. I am assuming it has something to do with the sheet metal. I have had no problems welding anything else on this project.

[Tim Schmidt]

Great idea. I will give it a try this week.
Tim

[Rodcrafter]

Looking good!


Making memories.

[Tim Schmidt]

Have not made much progress this past week. Getting kids ready for school.
Just wondering how everyone is lighting the gravity feed smokers?
Suspect a torch would be the easiest way. I was trying to think of some kind of built in igniter.
Thanks in advance.
Tim

[CaliforniaSmoke]

Have not made much progress this past week. Getting kids ready for school.
Just wondering how everyone is lighting the gravity feed smokers?
Suspect a torch would be the easiest way. I was trying to think of some kind of built in igniter.
Thanks in advance.
Tim

My thinking was to get maybe half a charcoal chimney of coals going and dump it in the chute, then fill with charcoal and wood chunks. I expect a big torch or weed burner would work great too.