24 x 46 RF Patio Build

[Pete Mazz]

[SeenRed]

New question:

What is your go-to method for cutting the CC door into the tank without warping? My tank is 5/16" wall thickness. The tools I have at my disposal are a plasma cutter, cutoff wheel/angle grinders, a jigsaw and a reciprocating saw. Also f it's the best method, I'm open to purchasing a metal cutting circular saw, like this one:

https://www.amazon.com/dp/B08287HSJL/?c ... _lig_dp_it

My original plan was to cut it with my plasma cutter, but now I'm wondering if the heat of plasma cutting will increase the chance of warping the door. One of the builders whose Youtube videos I've followed said that the risk of warping is reduced by using a dry cut circular saw. I understand that, no matter how I cut it, there's a chance the door might spring if there is tension in the steel...but I'd like to eliminate any variable if I can.

Hoping I can rely on yall's experience again...

Red

[Dirtytires]

I ran a plasma cutter on mine...it is 0.25" thick...and had no issues. I was conscious of the heat in the metal and careful not to put too much in. Make short cuts and give it time to cool and you will be just fine.

[SeenRed]

Well thanks to Dirtytires' advice, I got the door plasma-cut this morning.

I'm not disappointed with how it turned out - not precision cuts, but not too bad...

So my plan now is to tack the top and bottom flat bar flanges in place, then finish the side cuts with a cutoff wheel - so I can remove the door and start rust removal inside the CC.


This leads me to a new question. What is your preferred size of flat bar to use as door flange? Frank's plans call for 1/4" x 2". I suspect that 1/4" flat stock is gonna be difficult for me to bend...and seems like overkill for a piece of trim. I decided I might try 1/8" x 2"...but I looked through my steel rack this morning, and I don't have any. I do have some 1/8" x 1 1/2". Do ya'll think I need to make a run to the steel yard for 2" flat bar? Do you think 1/8" thick is heavy enough...or should I go with 3/16" or even 1/4" ?

What do ya'll find works best for you?

Thanks again for any experience you can share!

Red

[Big T]

1/8'' is great for door flanges and 1.5'' is plenty wide enough as long as it covers your gasket material.

[SeenRed]

1/8'' is great for door flanges and 1.5'' is plenty wide enough as long as it covers your gasket material.

Appreciate the advice T!

While I haven’t technically gotten that far in my planning, I’m sure I’ll use one of the black adhesive gaskets like LavaLock or something similar. As long as I can find it in 1/2” - or maybe 3/4” - I should be good to go with the 1 1/2” flange.

Thanks again Big T!

Red

[SeenRed]

Got the door cut, and a flange tacked on top and bottom, then removed the door so I can start cleaning up the rough edges of the cut and removing rust from the CC interior.

I took Frank's recommendation and picked up one of these surface conditioning tools. It made it surprisingly easy to remove rust from the interior surfaces of the door and CC.

So a new question...regarding the smoke stack: Frank's plans call for a 24" x 4" id pipe. I decided to go with 4 x 4 square tubing instead of round pipe - mostly cuz at the time I thought it'd be easier to make a square cutout with my plasma cutter than buying a 4" hole saw. So I've done the math with the conversion calculation I got from one of Frank's email newsletters. Please double check my calculation here and tell me if this sounds correct.

The formula for finding the length of square tubing needed is:

Volume of the round pipe (π x Radius squared x height) divided by the area (length x width) of the square tubing.

The volume of the round pipe is: 3.14 x 4 x 24 = 301.44
The area of the square tubing is: 4 x 4 = 16

So...The height of the square tubing should be 301.44/16 = 18.84"

Does that sound right? Roughly 19 inches? Seems a little short. I bought a 4' length of 4x4 sq tubing. On a reverse flow, what impact would it have if I made the stack longer? How much longer do you think would be too long?

All this makes me wish I'd just stuck to exactly what the plan called for, and bought a length of 4" pipe or round tubing.

Anyway...thanks for any advice ya'll can give me on this.

Red

[Barrion2018]

I'm still new at this, so take what I say with a grain of salt.

I made a RF a couple months ago and made the stack taller than what the calculator said it should be. I also put a damper on it. It works great.

Like I said I'm still new at this, but if it were me, I would go taller than 16" above the CC.

Your build looks great, can't wait to see it when you're done!

[Pete Mazz]

Volume of the round pipe (π x Radius squared x height) divided by the area (length x width) of the square tubing.

Due to friction loss when using a rectangular stack, this will calculate the equivalent size of a round stack with the same airflow.

