Um... not really. For one thing, there is no Schedule 20 6 inch, you must be thinking Sch.40 or standard wall. The ID should be pretty close to 6. Close enough that it won't matter. The OD will be 6-5/8. The ID will be close to the pipe size, unless it's extra strong, or heavier wall. Pipe sizes change to OD measurements at 14 inch.dacolson wrote: ↑February 2nd, 2021, 2:08 pmCalcs look just fine. You could do 30x30x30 if it's easier on the FB but either is fine.
On the stack, 54" is from the top of the cooker. So whatever the length is from your grate level opening to the top of the tank, add that to the 54" to get your total stack height. That will be a tall stack if you consider the top of your tank will be in the ballpark of 50" or so. 8 1/2' is too tall for a garage so you may consider hinging it or else trying to find an 8" stack. Also, make sure you are using inside diameters of your tank and pipe. For example, a 6" schedule 20 pipe has a 1/4" wall thickness and ends up being is 5.5" ID.
I’ve got a length of 6” 3/8 wall at home. Just re measured. Thought it was 1/4”. Was told it’s sched 20 but I’m no pipe guy. Defer to you on that. ID is 5 1/4”. Point is to double check. It’s a big build. 3/4” difference smaller is almost a foot of extra pipe.hogaboomer wrote:Um... not really. For one thing, there is no Schedule 20 6 inch, you must be thinking Sch.40 or standard wall. The ID should be pretty close to 6. Close enough that it won't matter. The OD will be 6-5/8. The ID will be close to the pipe size, unless it's extra strong, or heavier wall. Pipe sizes change to OD measurements at 14 inch.dacolson wrote: ↑February 2nd, 2021, 2:08 pmCalcs look just fine. You could do 30x30x30 if it's easier on the FB but either is fine.
On the stack, 54" is from the top of the cooker. So whatever the length is from your grate level opening to the top of the tank, add that to the 54" to get your total stack height. That will be a tall stack if you consider the top of your tank will be in the ballpark of 50" or so. 8 1/2' is too tall for a garage so you may consider hinging it or else trying to find an 8" stack. Also, make sure you are using inside diameters of your tank and pipe. For example, a 6" schedule 20 pipe has a 1/4" wall thickness and ends up being is 5.5" ID.
Square tubing works too if it is easier to find. I have seen a few guys turn them 45 degrees (like a diamond) and they look pretty cool.john_az wrote: ↑February 2nd, 2021, 7:38 pmyikes, I had no idea the stack height is from the top of the cooker! yes, that will be way too tall... I will find a bigger ID stack, I might know where i can get some 8"diam thin wall stainless tube....
Im going to build a rotisserie to spin the tank around on to clean it, and hopefully cut the doors tonight.
updated calc. with 8in diam stack ( ID 7.875") so the stack calls for 26.875" tall + 15" (1/2 the diam of the tank to reach cook grate level) so roughly 42" from the top of the stack to cooking grate level... which is going to be at 36" from the ground, so overall height is 6.5 feet tall. Sounds great to me.
I just made my hinges for the doors.. rolled some 1 1/4" x 3/8" flat bar to fit the curvature of the tank, then notched them for the door flange/seal. If I can get the door cut tonight, ill weld them up and report back.
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Actually thats a cool idea, never thought of multi-stacks! This sparked an idea.... I my pick your brain on it, but I have a ways to go until I'm ready for the stack....Dirtytires wrote: ↑February 4th, 2021, 8:53 pmYou left room for the gasket before you welded the hinges on, right? If not, your door has a good chance of binding.
Also, if you already have the pipe for the stack, remember it is total cubic inches that matter. On that big of a pit, you would add a lot of character by putting two stacks side by side....
Ya, no sliding out, I think the door opening is tall enough to make loading the grates easy, really just wanted to make them removable for easy cleaning of grates and inside bottom of tank...dacolson wrote: ↑February 11th, 2021, 10:09 pmHey John, I missed in your pic how you have the grates sitting down into the CC below the door openings. I’m guessing you wont be sliding loaded grates in and out so you can probably skip the grate stops.
Is the pit calculator calling for 4 x 84” inlets and is it telling you that you are at 100% recommended?
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Hey Big T! I was just confused about how i got that number of inlets... i just went back through the calc. and realized i can control that number by putting the size of one single air inlet. brain fart... sorry... i get it now... and Im totally going to do what you did, one fully recommended size inlet per side..... but what about the BF door.. can/ should i add one in the door to give a third option for inlet?Big T wrote: ↑February 11th, 2021, 10:15 pmI'm not sure if I'm understanding your question about the air inlets but you only need 82 sq inches total. I normally put 2 inlets, one on each side and they're both the recommended size so that I can close one side off and use the other if the wind starts blowing directly into the inlet. You want to keep them as low as possible on the firebox so that the air can't bypass the coal bed.
Awesome, makes sense now.....thanks so much for your super-fast response, honestly very helpful, and my material shows up tomorrow, and i just want to knock this out this weekend, so this really helps!dacolson wrote: ↑February 12th, 2021, 12:13 amI’m guessing you put in the measurements that the opening would be 1/4th of the 81 sq in required. You can play around with the size of your openings in the calculator to come up with better options. If that’s the recommended area, you could do two 4x10” openings - one on either side, for example. I have read that splitting your inlets 80/20 helps to add fresh oxygen in the top of the FB to further combust wood gases - improving smoke quality. I did my first pit that way. Not sure it matters. The next 3 are all vented below the grates and burn very well.
Big T’s comment on doubling the vent capacity - 82 sq in on both sides - is spot on. It gets windy here and I’m always closing one side or the other off.