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Featured New Oklahoma Joe Highland - Reverse Conversion, Input needed

PhilHum

Newbie
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Joined Jul 1, 2021
I hear you, and thanks for that. Just trying to get as much as I can right from the start to save myself time later.
Calcs being a good indicator, but not everything. I understand that.

Talking will stop soon, and the real work will begin :emoji_sunglasses:
But first just a couple of other clarification points.

On the flow dam part, I see and it makes sense.
I'm not against dropping the FB at all. I guess this is the flow dam area?

OKJ FB input.jpg


So what you're suggesting is, dropping the FB down quite a bit and maybe going to a half-moon opening?

Thanks on the stack, my guy is pretty good so i think he could manage it without burning through. Will speak to him about the FB input too, seeing him today.
 

PhilHum

Newbie
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1
Joined Jul 1, 2021
PS...Your view from the garden is AWESOME!!!!!!
Thanks yeah, we live in a half-mountainous region, pretty close to a major lake but also a stones throw away the Alps and great skiing.
Warm in the summers, great snow in winters. Life is good here.

This is a mountain maybe 20 minutes from my house, where we went walking in the autumn
IMG_20201108_132058.jpg
 

civilsmoker

Master of the Pit
OTBS Member
2,681
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Joined Jan 27, 2015
I hear you, and thanks for that. Just trying to get as much as I can right from the start to save myself time later.
Calcs being a good indicator, but not everything. I understand that.

Talking will stop soon, and the real work will begin :emoji_sunglasses:
But first just a couple of other clarification points.

On the flow dam part, I see and it makes sense.
I'm not against dropping the FB at all. I guess this is the flow dam area?

View attachment 504961

So what you're suggesting is, dropping the FB down quite a bit and maybe going to a half-moon opening?

Thanks on the stack, my guy is pretty good so i think he could manage it without burning through. Will speak to him about the FB input too, seeing him today.
yup that is the flow dam and if pull and drop the FB yes going with an ellipse (1/2 moonish) shape is what you will end up with...The ellipse shape will remove the losses and make it work much better! The "clean" ellipse area can be that 1.3 the calc and will flow good. I would also consider having your guy add a wider secondary flange (say 3-4 inches wide, above the FB opening ) on the CC side of the fire box just to make the flow path for losses out the lid are longer.

You do realize you are going to have a very nice RF smoker when your done right.......
 
Last edited:

civilsmoker

Master of the Pit
OTBS Member
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3,087
Joined Jan 27, 2015
Thanks yeah, we live in a half-mountainous region, pretty close to a major lake but also a stones throw away the Alps and great skiing.
Warm in the summers, great snow in winters. Life is good here.

This is a mountain maybe 20 minutes from my house, where we went walking in the autumn
View attachment 504964
PS, my 2nd Great Grandfather was born in Scherzingen way back in 1856. His family came over to the US in 1862....
 

PhilHum

Newbie
21
1
Joined Jul 1, 2021
yup that is the flow dam and if pull and drop the FB yes going with an ellipse (1/2 moonish) shape is what you will end up with...The ellipse shape will remove the losses and make it work much better! The "clean" ellipse area can be that 1.3 the calc and will flow good. I would also consider having your guy add a wider secondary flange (say 3-4 inches wide, above the FB opening ) on the CC side of the fire box just to make the flow path for are longer.

You do realize you are going to have a very nice RF smoker when your done right.......
Thanks. FB drop it is then. By flange, you mean a plate extending from the FB/CC inlet into the CC? (on the CC side of course).
I thought about doing that, basically a fixed plate below the RF plate, from edge to edge (from to back and against the inlet) to form a seal and heat channel. I would then seat the RF on this, and with some simple rails on either side. secondary flange and rails would be fixed of course, but I'd then remove the RF plate for cleaning etc.

I'm sure hoping my RF turns out nice, optimism is high!
 

PhilHum

Newbie
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1
Joined Jul 1, 2021
PS, my 2nd Great Grandfather was born in Scherzingen way back in 1856. His family came over to the US in 1862....
I've been there, it's a really quaint village on lake Constance.
That's about 50 miles away from me. Switzerland is indeed a small country, but has a lot to offer.
 

