New to Weber Kettle (and grilling in general), but I can't seem to keep the heat going

[Dosstx]

I'm new to the Weber Kettle and just purchased an 18" where I've done a total of 3 cooks so far. I'm still learning, but it often feels like I'm not using enough charcoal (I am using basic kingsford) because it doesn't stay hot that long (maybe about 30mins of stable heat?) I do use a chimney starter and wait until the briquettes are completely gray before pouring into the Kettle. The manual says to use about 40 briquettes for the 18" grill but I feel like I should add more than that. Is this normal or am I doing something wrong? I did try out chicken thighs (bone in) yesterday and it looks like the heat started to decrease about 30mins into the cook. Do I need to add more charcoal about halfway through? This might sound dumb, but the recipes and stuff I've read here and elsewhere never mention to add more fuel in the process : )

Thanks for any advice!

[LA Pork Butt]

What are you trying to cook? Most grilling can be completed in 30 minutes. Is it possible you are over cooking your foods? Are you using a two zone fire?

[Mr. Bones]

Howdy from Kansas Territory, Welcome to Th Pit!
Lookin forward to learnin along with, an from ya!

40 lit briqs is probly okay to direct cook some burgers, brats, etc., an be done with it.

Help us answer yer question by providin some more info, please...

What are ya cookin / wantin to cook?

Direct or indirect heat?

Have ya been cookin lid on, or off?

How have ya been havin yer vents set?

There's more variables, but this will help us git started dialin yer kettle cooks in.

Glad to have ya here! Never be afraid to ask questions here, reckon I've done asked up alla th stupid ones, afore ya got here...

[GrillinNC]

Those of us with the PBC (Pit Barrel Cooker) start off with 40 briquets, so unless you’re going full blast furnace, I would think you could get more than 30 minutes with the lid on and vents set properly. That said, you could have a bad bag of coal.

Here in NC, I have seen bags of charcoal sitting put in the weather at some of the big box stores. Maybe pick up a new bag from a local Ace/True Value...try that and see how it goes.

[Rod]

Like Mr. Bones Bones said, if you can give us some more detail that will help lead you to the right answers.

I know one thing for me, I never let the coals completely ash over in the chimney. I'm ready to dump them when the smoke is gone or maybe just a few wisps of smoke. The top layer of coals are just barely starting to ash over on the edges. If you wait until the top coals are completely ashed over you've lost a very large amount of cooking energy and life expectancy from them. I believe Huskee taught me that.

[Texas Larry]

+1 on this.

[jfmorris]

^^^ this ^^^

[Huskee]

Aww, you makka me cry

[Loren]

Do you have a thermometer that you can leave in the grill to measure temp?

I would imagine 40 briquettes would get you more then thirty minutes of heat.

Moar deets needed

[mountainsmoker]

Welcome, where you be from. How did you have your vents set. 40 briquets should be fine. You want to cook chicken thighs at high heat to crisp the skin and cook to 175 degrees. I have cooked on a Weber 22 kettle since the late 1970's so my question to you is why the 18", unless it was for room or cost.. I will agree with GrillinNC if you did not buy your charcoal from an inside area that might be your problem. Although I keep mine under a covered porch and never have a problem, but I buy it from an inside area

Rod makes a good point I only let them ash over about 1/2