Fire brick/s in place of a heat deflector or tuning plate?

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Master of the Pit
Original poster
Jan 18, 2020
So while I'm waiting for my second box of 6 fire bricks to be delivered, I can't help but wonder how well they would work to deflect heat at the transition from firebox to cook chamber?
Anyway, I'm going to fiddle around with the ideak and see if I can place one or more in there and see what happens.
I'm going to try using some flat fire bricks (7x12", 1/2" thick) in my OK Joe Longhorn smoker. Mine is a reverse flow, and the side closer to the firebox is 50 degrees hotter (heat rising through the floor.) I'm thinking about laying the bricks over the floor, close to the firebox.

I made sure to get the "soft" fire bricks, as they reflect heat back towards the source. "Hard" firebricks are heavier and allow more heat to seep through.
So while I'm waiting for my second box of 6 fire bricks to be delivered, I can't help but wonder how well they would work to deflect heat at the transition from firebox to cook chamber?
Anyway, I'm going to fiddle around with the ideak and see if I can place one or more in there and see what happens.

Let’s see some pics of a configuration you come up with. Always looking a for a tweak on mine.
Will do but early experiments (no fire testing yet) seem to show that I can partially block the opening between the firebox and cook chamber on the firebox side, leaving two or three inches open at the top with a little leakage on both sides and can do more or less the same by setting two across the ledge on the cook chamber side.
I bought a brick cutting blade for my sawzall and both ideas would work better, or fit better really, with some brick size alterations.
Tomorrow I have to cook two dino racks, I forgot to put them in the freezer and their sell by date was Oct 21.
They smell fine so I'm not worried but dang this is interrupting my fire brick diddling.
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I'm going back to square one. My dino rib cook was a swirling mess.
First mistake was to start too big a fire and I never really got control after that, chasing temps up and down over and over.
Not to worry, the ribs came out pretty good, I just had to paddle upstream the get them there.
All I really know is this seems (so far) to be a pick a spot to place the meat and cook in it, and only in that spot because on either side of the sweet spot it's too hot or too cold.
To make matters worse, as the fire matures and wanes the sweet spot changes so the meat needs to be shuffled around to stay in the desired temp range.
I even broke down the set up mid cook, removing the meat and all 8 probes, to change the position of the deflector, which by the way did nothing meaningful, but it did give me a chance to try out my new long gloves.
Anyway I've decided to flip the charcoal grate and drill holes in it.
Perhaps someday I'll get to the fire bricks but it would seem to me that adding them will increase the heat getting into the cook chamber, which might be a good idea on it's own but won't help getting more even cook chamber temps.
And on that subject, I'm thinking adding the bricks will allow a smaller fire to deliver the same amount of heat to the cook chamber that a larger fire would deliver and thereby save valuable post oak mini-splits.
Just a couple of suggestions. First of all 50 degrees at the fire side isn’t that bad and it can be use to your advantage when you cook.

However, adding a row of fire bricks will help stabilize the temps….. but you want hard bricks not soft. Get 3-4 splits (1/2 thickness), you can usually get this at any fireplace or brick place store for a couple buck each. The soft are insulating bricks and most don’t play nice with food….the hard will absorb the heat the radiate it back into the chamber at a slower rate.

Next if your cooking chamber is bouncing between 215 to 285 ish simply don’t mess with it this is completely normal and you are doing well. Smaller reverse flows fluctuate a higher range and it’s perfectly normal.

They this in you me next cook. Get a full chimney fully lite up and pour that in the fire box. Then add 1 to 2 2-3 inch splits at a time (when it drops to 220-215). As they fire up the temp will spike a bit but then should drop back down (don’t mess with the air to try to slow them from lighting). As the cook goes if it spikes too much just add 1 split more often. On a long cook after an hour in start adding 2 to 3 charcoal pieces with the splits to keep the coal base nice and hot. Having a nice coal base will stabilize thing a lot for you.

Now for the 50 degree delta. The hard bricks will help this but this area becomes your roasting area to finish off the bark, set a glaze or help a item that is moving slower than others so it’s not a bad thing if used in the right way. Oh when not using it as a roasting area you can also set a water pan in the great on that side which will also help even things out and humidity which is a good thing.

Good luck and realize it takes a few cooks to get the hang of things…
This was my second cook, first was two brisket points and two dino ribs.
I started with small pile of lit charcoal and added small splits and kept the fire small the entire time.
The temps were easier to control and with some shuffling of meat near the end I was able to get it all finished at the same time.
I had to add wood every 15 to 30 minutes for 12 hours and on this second cook I wanted to see If I could wrangle it with larger sticks which would last longer between feedings.
I need to do some wood splitting and cutting so I can have enough tiny sticks to go that route but I am going to run a test next week with the charcoal tub inverted just for grins and will report back on that adventure.
I have a brisket point soaking in pastrami brine now and it has to get cooked in no more than 10 days of the start of the brine, so next weekend or shortly thereafter I'll gear up and attack again.
More coals will help increase the time between splits, a 25-40 min between is very normal and what I have found on my Copper pot. Just note that your coal base will provide uniform heat and the splits add the flavor tone.

If you don’t have enough coals for the base heat then you will be reliant on a consistent fire and fire management. It seems backwards for a stick burner but it will make you cooks way more consistent and enjoyable
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