First build firebox help

[737diesel]

Hey guys, just picked up my 24 inch pipe, cut into 48 and 24 inch lengths. Looks like I should've done my home work first. Calculator is showing my firebox at 150%. Looking for ways to reduce cubic inches, and I have at least a couple ideas. I really like the look of the Millscale option of a recessed flat top on their round FB(I'll try to attach pic), but not sure how to compute the changes in shape.

Also considering adding two plates in a V formation at the bottom of the FB, as in a plates placed from 6 o'clock position to 8, and 6 to 4. These will create some pockets that i could possibly stuff some insulation as well.

I've read a bunch of past posts on this subject, and I know that some say just run it as is and modify if needed. Please gimme some of your thoughts, and thank you in advance.

[Brewmaster]

In my opinion, your firebox will be perfectly fine just the size it is. My daily driver offset is same size, but the firebox is even a bit larger at 27" long (chamber is 24x48, firebox is 24x27) I know many think this is so oversized that it'll be nothing but trouble or at very least, a fuel hog, but it is neither. But also as a point of interest; I lined the bottom of the firebox with the thin fire bricks. I'll look for a photo as an example.

Best of luck with the build!

[ThinBlue]

You firebox size is fine, no worries there. If you have any doubt just look around at what some manufacturers are doing.

This topic will be discussed and clarified soon enough.

[Brewmaster]

[737diesel]

Thanks for the replies, that will help me going forward. I like the fire brick idea.

[Back9Q]

As others have said dont change it. Most FB these days from reputable builders are 140-175% of calculator recommendations


Sent from my iPhone using Tapatalk

[Brewmaster]

Thanks for the replies, that will help me going forward. I like the fire brick idea.

The firebricks seemed to help stabilize temperature swings a bit, at least when burning the fire right on the bottom without use of a log/coal grate, (like the rich and famous do, haha) Speaking of which, I grabbed a fireplace grate to mod and try in there sometime soon, but honestly, it burns incredibly well (amazing food) just on the floor, with the big draft vent down low it's super easy getting clean and hot when you want, so I'm not expecting an upgrade. We'll see.

[Back9Q]

Doubt you will see upgrade. I used basket in my round FB and then went to floor and burns so much better now. I need figure out how keep it on floor in square firebox now


Sent from my iPhone using Tapatalk

[Brewmaster]

Doubt you will see upgrade. I used basket in my round FB and then went to floor and burns so much better now. I need figure out how keep it on floor in square firebox now


Sent from my iPhone using Tapatalk

I'm a fan of the v-bottom in square fireboxes, ala Chud's BBQ

[Dirtytires]

Easiest way to bring an oversized firebox back to proper dimension is either cut off some length in the firebox or put a plate at the top or bottom to block off the required cubic inches.

[ThinBlue]

Just to reinforce what has already been said by a couple other members here, there is no need to "fix" anything unless you find it doesn't work for you for some reason. Your firebox size is just fine as is and being larger might even prove to have a slight advantage for you.

If this was a reverse flow smoker that would be a different story and you would want to stick closer to the calculator.

Again, if you have any doubt just look around at what some of the top names in the industry are doing. Those guys need a roof over their head and aren't in the business of building smokers that people are going to be unhappy with or risk their reputation just to spite a calulator or formula on the web.

The V grate seems like it would be an excellent solution for keeping the splits up a bit off the bottom. I have no experience there, although if I had a square FB I would be giving it a try.