Tuning plates -- good , bad , or ugly ?

[Smokin Okie]

What's the consensus on tuning plates ?

Not many smoker builders sell their units with tuning plates. The only one I know of is LSG's 24" pipe smokers. They include tuning plates with instructions on where to place them.

If ya can't tell, I'm on the fence with them. I think they can evenly distribute heat, but they can also influence flavor with the smoke created by juices dripping on hot metal, much like a reverse flow.

They can also restrict air flow, but more and more I'm coming to the opinion that air flow is not important in a backyard cooker. Yeah, on a 14 foot long , 1000 gal propane tank cooker, air flow is important. But I think most of these small smokers with 36 to 48" cook chamber , don't need a lot of air flow.

I'd been really proud of my Old Country Brazos, I thought I'd finally figured it out on getting even cooking temps end-to-end ......... and then I did a biscuit test and found out where my heat was at. The biscuits were done more thoroughly on the FireBox end of the grate, but not by much, even if my temp gauge said the temps were even. But then I turned the biscuits over ........ and the ones close to the FB were far more done.

Anyway, I'm thinkin about tuning plates. Welcome all opinion ?

 

[Smokin Okie]

Results of my biscuit test. I had to recreate the bottom of the biscuits. I only took a pic of the top side and later made a pic of the bottoms.

And not to let a good fire go to waste, I threw some sausage on. I'm gonna put my tuning plates in and do another biscuit test and use more biscuits.

 

[flatbroke]

Never used them before. Look forward to seeing your findings

 

[kruizer]

I put tuning plates in my Oklahoma Joe Highland and was able to change a 30 degree difference from end to end to about a five degree difference with no real change in smoke or air flow

 

[daveomak]

You already had 1 HUGE aluminum foil tuning plate in the smoker.....
The biscuit test showed it worked as designed.... moved all the heat and smoke....
Great test....

 

[Smokin Okie]

You already had 1 HUGE aluminum foil tuning plate in the smoker.....
The biscuit test showed it worked as designed.... moved all the heat and smoke....
Great test....

No, that foil is lining the bottom of the cook chamber just to make cleanup easier. I always put that down. But I am thinking about adding water to the bottom of the cook chamber instead of using a water pan. Just thinking about it , though

BTW, a while back you may recall, I posted about using digital or analog gauges because the readings I was getting between the two, were way off. Your advise was to use the analog gauge, which I've been doing. But I think I've solved that mystery.

A while back, I put gaskets on my cook chamber door. The gasket across the top of the door, keeps the door from closing completely, it leaves a gap along the bottom of the door. I wasn't concerned about that because heat rises and in the past I've run my digital temp probe wires out the bottom of the door, creating a gap.

But look at the biscuit test, the biscuits along the bottom of the door aren't as brown. And they were more doughy than other biscuits. And the biscuit that got done the least , the one in the lower left corner, was right where I put my digital temp probe. I think you can see the clip that holds the probe in that pic.

I have no doubt that gap along the bottom of the door causes those temp differences. I'm taking the gaskets off. They're more problem than they are worth.

I smoked yardbird two days ago. I put the digital temp probe on the other side of the grate, as far away from the door as possible, and I got readings that were in line with my Tel Tru gauge.

 

[Chasdev]

I drove an old country for a few years and got some good results, also some bad.
The firebox end will always be hotter, that's the nature of the beast no matter what you do to it.
I did find however that extending the exhaust stack three feet helped as well as removing the ledge where the exhaust is welded to the left side.
Also, running without the fire grate (like Franklin does in his Old Country smoker as shown in his home cook videos) allows a slower fire and better banking of coals rather than a fire that wants to run away and coals that get hotter and hotter with increased air flow and velocity.
Best plan is to create "mini-splits" about 12 inches long by 3 or so inches in diameter and as much as possible, stand them on end or form a standing triangle so they burn very slowly with flames licking gently up the sides.
Fire creates the smoke which flavors the meat, coals create the heat with which we burn briskets.

 

[Smokin Okie]

I've never used the factory FB grate. I'm now using an LSG fire basket, that does work great.

Did you try tuning plates ?

 

[Chasdev]

Yes, I tried solid plates about 6 inches wide which I could slide around to different places and deploy different openings between plates.
I also had some with holes ranging from small to large which I could move about.
I found that while it did move the heat towards the exhaust end, I did not like the radiant heat doing all the cooking rather than the hot smoke.
Or rather that when the fire was first started they worked great but a few hours into the cook they got as hot as the firebox end and sort of baked the meat.
I ended up with two water pans, one at the opening from the firebox and one under the meat and added water to the firebox end as it boiled dry.
Also, I leave more fat in place and cook fat side down 3/4 of the way toward the exhaust away from the fire.
Now that I think about it, there are several stages to a cook and each needs different tweaks.
New fires and early cooks were a breeze with temps well in hand (275) but as the entire smoker heats up and the sun starts to bear down on it, temps want to rise and fire management becomes more intensive, at the end of the cook fire management becomes very tricky and temps want to run away requiring almost constant tinkering using very small chips of wood to try to prevent overtemp.
Or maybe it was the 12 beers I drink during the cook?

 

[Smokin Okie]

Yes, tuning plates do turn the smoker into a version of a reverse flow, where radiant heat becomes a factor. And juices dripping down on the plates create a different flavor.

I can get temps even end-to-end measured by the temp gauges. But what I think is direct heat from the FB is another story. What concerned me from the biscuit test I did, was the under side of the biscuits, not the top half, they were far more done on the bottom, in fact, a couple were burnt. I think that's gotta be direct heat.

A longer FB, allowing the fire to be further away from the cook chamber would help. The LSG fire basket helps in that regard, its 12" long and I move it all the way to the door, creates about a 6" buffer between the fire and the cook chamber.

