Going with the Diffuser Plate

[DDave]

After going back and forth a few times and doing some test and theorizing, I've decided that for my UDS anyway a diffuser plate is the way to go. It gives me more control, really evens out the center to edge temps (which never really bothered me thogh) and keeps some of the stronger vaporized fat taste off of the meat, which my wife does not really care for anyway.

So . . . went to Home Depot Friday and picked up one of these . . .



It's a charcoal grate from a 22.5" Weber Kettle.



It's about 17" in diameter which should give me about 2.5" around the sides.

Double wrapped it in foil which will make it easy to experiment with hole placement should I decide to poke some holes in it.



It will set on the middle rack of the drum rather than on the charcoal basket as I did in an earlier test.



Smoking a rack of spares today and so far, the plate really seems to be working well. Center to edge temps are within a couple of degrees of each other and it is pretty responsive to valve adjustments. I expect it to use a little more fuel but I'm not too worried about that.

More updates later.

Dave

[doctor phreak]

dave let us know i have been thinking about a diffuser plate myself my drum inside seems to run hot because some of my meat seems to dry out...very interested to see if this works for you

[flyin' illini]

Thanks for posting. Thinking I may go this way. Did 3 racks of spares on Friday and had to rotate them some but they turned out fine. I want to get a dome lid added too.

[Walking Dude]

yeah, a purest would say, bull on the disfuser plate, but I agree with you Dave.

I want to make a diffuser, tho I would want summin that would be just a one step diffuser. JDT had a buddy make a tuning plate/diffuser for his offset. and the dude used lasers to cut his perfect holes.

I will see if I can get him to make me one, but thinner than 1/4, as that would seem to be abit to heavy........

[Zeeker]

Looking good DDave. Hope it works out great for ya...

[DDave]

yeah, a purest would say, bull on the disfuser plate, but I agree with you Dave.

I want to make a diffuser, tho I would want summin that would be just a one step diffuser. JDT had a buddy make a tuning plate/diffuser for his offset. and the dude used lasers to cut his perfect holes.

I will see if I can get him to make me one, but thinner than 1/4, as that would seem to be abit to heavy........

Yeah, I think the tricky part would be to figure out how much space you want around the outside. From what I've seen today, I'd have to say that the 17" diameter worked perfectly for my drum since center to edge temps as measured by the two different probes on the ET-73 were most often within 2° of each other and at the most 6°.

But the BEST part for me was the temp control. I never even touched the valves when opening the lid to spritz. When it was time to foil, I just took the rack out and put the lid on while I was foiling, but again never messed with the valves. And the real test was during the final hour, I usually put on some sauce/glaze every 15 minutes. By the end of that hour, the temps are usually 280°+. Today, it was ridiculously easy to keep the temps in the 240s since the plate was there to interrupt the airflow somewhat.

I shut down the vents afterwards and haven't taken a look at fuel consumption yet but I don't think it will be enough to make me go back. The meat did taste better too but I also let the drum warm up alot longer until ALL the light smoke cleared so I don't know if this had much to do with the plate or not, but I'm sure the plate contributed to a cleaner burn since more fuel wasn't trying to light every time I took the lid off.

dave let us know i have been thinking about a diffuser plate myself my drum inside seems to run hot because some of my meat seems to dry out...very interested to see if this works for you

I'm pretty happy with the diffuser. One thought I would have on yours though is double check your center grate temp. If you are using a dial thermo, you need to compare it with what a digital probe at the center says when your at your preferred smoking temp. For instance, my Teltru on the side reads 200° to 220° when the center is 220° to 240°. There was even a bigger difference before using the plate.

Dave

[Walking Dude]

problem with a 17 inch dia. diffuser is I would need longer bolts. Which mite interfere with my basket, taking out, and putting in.........I will have to check that out.........

I know Tips drum, without a diffuser, his temps is 30 degrees diff. from edge to center, with the center being hottest. Of course.

[Smokin' Dick]

I am a firm believer in using a diffuser in a drum for all the reason you spell out Dave. The only down side is that more fuel gets burned when using a diffuser. So be it. The drums are so frugal with fuel it is a non-issue. IMHO.

