New guy first time builder 250 gallon reverse flow.

[cclark]

Hey guys been looking at the site for a while now. Learned a lot of great things you guys know your stuff. My name is Cody I'm from east Texas area. Me and my grandpa bought a 250 gallon propane tank a couple weeks ago from a propane place and about to try out our hand at this. Grandpa was a pipeline welder so he will be doing most the welding. I will be doing the cutting grinding etc. my tank is 88" in length and 30" in diameter. I googled a firebox calculator and it said I needed 20724 cubic inches. I do not know if all calculators are the same but does this sound right? It comes out to like 27.4" squared. Another question I have is does the baffle plate have to be a certain thickness like 3/16" or can I get away with 1/8"? We plan on starting this weekend and picking up the plate and other supplies Friday. Thanks for the help.

[Rick]

Welcome cclark! - Looking forward to seeing your build...
Mass is your best friend when it comes to the baffle plate so most will recommend at least 1/4 inch - the more massive the steel the better it helps stabilize the heat over time...

The calculations are done by smart smokerbuilders - not me - but they'll be along soon ...

[alleyrat58]

Welcome cclark! Can't wait to see your build! Take lots of pics for DCMAN the "photo czar."

Frank is the guru when it comes to calculations, but off the hip you sound close. I believe the volume of the stack will be of more importance.

I will echo Rick's comment about the baffle plate - go big or go home - LOL. I just put a baffle plate in my smoker, 1/4 inch, and definitely would not go less than that if I had to do it over.

[cclark]

Ok well in that case I may go with 1/4" firebox as well. I'll be sure to post pics of progress.

[Smokeone]

Welcome cclark!
Calculations are not me either, but I think you are close.
I would go with 1/4 for the baffle and the firebox (if it is not insulated). That is just my .02.
Good luck, and dont be scared of DC he is a creampuff.

[cclark]

Thanks guys for the help will be picking up a 1/4"plate tomorrow or friday.

[RDRASH]

Baffle plate should be no thinner than 1/4, firebox should be roughly 1/3 the volume of the cook chamber. Oh take lots of pics or

[dcman (The Czar)]

..... .....and I will be watching....

[k.a.m.]

Welcome to the site cclark. Your tank size hits on the calculator but your firebox comes in a little small at 27.4. Personally I would increase to 28" square but I like slightly larger fireboxes.
1/3 volume of your tank is 20724.00 while a 27.4 square firebox is 20570.82. A 28"
square firebox will have a volume of 21952.00.
With the 28" firebox the ff/cc opening needs to be 175.62 Sq.in. A half moon of 21.5" x 10" 3/4" will give you an opening of 181.5 Sq.in. The added room will allow for a grease bridge on the bottom to keep accidental overflow into your firebox.
I would use 1/4" minimum for my R/F plate.
Make sure you leave at least your firebox to cooking chamber opening at the opposite end of the of the R/F plate so no bottle necking occurs.
I would add a secondary drain in the lower chamber for clean out.
I hope this helps.

[cclark]

yea i was probably gonna round up to a 28" firebox...a little extra cant hurt. When you say a "A half moon of 21.5" x 10" 3/4" will give you an opening of 181.5 Sq.in" Im assuming you mean 21.5" wide and at the highest point being 10" tall? Just trying to get all this right before i begin. Thanks again