RF build problem

[weev]

Hey guys I have a problem and im not sure what to do so here it is
I started a rf smoker build before I found this site and now that I have been on here I find these pit calculators and I dont believe my fb is big enough
I dont have my project done yet but my cc and fb are already welded together and im not sure if I should cut them apart or what to do
my cc is half a propane tank 36" wide and 48" long and my fb is 24" x 24" x 20" with a warming box on top

 

[urbotrimmm]

Nothing worse than not enough heat.  How much too small are you?  Is it possible to cut the back side out and extend the Firebox?

 

[weev]

Oops wrong button I wasnt done yet

feldons said im only at 80% so where should I go leave as is knowing I will go threw more fuel or should I cut the bottom out and make the fire box deeper ? Any ideas

 

[urbotrimmm]

My firebox is calculator size and way easy.  I would be tempted to tell you try and see.  The person who really knows is Ribwizzard.  Try private messaging him and see what he says.

 

[dockman]

That box certainly seems big enough but the calculator don't lie! I would try it what's the difference if you enlarge now or later?

 

[lendecatural]

If it's all welded together, cutting off the bottom of the box and extending it is about your only option. I agree with the guys, fire it up and see how it does and make sure you have your vents low and middle so you can push more air through with the upper vent. Will you be smoking in cold weather? That may make a difference.

 

[weev]

I do live in michigan so it does get a bit cold
I also be pushing air with the bbq guru pit viper
and fixing now vs later it would be easier now considering I dont have the frame or door done yet
I guess one other thing I could do is add to the front and make the fb stick out further than the warming box any ideas on that I think that might be easier than cutting out the bottom

 

[lendecatural]

If you are going to run it with a fan, that changes all the air dynamics of the box for the better. If you could get your hands on some 2x6 angle and make a frame around the door to extend it out by the 6" dimension, you would have good volume numbers and a flat surface to mount your door against.

 

[weev]

That would add to it but I would still be under size according to the calculator I would have to add at least 10 inches to be at 100%

 

[urbotrimmm]

I agree with Len.  Fire that puppy up before you paint.  Try her out.  Only thing you lose is a day.  You may just find it does what it's supposed to and you are worrying for nothing.  20% is not that much.

 

[smokejumper]

If you are using a guru, that changes everything.

Feldons calculator is based on observations of pits that work well.

But those pits were all naturally aspirated (no fan).

My intuition is that the guru will help overcome the undersized firebox, since you are not relying on the draft to stoke the fire.

I would try it as is first, and only modify it if you have problems.

 

[lendecatural]

Yeah, go with what you have, then if the cold weather is too much for the cooker, you can always section it behind the door and add flat bar to expand it forward. I think you will be good with 80%.