The bolded part is the important part.
[QUOTE=Southern Home Boy;1512245]It was an experiment. I met a guy at a comp. that had a double drum like this but had insulated it with rock wool. He said that he used only 4 or 5 lbs of lump for a 12 hour burn and that the insulation really helped to steady temps.
That particular comp we were turning in Brisket with Tornado sirens going off. He took home at least two calls out of that one (and a GC later in the year).
Since I had been fighting to get my ProQ temps up over 200 the entire night, I had pretty much had it with wind and rain temperature loss.
I built my first drum KISS method and it worked great, but I just couldn't shake that "I need one 'dem insulated drum thingies..." feeling. So when I was able to pick up a couple of free drums - one of which was an 85 gal. one - I couldn't resist.
I does hold temps better in inclement weather and I did a few other mods too that makes it my favorite cooker in my stable.[/QUOTE]