insulated firebox

[FatDaddy]

Wanting to know what how i could go about insulating my firebox? my step dad and i could fabricate it if i had an idea of how they insulate them? is it just a box within the box with a gap inbetween them? thanks for the info.

also on a pit like mine is there a need for a baffle? ive thought about adding tuner plates to it, as well as another set of racks on the inside making it a double rack.

 

[Sawdustguy]

I think the easiest way would be to build a steel box around your present firebox. The surrounding steel box can be supported from your present firebox by welding 1" x 2" steel bar on each corner on all sides. Weld the outter metal sides to the steel bar and then weld the sides together. Build the box with the top section last. Before you weld the top section fill the 2" gap between the firebox and the outer box with mica pellets.

 

[FatDaddy]

where would i get these mica pellets?

 

[nmayeux]

I don't know about mica, but an air gap will work just fine. Question is that way down there in Texas, do you need to insulate that box? Mine does just fine without insulation, even in cold weather. The only problem I've heard is about the paint burning off, but my box is coated in oil, so it has seasoned like a cast iron pot.

Tuning plates are the way to go, with the first couple butted up against each other, and a progressively larger gap between plates the further you get from the firebox. Leave them loose so that they are adjustable, and about 8" wide, but long enough so that they sit a little higher than the inlet from the firebox.

 

[FatDaddy]

the reason i ask about the insul. firebox is to see if it will help extend my burn time. so im not constantly feeding it logs.

so put a baffle in at a 45 deg angle then run the tuning plates along some 1" angle iron?

 

[NorthernQ]

I think the easiest way would be to build a steel box around your present firebox. The surrounding steel box can be supported from your present firebox by welding 1" x 2" steel bar on each corner on all sides. Weld the outter metal sides to the steel bar and then weld the sides together. Build the box with the top section last. Before you weld the top section fill the 2" gap between the firebox and the outer box with mica pellets.

I did much the same thing on mine. I used ange iron welded all around, then placed high temp insulaing panels between the angles. Finally, I pop-riveted textured aluminum panels over the outside to protect the insulation. Works like a charm. I can cook a couple of hundred pounds of meat on 40 lb of lump.

 

[BBQchef33]

Im not sure what width your pit is, but heres something to be careful of when tuning pits, less than 24 inchs inchs in diameter.

To ensure the heat gets under the plates, the plates have to be higher than the opening from the firebox. On most <24" inch pits this will put the plates very close to the food grates. Over longer cooks, these plates become very hot and start giving off radiant heat. If they are too close to the meat, you will get a grilling affect.