My plate is made from the cover to a 30 gallon drum. It measures 19" in diameter and has artfully located and precision drilled holes of various sizes. Much thought and scientific examination went into the hole placement and determination of diameters. Translate that into a couple of beers later, the thing had holes. It does the job intended and I'm happy with it. It rests right on top of the charcoal basket so no extra hardware needed.

Here is a pic of said diffuser plate.



Just did a 14# brisket overnight and I slept for a good 8 hours while ReDrum was smoking away. Fat cap down and just the right amount smoke and bark. No the too smoky taste I would get without the plate. Good Luck with yours.

It's a good thing I previewed this post before submitting it or you would be listening to The Platypus Song instead of seeing my fine craftmanship!

For those of you who would RATHER hear the song, here's a link:

http://www.youtube.com/watch?v=0gM5TjSOQ48

[Fishawn]

Neat thread..... You guys with your UDS's and the mods & options are doing great work

[DDave]

problem with a 17 inch dia. diffuser is I would need longer bolts. Which mite interfere with my basket, taking out, and putting in.........I will have to check that out.........

What you could do is have someone make a ring out of 1/4" rod that will set on your existing bolts. Then cut a plate to the size of a circle that will work for your drum. Then weld "spokes' from the plate to the ring.

Something like this.



Please excuse the crappy drawing. It's the best I could do quickly in MS Paint.

The outer ring would rest on normal length bolts but it would be open from the inner plate to the ring.

It measures 19" in diameter and has artfully located and precision drilled holes of various sizes. Much thought and scientific examination went into the hole placement and determination of diameters.

I like it.

Hmm . . . I may have to experiment with a few holes to moderate the amount of smoky flavor.

Dave

[Richtee]

Well, what the hell... I TOLD YA ALL SO ;{)

[Walking Dude]

Hmm . . . I may have to experiment with a few holes to moderate the amount of smoky flavor.

Dave

To me, I would think it would be like a tuning plate in a offset. small holes where the heat is the hottest, and progressively, the holes get larger the closer they get to the colder part of the offset. Same way here. The center will be the hottest, so little holes, and bigger as they go to the outter edge where its cooler.

[Richtee]

Hmm . . . I may have to experiment with a few holes to moderate the amount of smoky flavor.

I use the exact same deal in my WSM. No holes...but if you determine you need them, poke them from the "back" preventing "pools" that the fat will collect in and drain into the coals.

[doctor phreak]

I am a firm believer in using a diffuser in a drum for all the reason you spell out Dave. The only down side is that more fuel gets burned when using a diffuser. So be it. The drums are so frugal with fuel it is a non-issue. IMHO.

My plate is made from the cover to a 30 gallon drum. It measures 19" in diameter and has artfully located and precision drilled holes of various sizes. Much thought and scientific examination went into the hole placement and determination of diameters. Translate that into a couple of beers later, the thing had holes. It does the job intended and I'm happy with it. It rests right on top of the charcoal basket so no extra hardware needed.

Here is a pic of said diffuser plate.



Just did a 14# brisket overnight and I slept for a good 8 hours while ReDrum was smoking away. Fat cap down and just the right amount smoke and bark. No the too smoky taste I would get without the plate. Good Luck with yours.

It's a good thing I previewed this post before submitting it or you would be listening to The Platypus Song instead of seeing my fine craftmanship!

For those of you who would RATHER hear the song, here's a link:

http://www.youtube.com/watch?v=0gM5TjSOQ48

you gave me a idea i have a 16" old pizza pan that we really dont use anymore wondering if i could use that just make some bigger holes in it...any suggestions

[Smokin' Dick]

you gave me a idea i have a 16" old pizza pan that we really dont use anymore wondering if i could use that just make some bigger holes in it...any suggestions

Since this whole thing is experimental, use the pizza pan as is on a test cook.
Then use a Uni Bit to drill some holes if/when you deem them necessary. Smaller near the center and larger towards to outer edge. That was the original premise of the one I did, but these things seem to have minds of their own!
More holes have shown up in the plate since that picture was taken, so watch for the evolution on yours!