PhilHum

Newbie
21
1
Joined Jul 1, 2021
Thanks. FB drop it is then. By flange, you mean a plate extending from the FB/CC inlet into the CC? (on the CC side of course).
I thought about doing that, basically a fixed plate below the RF plate, from edge to edge (from to back and against the inlet) to form a seal and heat channel. I would then seat the RF on this, and with some simple rails on either side. secondary flange and rails would be fixed of course, but I'd then remove the RF plate for cleaning etc.

I'm sure hoping my RF turns out nice, optimism is high!
Just one thing on the half-moon.
If i'm getting this right; area remains the same as before at 36.86" (1.3 of calcs). diameter entered (1.3 of calcs) 11" gives me a 4.4" height from the top of the FB/bottom of the CC.

It's in the chart below:

half-moon3.JPG


Does that sound about right? Thanks.
 

civilsmoker

Master of the Pit
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This is what I was thinking about to keep it simple and give it lots of area to get a good seal and maybe even a fire rated gasket
OkJoeMods2.PNG



This is the shape I was thinking for the FB to CC
OkJoeMod3.PNG

It matches the "mating" surface between the two circles. It also tells you where to attached the FB to the CC, ie the bottom arc matches the CC arc & the arc height being 4.5 to 5 inches sounds about right

With regard to the reverse flow plate, it is best to have it water tight (ie welded in) with a drain that can remove grease during a cook. You will be surprised on how much grease comes off meat and you don't want that going under the plate and into the FB or area under the plate. you also don't want it pooling up against a lip a the FB joint (hence the shape above). Any grease build up is a potential fire and the increased chance of burning grease creating bad smoke (It will happen at 300degF). If you have a water tight plate with fluid dam opposite to the FB you shouldn't have much to clean underneath if anything. I have never cleaned under mine. This is just me but this is the biggest plus of a RF vs and Offset is the fluid tight plate....it simplifies cleaning big time!
 

PhilHum

Newbie
21
1
Joined Jul 1, 2021
This is what I was thinking about to keep it simple and give it lots of area to get a good seal and maybe even a fire rated gasket View attachment 505010


This is the shape I was thinking for the FB to CC View attachment 505011
It matches the "mating" surface between the two circles. It also tells you where to attached the FB to the CC, ie the bottom arc matches the CC arc & the arc height being 4.5 to 5 inches sounds about right

With regard to the reverse flow plate, it is best to have it water tight (ie welded in) with a drain that can remove grease during a cook. You will be surprised on how much grease comes off meat and you don't want that going under the plate and into the FB or area under the plate. you also don't want it pooling up against a lip a the FB joint (hence the shape above). Any grease build up is a potential fire and the increased chance of burning grease creating bad smoke (It will happen at 300degF). If you have a water tight plate with fluid dam opposite to the FB you shouldn't have much to clean underneath if anything. I have never cleaned under mine. This is just me but this is the biggest plus of a RF vs and Offset is the fluid tight plate....it simplifies cleaning big time!

Thanks.

So I started to put some of this on paper, to be a little better organised.
Working/evolving diagram below

Smoker Plans v1.jpg


It reflects the correct half-moon arcs as in your diagram above.
A question on that, the diameter for the total opening size remains 36.9", so I guess the height becomes 2.25" for top and 2.25" for the bottom arc. Is this correct?

I was also thinking about the FB overnight, and the loss.
I was wondering if I go all out, and do something like this instead;
round FF side door.jpg
round FF side door2.jpg


Basically with a large end opening, I could fuel and maintain, clean etc. I could even seal/weld the top opening shut, and completely eliminate the loss, whilst building in a large enough air intake in the process.

On the RF plate. I hadn't planned to weld it in place, as I thought the weight would provide the seal, but i'm not against that.
I has planned to add sides and ends, to make it a grease trap (like below), with a drain but if i weld in place, don't I run the risk of having grease accumulate between the CC walls and the RF plate sides?
I guess I could have the tops welded flush too, so all grease runs into the tray.

