Originally Posted by angrybird
Had my first cook in my UDS that was finished about a week ago... I had some temp problems and was hoping someone could enlighten me.
I lit 15 coals in my chimney. I've got 3 3/4" intake holes and 8 1/2" exhaust holes around the circumference of the lid. I put pipe nipples on two of the intakes when temps got to around 210. The third 3/4 is a ball valve and was left open. No exhaust holes were covered.
The temp climbed and ranged mostly between 280 to 300 it probably would of climbed higher if I didn't take off the lid occasionally to cool it off. I couldn't seem to bring it down with the intake adjustments. I also didn't want to completely close off my intake ball valve on the third hole. But, I did close it about half way. Still was hot.
There doesn't seem to be any leakage in the drum. When I close all the holes, the fire goes out pretty quickly. Any ideas on what I can do to keep those temps down? Do the exhaust holes need to be slightly bigger?
Keep the lid on. Taking the lid off will let heat escape & temp will drop around your cooking grate in the short term. It also allows a lot of oxygen into the drum that will make your fire burn hotter. That's why your temp spikes when you put the lid back on. If temps spike, you can close off all the intakes to choke the fire down. Drums hold heat very well so it takes longer to bring temps down than up. Close off all intakes & wait for temps to start to fall, then open the valve up about halfway. Be patient & wait for the temps to stabilize before make any other adjustments. It can take 10-15 mins or more before it settles in. From that point on make very small adjustments to the intakes & give them time to work.
My drum has 3 nipples, one with a ball valve. I cook most of the time around 275 & have two nipples capped & the ball valve only 1/2 to 3/4 open. I use around 10-12 briquettes to start my fire. I cap off one nipple at 220-225. The second at 250-255. At 265-270, I close the valve halfway. Within 10 mins, it usually has settled in between 275-280. If not, I make a small adjustment to the valve to dial in the temp I want.