Fuel tank to 55-gal. barrel build

[llw88]

View media item 553639View media item 553638Sick of the drastically changing temps on my cheap store-bought offset so doing my first build using an old rectangular fuel tank as a firebox and for now a sealable 55-gal drum as a cooking chamber. Hope to later replace that with a 250-300 gal cylindrical fuel tank.

Here are some pics of the firebox I have. As of now I have cut the door, cleaned it and burned it out. I plan to line it with fire bricks on the sides, capped on top with a sheet of steel and more fire bricks or an insulation blanket on top of that to insulate the tank.

I'm looking for ideas about the best way to cut the exhaust on the back side of the firebox. Ideally, I was thinking about some sort of square-to-round aluminum duct fitting for cost-effectiveness and ease of cutting (I only have a grinder to cut with so circles would be tough for me). But I'm struggling to find the right ductwork at a reasonable cost. Any other ideas on the connection point? I think I need something in between because the drum has a little lip to it so it won't fit flush against the firebox to just directly match holes and connect them with bolts.

Thanks in advance.

 

[llw88]

I had to buy a house to continue my smoker build after my landlord started asking justifiable questions about me cutting up and burning out a diesel tank in the backyard. But now I'm back in action.

Looking at using and HVAC wall vent or wall flange as an exhaust from my firebox to the 55 gal drum I'll use as a cooking chamber.

My question to the forum is do you think I'd be safe with an aluminum piece for that? It would be cut into the back of my firebox, with just the lip or flange on the inside and then an elbow connecting to the drum outside the firebox. So no direct contact with flames, but won't be far away. Do you think aluminum would hold up well enough? Thanks in advance.

 

[llw88]

Finally put together my fuel tank to 55 gallon rig. Lined the tank with fire bricks with two plates of 1/4" steel on top, connected the two pieces with a stainless HVAC vent. It ain't pretty but it works pretty well.

Haven't sealed up the connection yet. Anyone have any ideas on sone sort of high temp gasket or something to make the connections to the stainless vent airtight? Thanks in advance as always.