Fire Box Size help

[tpilews]

Hey guys, I've got a question about the height of my fire box. I'm going to build the fire box on the side of my old 3-burner Weber Spirit grill. I want it to look as "stock" and unmodified as possible. The grill itself has volume measurements of 20" tall x 24" length x 17" wide. The grill tapers towards the bottom to 14 3/4" wide below the burners, so I set that for my fire box width. The frame that holds the grill also comes out to hold a side table. That part comes out 13 1/2", so I set that for the fire box depth. Now, according to a calculator I downloaded, in order to roughly get 1/3 the size of the cooking chamber for the fire box, the height I chose was 6 3/4". Now is that tall enough to provide enough air underneath, while giving enough room for the fire?

Here's a picture of what I'm basically dealing with:
Sorry for the crude photoshop of the fire box.

 

[deltadude]

I haven't looked at the weber spirits grills, I have an older weber genesis silver b. Under the genesis is a slide out bottom tray, which has the drip hole and the drip pan under the drip tray.

Here is what I had thought about doing before buying a dedicated smoker.

Buy a weber smokey joe.

You can go two ways, 1st the smokey joe only provides smoke, and a gas burner provides heat. 2nd way, the smokey joe provides both the heat and smoke..

Either way you will need a flat plate sized to the slide out bottom tray opening and then cut the size of round opening in that plate. How big the round fitting is depends on you choice of how to use the smokey joe. SJ as main heat source 6 to 10 inches, SJ as smoke only 3" should be enough.

You will have to cut an appropriate size hole in the lid of the SJ. You can use alum. flex pipe to con

You could try to use the slide out bottom tray mounting rails to slide in the adapter, so you don't have to deal with removing the burners every time you want to smoke. But that will present challenges on making an air tight fit.

You can get a Smokey Joe for $20, I have seen them given away on the Freecycle Network.

 

[graybeard]

I don't like the idea BUTT go luck. I will be looking forward to the finished product as well as how it functions.

beard

 

[deltadude]

If he does the mod the way I explained, there is no cuts or changes to the original BBQ.

I have seen a youtube video of something similar to what I explained but it was with a char broil gas grill or some other similar model. The guy plugged all the holes with alum foil, it looked like it did an adequate job.

 

[tpilews]

Thanks for the idea, but that isn't the look I was going for. I don't want to do a dedicated smoker because I don't have the room for two grills. There is more than enough room on the side of the Weber to add a fire box. The only problem I foresee is sealing the cooking chamber adequately.

Anyway, after much thought, I'm going to extend the height of the fire box to 12". This will give me more than enough room for a slide out ash drawer and to build a proper fire.

 

[tpilews]

Update with some progress...

Frame (I decided on the final dimensions of 12" tall, 12" deep, 15" wide)


Hinges (3/8" ID)



Still waiting on the steel plate. Going to finish up the hinges today or tomorrow. Need to add the firebox to cooking area opening.