But there's gonna be wasted space at the FB end of the cooking grate of any offset.

 

[daveomak]

No, that foil is lining the bottom of the cook chamber just to make cleanup easier. I always put that down. But I am thinking about adding water to the bottom of the cook chamber instead of using a water pan. Just thinking about it , though

BTW, a while back you may recall, I posted about using digital or analog gauges because the readings I was getting between the two, were way off. Your advise was to use the analog gauge, which I've been doing. But I think I've solved that mystery.

A while back, I put gaskets on my cook chamber door. The gasket across the top of the door, keeps the door from closing completely, it leaves a gap along the bottom of the door. I wasn't concerned about that because heat rises and in the past I've run my digital temp probe wires out the bottom of the door, creating a gap.

But look at the biscuit test, the biscuits along the bottom of the door aren't as brown. And they were more doughy than other biscuits. And the biscuit that got done the least , the one in the lower left corner, was right where I put my digital temp probe. I think you can see the clip that holds the probe in that pic.

I have no doubt that gap along the bottom of the door causes those temp differences. I'm taking the gaskets off. They're more problem than they are worth.

I smoked yardbird two days ago. I put the digital temp probe on the other side of the grate, as far away from the door as possible, and I got readings that were in line with my Tel Tru gauge.

Air leaks are your worst nightmare when trying to get even heat and smoke.... Seal up ALL the air leaks...


..

 

[Smokin Okie]

I did find however that extending the exhaust stack three feet helped as well as removing the ledge where the exhaust is welded to the left side.

I think you're saying you opened up the exhaust port ? IDK why its only 4.5" and the stack is 6".

How did you do that ?

 

[JWFokker]

Tuning plates shouldn't be made out of solid metal. Should at least be cordierite (pizza stone material) like most kamados use as a heat deflector. A hollow metal box could work too.

 

[Smokin Okie]

Another biscuit test yesterday, this time with tuning plates. Also, I removed all the gaskets from the cook chamber door. I had a huge gap along the bottom of the door because the gaskets kept it from closing.

Again, I put Southside sausage on the grate. I cooked for 45 minutes at 225* to 250*. Same as last test. Cooked with door closed and damper at 1/2 to fully open, same as last test.

I put my water pan in the smoker just like I'd do if smoking a brisket or ribs. Its a 16 X 4" loaf pan that I put on top of the baffle, or in this case, it went on top of the first tuning plate.

I used two cans of Great Value biscuits from WalMart, they were the small ones, 10 to a can , so I had 20 biscuits

Spacing of plates ............. from right to left , first one was right up against the baffle with water pan on top .... 1/2 " .... 3/4" ...... 1" ... 1 1/2 " ..... 2" .... I used 6 plates.

My end-to-end temps ran hotter on the stack end by mostly about 20*

Somewhat surprised to see the hottest area of the grate to be the upper left corner. Not surprised that the coolest part was the lower left corner, it was the same in my first biscuit test. And the row along the bottom of the door was the least done, same as first test.

None of these were doughy. We ate them with sausage, honey, and butter for dinner.

Conclusion, maybe I need to use fewer plates. And maybe I need larger gaps on the FB end. Right now, I'm not sure I'll continue to use the tuning plates as they're a PITA to clean .

 

[Heart of Dixie]

Smokin Okie - I have an 20 year old Oklahoma Joe Longhorn. The steel is 3/16". My FB to exhaust end had a 70 to 80 degree difference. I experimented with a diffuser at the firebox end and 4" wide movable plates. Using an iGrill2, 4 probes, a six pack and a bag of lump charcoal I spent a couple of hours moving things around. When finished the difference was reduced to about 5 degrees. The key for my pit was mounting the diffuser plate 1" off of the FB bulkhead, butting the first movable plate under the deflector and the second plate about 1/4" from the first. The experiment showed that my original set-up with the deflector/diffuser butted hard against the firebox cut the air flow down too much. I also had to put one of the movable plates on top of the deflector to reduce the temp a bit more. I place the water pan just above the deflector. I am not saying this will work for your pit but keep experimenting and you will find the sweet spot. The attached picture with the grates removed is what works best for me. I cook mainly brisket, pork butts, ribs and a little poultry and only use oak splits.

 

[Smokin Okie]

Well, my first order of business ........is to seal up the air leaks along the bottom of the door. Look at my last pic of my biscuit test above. Very definite diff with the biscuits near the door and the lower left corner is really bad.

So when I get that straightened out, I'll go to work with the tuning plates. I just gotta take it one change at a time.

I do think I need to leave a larger gap between my baffle and the first tuning plate. I saw a post in another forum from a few years ago, where an Horizon owner had been told by Horizon, to leave 3" between the baffle and their convection plate.

 

[Heart of Dixie]

That sounds like a good plan. My pit did not leak much at all, only when coming up the temp, however I did put a thin gasket around the cook chamber before adding the tuning plate. For what its worth, my OKJ likes the firebox door open at least a few inches but I usually keep it wide open unless it is a real windy day.

 

[Smokin Okie]

BOOM BADA BOOM !!

Ran a biscuit test this evening. The clamps did the job. No more leaks along the bottom of the door.

I got one small spot on top of the stack side of the door , no biggie. Its not doing any harm.

The pics of the biscuit test don't tell the story. Last time I did a test, the biscuits near the door were doughy. They were all done this evening , crispy.

Tonights results

 

[Smokin Okie]

Bottom comparison .

Before clamp

Tonight

 

[Smokin Okie]

Ran another test this morning. Took out one tuning plate that was under my water pan, marked in crisscross red in the pic.

This left a 2" gap between my water pan and the first tuning plate.

It moved the heat to the FB end . The 2" gap is too much.

This was my set up yesterday

Showing the plate I removed

Today's set up