First Smoker Build - Firebox Advice

[Chuck_NE]

So I jumped in the deep end and bought myself an old 500 gallon propane tank and have drawn up plans to convert it into an offset. Feeling pretty good about everything except I'm not sure how big to make the firebox. I'm sure I'll need a decent size fire to heat this bad boy up but I don't want to overdue it.

Right now I've got the inside dimensions of the box at 18 x 27 x 18. Think that'll be sufficient to bring the cook chamber up to 300? I do plan on lining the box with fire brick.

[Q Junkie]

I think this is what you need.
http://www.feldoncentral.com/bbqcalculator.html

[Diesel Dave]

According to this calculator you're going to need 38,500 cubic inches.
http://www.feldoncentral.com/bbqcalculator.html
You are only at 8,748 right now.
So your box is too small. That is a very large area to heat up and it's going to take a big fire

[Diesel Dave]

:laugh: you beat me to it!

[Chuck_NE]

Looks like I need more steel...thanks y'all

[Chuck_NE]

Good news is I got the chimney dia & length right :-D

[Chuck_NE]

That's a damn big firebox...maybe I should scale this down a touch

[Diesel Dave]

Yeah it's big but consider the size of the cooking chamber. There's a lot of space, not to mention steel to get up to temp and keep it there.

Congrats on getting the chimney right, that is a very important. :thumb:

[Chuck_NE]

Ya I'm going to scale the chamber down to 60" x 36". That makes everything more reasonable, and saves me some money on materials. Trying to keep this build around $1,000.

[Bludawg]

FB should be 1/3 the tanks volume to draft properly. Plan it right use Feldons pit calculator.

[SmittyJonz]

500 gallon is LARGE. I find 150 gallon size perfect but many like 250 Gallon size - which is Big.

[SmittyJonz]

Here is a 500 gallon smoker with proper size FB.

http://www.bbq-brethren.com/forum/showthread.php?t=212017

http://i1326.photobucket.com/albums/u645/bobjones79/C11B9C6B-851C-4B75-922F-96B745CB68D4_zps0lkcmimf.jpg (http://s1326.photobucket.com/user/bobjones79/media/C11B9C6B-851C-4B75-922F-96B745CB68D4_zps0lkcmimf.jpg.html)

[Chuck_NE]

How much wood do you need to heat that bad boy?

[JohnnyB]

You going to keep it traditional or go the reverse route?

[Chuck_NE]

Traditional

[Chuck_NE]

Got the inlet and door cut today. Hopefully have her finished up in a couple weeks. Will have some photos up soon.