Suggestions for minion method for a long burn on a mini-WSM using lump charcoal?

[Enkidu]

So I built my mini-WSM about a week and a half ago, but ran into a little problem on my test burn: when using briquettes, after about 7 hours there was so much ash accumulation that it filled the entire charcoal chamber all the way up to the charcoal grate (and buried the can that I had protecting the ash vent). It was suggested by several of the brethren that I use lump instead of briquettes due to less ash production, so I went out and purchased some. However, I've never used lump before.

So for those of you who use lump and have done long cooks on a mini-WSM, how much unlit lump do you use? I am planning on using my briquettes to start things off. How many lit briquettes do you use on top of the unlit lump?

I am planning on starting to cook a whole packer either tomorrow or the next day and want to do an overnight cook and would love to have it be a set & forget cook (at least until the morning when I can check to see how things are coming along). I'd like to have an idea of where to start re: ratio of unlit to lit. What I was planning to do was start with a whole chimney's worth of lump and then add about 10-12 lit briquettes. Does this sound right?

Thanks for your help.

 

[FashionBiff]

I use kingsford blue on a silver smokey joe. I do not use the can method, I just tap the kettle every half hour or so. I also keep a piece of metal resembling a cloths hanger around to do a little prodding through the vent. Keeps the ash build up inside the kettle to a minimum and the hanger moves any small coals that have fallen through the grate. I really need to add some expanded lath to the coal grate.

 

[Enkidu]

Yeah, I was using Trader Joe's briquettes on my test burn. I have used them successfully in the past when Q'ing on my 22" OTG and only had a problem with ash accumulation when I shut the bottom vent down too far so that it was open only a sliver and I didn't pay attention and clear the ash.

However, one of the reasons I built the mini-WSM (other than the fact it is cool to do and opens up some space on my OTG) was to make it a set and forget cooker. The prospect of getting up throughout the night to clear the ash doesn't appeal to me. I think the mini-WSM is capable of probably 10 or more hours at 250 or so. My test burn ran hot (around 325 degrees) and I still had unburnt coals at the 7 hour mark when the ash issue caused the temp to plummet rapidly.

However, this is what I am seeking to avoid by using lump:

 

[mbshop]

for sure you will need a basket or ring and pack the lump in. that should do it.

 

[likeadeere]

Get rid of your briquettes and stick with lump alone. I'm not sure why you would need a briquette to start lump. The lack of ash buildup from lump is astounding once you have gone from briquettes. And as far as how much to use, it's something you just have to figure out. It's all relative, if you are using a packer, it seems like a small smoker for such a big piece of meat. You'll probably have to reload a few times anyways.