Trouble keeping temps up on my UDS

Kaptain Kadian said:

If you got the temp up by cracking the lid, it is a good indicator you don't have enough exhaust. Need more exhaust that intake. It is easier to choke off exhaust than not have enough.

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That's the thing. The temp was the same with the lid cracked or closed. The temp dropped when I had the lid completely off but that's because it let all the cold air in.

I guess I'll just wait till my homemade guru is done later this week. A fan blowing air directly on the coals should make short work of any problems with temps being too low. I'd really like to get this figured out though. I am going to widen up my exhaust vents another 1/8" to get them up to 1/2". I really don't see how that is the problem if the temperature stays low even when the lid is cracked open. Based on what I've read, and my test run, these things should get really hot with all vents open.

The pic in #15 was before I washed it out. I think that may have been some ash on the bottom left over from the burn out. But the intakes are wide open. I'm doing another small cook today. I'll open up the exhausts to 3/4" before I start. That is roughly equal to a 2" bung hole. I'll also play around with how much I start in the chimney. My fuel is getting pretty ashed so I'll pick up some briquettes to top it off and try something different. I'll try 15 briquettes and see if that helps get the temps up at start. About how long does it take for the UDS to get up to temp?

Maybe I'm just impatient. I usually stick my meat on soon after the coal basket goes in. I figure it can cook at a lower temp until it gets up to temp. Just get things started a little sooner. I'll wait till it's fully up to temp before putting meat on this time and see if that makes a difference.

I use a small pile of lump. Maybe 8" diameter and 4" tall. I wait maybe 15 minutes. In that time they are probably 25-50% ashed over. I'm probably jumping the gun aren't I.

Good info. Thanks guys. I'll report back after my cook tonight. I think my problems are 2 fold. Not enough exhaust and not giving the coals enough time.

Ok that did the trick. I widened the exhaust vents to just shy of 3/4" and I let the coals get good and hot before I added them to the basket. I also left the lid off of the UDS for a good 15-20 minutes with all intake vents wide open. When I put the lid on, the temp rose to 325 over the course of 15 minutes. I then closed all the intake vents for 10 minutes or so to get the temp back down. When it was about 250 I put the meat on and opened 1 vent. It settled into 225 and stayed there for the whole cook. It is truly awesome to have some true BBQ geniuses here to help out a noob like me.

The size of my exhaust holes. There are 8 of them evenly spaced in a circle about halfway from the center of the lid to the outside edge.


What my charcoal basket looks like after 3 cooks. It was full at the beginning.


My ghetto home made charcoal chimney. This is how much lump I started and what it looked like right before I put it in my basket. That is 1/2" hardware cloth for scale.


The arrangement of lit charcoal in the UDS right after I put it in. The hardware cloth was bending around the 3" bolt legs so I decided to just set the whole thing on a few half bricks. I really need to make a new basket


Coming up to temp soon after I put the lid on. I can't tell, is this "sweet blue" or "ugly yellow" smoke?


Peak temp before I brought her back down to 225. I need to get a digital thermometer and set it in the middle of the grate to see what the temp difference is between center and wall.