20150606_124612.jpg
 

Attachments

civilsmoker

Master of the Pit
OTBS Member
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3,087
Joined Jan 27, 2015
This should help...
OKMod-sk1.PNG

you may want to make the "gap" height 4.75+ ID opening just for good measure (ie to account for metal thickness). This also shows how the RF plate will just sit nicely in the CC, ie weld around the 3 edges with a 1-2 inch high lip on the far side and its fluid tight (I have a pic of this in the Copper Pot build). Changing your door to the front will fully convert the build to a "new build" as most RF's have the door on the font and not top. Oh by the way this will give you about 10.7 inches above the food grate as shown so large enough for a couple turkeys......
 

civilsmoker

Master of the Pit
OTBS Member
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Joined Jan 27, 2015
Oh the double pie vent works (Shirley Smokers use this), but you don't have the ability to change the lower flow vs the upper flow to tune it. But Shirley smokers don't complain about this.....The double pie is less fab work....and I've thought about using in on future builds.
 

civilsmoker

Master of the Pit
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Joined Jan 27, 2015
Oh one more thought.....If you weld the lid shut and move the door to the front then the side of the CC can be used for the stack vs the back corner.....Just one more benefit to do that.
 

Berettaclayshooter

Meat Mopper
191
98
Joined Jul 14, 2018
I have a OKJ Highland reverse. I ditched the stock tuning plates that were way too thin. I have replaced them with a piece of 1/4" plate steel Mine rests on the side of the CC about 3" below the cook grates, Although I had to bend the front angle flange up to fit it (a lot of work). I also replaced the stock stack as it didn't pull a draft. Mine is made from 3" sanitary tubing with a 90 degree fitting. Total stack is 36" end to center. Also take the stock fire box grate and turn it 90 degrees this raises it up and allows better air flow to your fire. One last thing I did is add tell-true gauges at grate height and used pipe plugs on the factory ports.
 

PhilHum

Newbie
21
1
Joined Jul 1, 2021
This should help...
View attachment 505219
you may want to make the "gap" height 4.75+ ID opening just for good measure (ie to account for metal thickness). This also shows how the RF plate will just sit nicely in the CC, ie weld around the 3 edges with a 1-2 inch high lip on the far side and its fluid tight (I have a pic of this in the Copper Pot build). Changing your door to the front will fully convert the build to a "new build" as most RF's have the door on the font and not top. Oh by the way this will give you about 10.7 inches above the food grate as shown so large enough for a couple turkeys......
Thanks so much, this really helps. Weather here has turned really bad again (we had a Florida grade tropic storm yesterday, never seen that before here). So i'll need to pick this up again once it's a bit better.
 

PhilHum

Newbie
21
1
Joined Jul 1, 2021
Oh the double pie vent works (Shirley Smokers use this), but you don't have the ability to change the lower flow vs the upper flow to tune it. But Shirley smokers don't complain about this.....The double pie is less fab work....and I've thought about using in on future builds.
Yeah i'm wondering if i just put in a simple vent on the top of bottom, to keep that flexibility.
 

PhilHum

Newbie
21
1
Joined Jul 1, 2021
I have a OKJ Highland reverse. I ditched the stock tuning plates that were way too thin. I have replaced them with a piece of 1/4" plate steel Mine rests on the side of the CC about 3" below the cook grates, Although I had to bend the front angle flange up to fit it (a lot of work). I also replaced the stock stack as it didn't pull a draft. Mine is made from 3" sanitary tubing with a 90 degree fitting. Total stack is 36" end to center. Also take the stock fire box grate and turn it 90 degrees this raises it up and allows better air flow to your fire. One last thing I did is add tell-true gauges at grate height and used pipe plugs on the factory ports.
I wish I had a reverse, but it's not available here, so I need to work from a OKJ Highalnd standard, as a base. Yep. I'm going for a 1/4" fixed RF plate, with a lip at the end and a drain, so it becomes by catch tray.
I'll also be dumping the existing stack and going to 4" diameter at around 38" tall. Is yours stainless? looks great in your signature.
 

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