Reverse flow stack size confusion - new builder.

[dkjonesau]

Hi guys

New member from Australia. Hi!

Sometimes lots of information is great. Sometimes it adds to the confusion [emoji23]

Nearing the end of my first build & getting to some finishing details. I initially started with Feldons calculator a month back, before discovering this group a week back after watching Primitive Pits Quetorials episode on Feldons calculations.




Running my plan through Pete’s calculator I get a smaller throat size. (I think there’s an issue with Feldons circle segment calc for the area too, it’s depth of throat half moon was way over 40sq in.)

I’ve got a baffle plate that I could extend to get the 40sq in down to 26 if I need to.

On the stack I was looking at 4” or 6”.

Based on Pete’s calculator either 14.4” for a 4” stack, or ~9” for a 6” stack. Either seem really short. Aesthetically I’d like higher.



Feldons gives me 20” for 4 in stack or 9” for a 6” stack.

Link to BBQ Pit Calculator

How much difference will stack height make?

Happy to go taller & put a damper on the top if it’s going to draw too well?

Thanks

Dave

[dacolson]

First of all, Welcome! Glad to have you.
Second, I would recommend that you follow one calculator or the other, not pick parts of the sizer from one and parts from the other. I’m not certain but I’d guess Feldon’s larger throat contributes to the taller stack recommendation.
That said, if you like a taller stack, make it taller. You can always cut it back a little if you are having a hard time controlling temps.
Finally, nice looking pit. Those wheels look great. Can’t wait to see your first cook.

[Pete Mazz]

On Feldens you entered a larger FB. On ours you need to adjust it as you're too small.

[dkjonesau]

On Feldens you entered a larger FB. On ours you need to adjust it as you're too small.

Ah.. Yes. I put the depth with the grated in this one. At 70cm x 38cm (dia) it's 27.55 in x 15 in.

The Feldon's measurement is closer to the actual size. Just the bottom of the FB is an ash collection area. Guessing it still counts in volume.

DJ

[dkjonesau]

Hi Pete
This is probably closer to actual.


Wasn’t sure whether or not to include volume under FB grate in FB size?
DJ

[dacolson]

Use the actual size of the FB.

[Dirtytires]

I have never used Feldons so cant speak to its accuracy. I know his calculators are used a lot so can’t imagine them not working. I have seen many, many pits built here using our calculator and can attest to ours working perfectly. The numbers will be different from both so you will need to make the decision as to what you are going to use and stick with it.

Your measurements also need to be accurate. The firebox volume is the entire firebox.

Chimney is determined by volume. The calculator will give you a specific volume and you can decide what height you want based on the diameter of the pipe you use. The general consensus is to put the exhaust height just high enough to keep the smoke out of your eyes but no set rule, so if you want it high, Just use a 3 or 4 inch pipe. A damper is nice to have but still start with the proper sized chimney.

Can’t tell from the picture so I just have to ask....is the firebox galvanized?

[towtruck]

Welcome!

Off topic question for you.......are any of your tanks galvanized on the inside? If they are you will need to burn it off the inside. The exterior coating won't hurt much but any galvanized interior areas will slowly burn off and contaminate your food....especially if the fire box is lined with it.

[dacolson]

Not to mention you need to wear at minimum P2 filter respirator or you can get super sick welding on it.

[dkjonesau]

Hi guys

No gal on the inside of the tanks so all good there.

Still needs a bit of finishing work, drain, handle, wood rack, workbench & paint but I finished it to the point I could test fire it Sunday. All seems to work. Will need to play with inlet & damper to learn temp control but the temp was even one end to the other by a few degrees.

Leaked a bit of smoke around cook chamber door until it got going, then was fine after I got enough temp & clean smoke. Been an interesting project. I’d definitely make another.

Heap of pics during the build on my FB page link to FB page with pics

I’ll upload some pics when I’m no on my phone.

Cheers

Dave

[dacolson]

Just checked out your pics. Nice looking set up. That’s a cool looking stove too. I love shop food cooking.


Sent from my iPhone using Tapatalk

[Juliediane]

I want to know about the reverse flow smoker. can anyone suggest to me the best reverse flow smoker?
offset smoker

[Dirtytires]

I want to know about the reverse flow smoker. can anyone suggest to me the best reverse flow smoker?

Please start a thread, maybe under ‘introductions’ and give us a little more information. What is your experiences both welding and cooking, what are your needs in a smoker, what are your expectations? We are happy to help and look forward to seeing your post.

[tinspark]

I want to know about the reverse flow smoker. can anyone suggest to me the best reverse flow smoker?
offset smoker

Your question is a little vague. Are you planning on building one? Or are you asking so that you can buy one?
I think you may be asking about the differences between an "offset smoker" and a "reverse flow smoker.
Here is a Podcast from one of the "Big Guns" here on this site. He explains the advantages of both smokers.
And hot and fast cooking opposed to low and slow cooking.
https://audioboom.com/posts/7687157-sho ... r-low-slow
You will never find total agreement on which way is best, It all depends on the pitmaster, what they have been using and the stories that they tell.
I prefer my true reverse flow with the continuous baffle plate, but I am starting to really like my GF...

[SheffSmoker]

I'm detecting a bad attempt at spam hidden in a question, only they can't do hyperlinks correctly. 2/10. See me.

[Big T]

I also believe it was attempted spam but the link didn't come through in the post. The member was warned so if you see it again just flag it and someone will handle it.