[Dirtytires]

No need to make it longer than the calculator calls for. It just adds needless top-heavy weight and looks goofy. It can also affect the operation of your pit as proper combustion and airflow depends heavily on the proper sized stack. As mentioned, you could make it longer and add a damper but that just seems like a lot of work just to get back to where you would be with a proper length stack in the first place.

[SeenRed]

I'm still new at this, so take what I say with a grain of salt.

I made a RF a couple months ago and made the stack taller than what the calculator said it should be. I also put a damper on it. It works great.

Like I said I'm still new at this, but if it were me, I would go taller than 16" above the CC.

Your build looks great, can't wait to see it when you're done!

Thank you sir! I'll probably put a rain cap of some kind on the top of the stack, but I'd prefer not to mess with a true damper if it's not necessary.

Red

[SeenRed]

Volume of the round pipe (π x Radius squared x height) divided by the area (length x width) of the square tubing.

Due to friction loss when using a rectangular stack, this will calculate the equivalent size of a round stack with the same airflow.

Screenshot 2022-10-18 at 03-34-32 Online calculator Square Stack Calculator.png

Thank you Pete!

So - forgive my density - according to that calculator, my 4x4 square stack should be 20" long...correct?

[SeenRed]

No need to make it longer than the calculator calls for. It just adds needless top-heavy weight and looks goofy. It can also affect the operation of your pit as proper combustion and airflow depends heavily on the proper sized stack. As mentioned, you could make it longer and add a damper but that just seems like a lot of work just to get back to where you would be with a proper length stack in the first place.

Thanks DT...that's just what I was asking about. I don't want to screw up airflow or proper combustion. And I definitely wouldn't want the stack to be longer than the 24" that's in Frank's plans. I agree that taller stacks are cumbersome and clunky.

I was mostly just trying to get someone to validate my calculations so I don't end up with a stack that's too short.

Red

[Pete Mazz]

20" is calculated but I wouldn't be afraid to go to 24".

[SeenRed]

20" is calculated but I wouldn't be afraid to go to 24".

Thanks again Pete! 24" is the number that was originally in my head - since that's the height of the round stack that Frank's plan calls for. I definitely wouldn't want to go any taller than that.

Red

[SeenRed]

Well progress has been slow because life gets in the way. But I was able to spend some time in the shop this morning. Spent most of that time with a grinder and my surface conditioning tool, cleaning up plasma dross and surface rust in the cook chamber and on the CC door.

Then I got the cook chamber door all framed out.

Did a test fit just to see how it fits, and if I have any door-warpage. Overall I'm pretty happy with how it fits now.

I don't plan to install the hinges until after the baffle plate goes in...might even hold off on mounting the CC door and hinges until most the other fab work is done.

Hopefully tomorrow I'll get started on getting the baffle plate installed. Had to get a little technical assistance first from Frank on the BP design (Thanks Frank!)

This project has gone pretty slow, but so far, no big snags or problems yet (knock on wood!).


More to come...
Red

[Dirtytires]

Keep at it....looks really good!

[SeenRed]

Keep at it....looks really good!

Thanks man! Worked on getting the BP ready to install this morning…but realized I gotta make a run to the steel yard for a few odd and ends, and gotta get a 1 1/2” hole saw to cut the drain. Also ran out of shielding gas, so I’ll also have to make a run to the LWS.

Always something…

Red

[Barrion2018]

Very nice work! Can't wait to see more.

[Big T]

[SeenRed]

The holidays kept me busy enough to prevent posting updates, although work on the smoker has continued slowly but surely. I hope everyone who still comes around had an enjoyable holiday season and a happy new year!

One thing that slowed my progress was my mig welder crapped out in early December. Main board fried, and it was a chinesium machine, so it was gonna be more trouble and expense to fix it than it was worth. So I had to go buy a new welder.

It's Lincoln's newest mig machine - a POWER MIG 211i.

Another "detour" from the smoker project, I was tired of tripping over my grinders all the time, so I took an afternoon to fab up a rack to store them on. I was happy with how it turned out.

Back to the smoker build. After getting the door about like I wanted it, got the baffle plate and the drain pipe in, and tacked it in place.

Then tacked the end plate in place - so far the fit up is very acceptable.

Fire box tacked up.

Gonna work this afternoon on finishing the weld-out on the FB, then I think I'll be ready to stick it all together and see how it fits!


More to come...

Red

[Big T]

Nice!! All of it!!

[Pete Mazz]

[Barrion2018]

Looking good!!

And I love your new welder!

[Barrion2018]

Looks like you have a nice shop to work in too.

I’m jealous. I have to work outside, no shop.