Cannot keep temp from rising

[PenultimateGriller]

Hi - no matter what I do I cannot keep the temp from rising and rising throughout the cook on my 32” BB
 

ive lit charcoal a bunch of different ways, with and without chimneys. now I’ve settled with lighting one golf ball spot at the edge of the basket with looflighter as I thought it would help the coals burn slower by going from one side to the other rather than out. 
 

My top vent is 1/10th turn after friction stops. My bottom vent is the tiniest sliver of the left hand vent (first small notch).  
 

I’ve let the cooker come up to 225 Both fast and slow, by opening the dampers and then closing down when I approach 180, and also keeping the dampers choked down the whole time. 
 

No matter what, the grill just keeps climbing slowly. I’m sitting about 2h into a cook now and the grill temp is 312. I cannot keep it at 225-275 no matter what I do. It usually rises to 350. 
 

i don’t know if I can close the top vent any more without stopping airflow. 
 

how do I fix this and get consistent lower temps?

Edited April 25, 2020 by PenultimateGriller

[DennisLinkletter]

I tried to call but got your voicemail..

Always remember that charcoal always burns at the maximum volume for the allowed airflow.

When you first light a KK, especially with your 32 there is a lot of material that sucks up BTUs/heat and gives you a false reading.  When the needle does not move, common sense kicks in and you open your vents  little more to get it moving, BUT your grills hot-face/body is not yet heat soaked and is still absorbing BTUs.   With some adjusting, you finally get it nailed at 235º but you did this by lighting enough charcoal for 350º.  Now when the grill's walls get heat soaked and stop absorbing heat and actually start giving off heat your grill screams past the 235º target and climbs to the 350º because that's the volume of charcoal that is now burning from the volume of air given.  Now with your grill heat soaked to 350º even cutting off all the air and killing the burn won't quickly bring it back to your much lower target temp. Also all that charcoal is lit and just opening the lid gives if more oxygen to get going again.. You are sorta up sheeit creek without the proverbial paddle.  We've all done this. few times.. my quick cheat if you can catch it quickly enough is to use a squirt bottle carefully and put out one chunk of lump at a time..

BTW unless you want the entire basket burning to grill.. you never need a fire starter volume of charcoal to start.  I generally light an orange volume and then just crack the damper top to preheat.  Always give yourself extra time until you learn exactly the settings for the desired temp. Once you learn the top damper setting.. Lite your charcoal, dial it in, walk way and just trust it.

 

[mguerra]

First, only light a very small amount of charcoal to start with. One golf ball sized bit ,as you describe, should work. Next, check for an air leak. If you have a Guru or a Stoker and your 32" has a port for same, fire up the fan and check for smoke leaks. Close the bottom vent and be sure it is pushed all the way home. Crack the top vent enough to let a little smoke out. Now that the fan is running and the KK is pressurized there should only be smoke coming out the top vent. Check the lid/body junction all the way around, and any other doors, ports or fenestrations that a 32" may have. If you don't have a Guru or Stoker you might finagle a blow dryer to blow in the port, assuming you have a port. Any smoke leaks should be evident; if you find one contact Dennis for a solution. I have had air leaks cause the temp to creep ever upward to 350º exactly as you describe. And you wind up burning all your fuel as well. If you find a leak and fix it, problem solved.

Edited April 25, 2020 by mguerra

[tony b]

Hi Doc! 

Where you been lately?? Hope all is well with you and the family! 

[Syzygies]

Burning Love (Elvis Presley)

[mguerra]

Hey Tony. I’m not too creative with my KK, just smoking briskets and pork butts over and over. So I don’t always have something unique to post. Maybe I’ll frequent the forum a little more. 

[PenultimateGriller]

14 hours ago, DennisLinkletter said:

I tried to call but got your voicemail..

once you learn the top damper setting.. Lite your charcoal, dial it in, walk way and just trust it.

 

Thanks - I did try calling you back. 
so I open the top damper to my grills’ ‘250f setting’ and don’t open the bottom vent at all?

[mguerra]

The concept is that the bottom vent is not as critical as the top vent. The top vent is the true rate limiting step to the combustion reaction. If you close the top vent and leave the bottom vent wide open, the fire might smolder a little. Very little air will flow both in and out the open bottom vent. But if you open the bottom vent full wide open and just barely crack the top vent, the fire temp won't run away. The air FLOW is the thing. And it flows in the bottom and out the top. Think of the top vent as a faucet, and the water flowing out as air. The more you open the faucet, the more water(air) flows out. And the air flow is actually the oxygen flow, that supports combustion.

[Tyrus]

I tap all the doors and check the the plugs each and every time to make sure they are all tucked in, flat against the housing and always double clik the latch. When I first received my KK the front door would always slide out just a bit upon closing the lid. I had to tweak the door a little so that I would have a little friction along those rods within the tubes to stop this. This worked fine and the door remained tight however, posting a method not quite understood by others can come ill received.  I also found the back door or gas unit door sliding out on occasion but a little push always helps it out. This area is subject to ash falling onto it and generally this aids in keeping a tight fit within the sliding mechanism since I've had it. Dirt is good. Yes, the top vent is the controller, when doing a low and slow a movement of 1/2 inch either way can offset temps 10 degrees. It takes a while to prepare the fire, generally an hour or 45 mins before placing the meat on before heat soaked, take it slow, check the boxes and it'll soon come. Accept the fact that when placing on the grates or meat your temps will always drop 50-75 degrees. Unlike other kamado's the balance here is the refractory, the patience to ease it into that zone temp you want without over shooting. The KK does all the work, you simply turn the dial.