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Smokers, Grills, Pitts & More => BDS & UDS Smokers => Topic started by: FatCharlie on August 30, 2010, 11:43:53 am

Title: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on August 30, 2010, 11:43:53 am
I've used foil on racks with water trays in attempt to minimize the direct heat that most UDS smokers experience during a smoke,
especially those with larger fires and fire basket.

Anyway, I thought I'd work on a diffuser design that would prevent the flare up from getting close to the food, provide a water tray area
and evenly distribute the heat throughout the drum.

Going to give it a try next weekend on some ribs...

(http://a.imageshack.us/img828/3333/uddiffusers.jpg)
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: Gizzy's Smokin Crew on August 30, 2010, 12:37:28 pm
Keep us posted....Looks interesting. Don't forget the pic's
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: Quiggs on August 30, 2010, 06:34:48 pm
OH yeah that looks like great idea.  Keep us informed, I have been thinking of some type of similar thing but was going ceramic, this would be easier..

Quiggs
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: KidCurry on August 30, 2010, 07:58:17 pm
I like it.  Keep us posted.
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on September 26, 2010, 05:38:19 pm
Well, I did some ribs a couple weeks ago.  Placed the original diffuser about 10" above the charcoal basket.
The drum intake regulation wasn't affected and the drum got up to temp as usual.
I placed the digital probe at the center of the drum, about 10" above the diffuser and directly below
the grate with the meat.

Early into the cook, I still had the 30 degree difference between the digital thermo and the two analogs I have on the
outside of the drum. After about 1 1/2 hours, the difference was 15 degrees.  Not really sure if the diffuser
had anything to do with it though, I think a lot of drum stabilize over time throughout a cook.

Anyway,I feel the center was still too hot so I have modified the diffuser.  One less concentric circle and
narrowed down the next rings except for the outside ring.  Plus it's now made out of 12 gauge steel.

(http://img138.imageshack.us/img138/3100/rev1post.jpg)


Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on October 18, 2010, 10:41:04 am
Well, I gave it a test this weekend. Any temp over 300 and the digital thermo in the middle of the drum was running 10 degrees hotter than my side 2" analog thermo.

I still have a +30 degree difference from the center to the side in the 200-250 degree temp range.

Revision #3 is being tested on 3) BUFORDS next Saturday;

(http://img824.imageshack.us/img824/4690/diffuserrev3.jpg)
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on November 29, 2010, 08:05:27 am
I tested Revision #3 on 3) BUFORDS this weekend. Drum #1 had 6) coiled large baby backs on the top grate, Drum #2 had regular sized baby backs on the top grate and Drum #3 had two racks (10 lbs) of wings.

First, the success story;
Drum #2 had Rev #3 diffuser placed at about the second ring on the drum. Six coiled regular sized baby backs were placed on the top rack of the cone top drum. Fire started and within 45 minutes, the drum had settled in at 225 degrees and held 225-240 throughout the entire cook with only a few tweaks for regulation.

Prior to the cook, I placed a digital probe (Maverick) about 6 inches above the diffuser to monitor the center heat. The digital center probe read 225-240 and the two outside edge analog gauges (2.5" probes) read with 1 and 10 degrees of the digital throughout the entire cook! Definitely a success!

(http://img834.imageshack.us/img834/574/diffuser3centertoanalog.jpg)

(http://img573.imageshack.us/img573/6213/diffuser3balance1.jpg)

Drum #1 had diffuser revision #3 but had the largest ribs on the top shelf. There was very little space between them when placed on the rack. Diffuser was placed about the second ring on the drum and the digital probe placed in the same spot. This cook took a little more regulation and we saw 20 degree temperature differences between the analog and digital thermos. The diffuser #3 is not a good fit for meat that is packed heavily on the grates which restricts the exhaust. And, number two, there were three of us tweaking it throughout the day and we didn't communicate our adjsutments between us. Too many cooks in the kitchen.

Drum #3, diffuser #3 had two racks packed full of chicken wings and the digital probe placed a few inches above the diffuser that was about the second ring on the drum. I saw about a 20 degree difference between the digital and the analog gauges on this cook as well. I also encountered another problem. I was unable to get the drum up to temperature. Way too much blockage by the diffuser and the two layers of chicken wings which were also tightly packed on the grates. I was able to increase the temp by openening and closing the side access door that is on the BUFORDS to get the temp up.

Overall, it looks as if the Diffuser #3 worked perfectly on Drum #2 with 6 coiled normal sized ribs. Throughout the cook, the center drum temps were within a few degrees of the side analog gauges. I'll do some more eperimenting on this design.

I would not recomend Diffuser #3 for those cooks that have tightly packed meat on one or tow greats. The diffuser, with the tightly packed meat restricts the exhaust flow through the drum causing temperature temeprature fluctuations and excessive smoking issues.
Diffuser #2 would probbaly work better since it has more vent rings cut into it.

BTW, the ribs turned out fantastic, good even bark, no charred ends, nice smoke ring, succulent! The wings turned out ok, rubbery skin, too smoky due to low exhaust ventialtion early in the cook.
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: ThunderDome on March 25, 2011, 09:09:31 am
I need one!

Are you selling?
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: shortbus_35 on June 01, 2011, 03:16:43 pm
Are you selling these diffusers??

and how did you make the thermometer pass holes - they look awesome.
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on June 06, 2011, 03:39:16 pm
I got a price of $30.00 for plasma cut diffusers.

The thermo pass holes are electrical glands you can buy at Home Depot.
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: ThunderDome on June 14, 2011, 04:23:30 pm
I got a price of $30.00 for plasma cut diffusers.

The thermo pass holes are electrical glands you can buy at Home Depot.

I just sent you an email. I can PM you on this if you prefer. Thanks
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on June 15, 2011, 04:05:23 pm
I just sent you an email. I can PM you on this if you prefer. Thanks

rx'd and responded  8)
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: shortbus_35 on September 26, 2011, 07:48:29 am
I got a price of $30.00 for plasma cut diffusers.

The thermo pass holes are electrical glands you can buy at Home Depot.

Great to meet you FatCharlie and thanks for all the discussion about the diffuser!
I need to get that basket measured so I can correct the handle to accommodate the diffuser.
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on September 26, 2011, 07:01:49 pm
Great to meet you FatCharlie and thanks for all the discussion about the diffuser!
I need to get that basket measured so I can correct the handle to accommodate the diffuser.

Hope it works out for you!

Bring that basket by if you need it modified.
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: shortbus_35 on November 17, 2011, 05:11:29 pm
Thanks for the help with my basket.  Cooked some pork loin this weekend and it worked much better than the original design.  It was much appreciated!
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: ThunderDome on November 21, 2011, 10:39:57 am
Hey SHortbus, did you get a diffuser?

I love mine
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: shortbus_35 on December 03, 2011, 12:46:49 am
I finally bought one directly from Fat Charlie.  I've cooked with it twice and love it
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on December 05, 2011, 04:11:24 pm
I finally bought one directly from Fat Charlie.  I've cooked with it twice and love it


 8)
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: FatCharlie on December 05, 2011, 04:13:09 pm
Thanks for the help with my basket.  Cooked some pork loin this weekend and it worked much better than the original design.  It was much appreciated!

Excellent, I'm glad it worked out for you!
Title: Re: *NEW- EXPERIMENTAL* UDS Diffuser
Post by: Bill Bain on May 20, 2012, 07:16:38 am
I've had my diffuser from Fat Charlie for almost a year and I can tell you the results have been outstanding.  The heat is more spread out and not so centered, the drippings sizzle on the diffuser and add to the flavor of the meat.

Highly recommended.