Starting build today!

[gijsveltman]

Hello,

I'm (finally!) starting my build today and I'm really excited. It's a 60 gallon propane tank, so the Calculators (awesome, btw), say I need a 17x17x17 FB. I'm using 4 inch round tubing for the chimney. My biggest question, though, is the FB to CC opening. From what I understand, the cut-out height, and the top width of the cut-out, I should cut into the tank until I reach the "flat" part, by this I mean to the point where the ends are no longer round? I don't know if I am explaining myself correctly. How "deep" into the tank does the FB go? How do I measure the width, height, etc, if it is a rounded end? This is the tank I'm using:

Thanks in advance for the help!

[Dirtytires]

Is it a reverse flow? If so, the top of the firebox is at the same level as the baffle plate...that takes care of the height. The depth should be minimal but enough to get your required opening. To measure the opening. I would not measure the opening on your tank but just notch it out. The opening can be much more easily measured and cut on your firebox.

[gijsveltman]

Thanks! It is not a RF though, but a standard offset. Would that change anything? I'm still confused!

[Dirtytires]

I'm sure someone will be along shortly with better info. My only experience with a traditional offset was a store bought unit.

What is the dia of your tank? Let's just assume it is wider than your 17 inch firebox. I would fab the firebox and cut the proper square inch opening in the top back of the firebox, starting about an inch from each side and making it as wide and narrow as possible to get the right size.

The traditional offset has the disadvantage of having a hot-spot in the cook chamber right next to the firebox. On mine, the first 1/3 of the cc was actually pretty unusable. Therefore, the firebox needs to be as low and as far off to the side as possible to help minimize heat transfer.

Now that you have the hole in the back of your firebox, I would position it so that the bottom of the hole is about 1 -1.5 inches above the cc floor (to act as a grease dam) and inset it only as far as needed to get a good weld and the look you want. You could cut back past the curve in the take or use the rounded edge to give it character. Either way, use of cardboard templates and cutting a little at a time is a good idea.

[Cole]

Trying not to complicate things but if its in your budget I would make it a reverse flow. Keep us posted. Take your time and plow thru this site pretty much every question has been asked.

[bswisher]

I would agree on making it a reverse flow. I just finished a 60 gallon reverse flow using almost the same tank you have. Mine works AMAZINGLY well. You really aren't looking at much more $$ to go reverse flow. Here is a link to how mine turned out and how well it performs. viewtopic.php?f=11&t=6342

[Big T]

It's hard to beat a RF for the even temps in the CC but the calculator is the same for a traditional offset and a lot of guys like the different temp zones.

[gijsveltman]

I wanted to start with a standard offset to start with the basics. I'm planning on building another one later this year. Would the temperature difference be very noticeable in a smoker this size, even using a baffle plate on the opening between the CC and FB? Now I've got doubts, but I really wanted to start with a standard offset!

I'm have no experience in this type of work, so I apologize in advance for any dumb questions, and appreciate all the help I can get.

[Big T]

There's no such thing as a dumb question around here, trust me on that one. If you put a baffle at the throat for the first 25%-30% of the CC with a few small evenly spaced holes in it, then it should really help out. There's nothing wrong with the standard offset, it'll take a few cooks to figure out the temp difference but it'll get easier the more that you use it.

[Squiggle]

[The Czar]

If you build a offset now...you’ll just have to build a RF later...lol!!!


Sent from my iPhone using Tapatalk Pro

[Pete Mazz]

You could build a hybrid by using stacks with dampers on both ends. Slide the tuning plates together for a RF.

[gijsveltman]

Thanks for your help. I am still very confused as to connecting the FB with the CC. The calculators give me the following data:

But my tank is not cylindrical, it has rounded edges. Do I make a rectangular cut on the FB, and then translate that cut to the CC? Because the throad calculator makes it appear to have a rounded edge on the right and left sides. I don't know if I'm explaining myself correctly?

[Rodcrafter]

What shape is your CC you said that its not cylindrical butting is 60 gallon?


Making memories!

[gijsveltman]

It's coming along beautifly! I figured out the throat problem, and we're attaching it later today!

[Hogpit]

The cutout in the firebox isnt important as the space below your RF or tuning plate will determine throat area.

[gijsveltman]

The cutout in the firebox isnt important as the space below your RF or tuning plate will determine throat area.

Draft1.jpg

Thanks!

[gijsveltman]

First fire today, to see how it performed. Door is a little leaky, so I'm going to order some gasket to install. I also noticed it was hotter near the exhaust than near the firebox, which I found odd. I don't know if it has something to do with the fact the grease drain is near the firebox and missing the plug, it's just and inch-and-a-half hole right now, so there could be some heat drain. Or maybe the baffle we installed is too long. I also noticed that some smoke came out the firebox door (I plan on cooking with the door open), and I don't know if it is because it is not pulling properly as it still has some leaks and holes, if this is normal, or because it was really green wood belching out lots and lots of white dirty smoke. I didn't have time to go home and change, so I'm at the office with a real heavy smoke aroma right now!

Later today we're painting, installing the thermometer and wheels. And I think we may be done, aside from the gasket which I have to order, and don't know how to install!

Can't wait to try it out!

[Hogpit]

Having the exhaust outlet in the middle of the cylinder could be affecting the draw, also will add to the leaking from the door as the smoke accumulates at the top, above the exhaust. The high heat at exhaust end could be unlevel cook chamber?

[gijsveltman]

Having the exhaust outlet in the middle of the cylinder could be affecting the draw, also will add to the leaking from the door as the smoke accumulates at the top, above the exhaust. The high heat at exhaust end could be unlevel cook chamber?

I hadn't thought about that! It will be level once I get it home, here it is a little uneven.

Thanks!

[Dirtytires]

It’s not going to draw properly with the door open. All your heat is going out the door. That will also prevent you from controlling your fire and getting a thin grey smoke.

Only a small amount of heat will actually run thru the smoker since most is out the door. What does is probably getting stuck at the top of the smoker as it has no where to go with the exhaust being low on the cc. Without proper airflow your heat will be unpredictable. A solid baffle plate is only used in a reverse flow. I would think you would want a tuning plate/adjustable plates to eveningly distribute the heat.

I would hold off on paint till you get it dialed in. Sounds like more welding is needed like some air vents low in the firebox and possibly a stack move. It’s all fixable and to be expected on a custom build.