Just take a piece of expanded metal and make a cylinder out of it without a bottom and set in down on top of the fire grate. Put your lump into it and fire it up.
Your idea was a good one. I have not tested it yet, but I made it.
I was at the Lowes near me to get some painting supplies and I thought I'd pick up the expanded metal and stainless cable ties if they had the items. They did. The expanded metal was $10 for a 2'x1' piece of medium gauge. The ties were $3.
I have a pair of heavy duty shears so I measured the 6" mark and cut it to two 2'X6" lengths. I cable tied with some overlap and used a 5 gal. bucket as a "form" while I wrapped it and cable tied the other side. Expanded metal is not the easiest stuff to work with:mmph: and gloves are a necessity unless you want your hands looking like pizza or hamburger.
Also, I tried to round the razor sharp points where I had cut, including the cable ties with my bench grinder and my drill with a grinding wheel on it.
I'll try it probably Sunday if it doesn't rain. I think it will distribute the heat a bit more broadly and evenly then the duct reducer which I believe had somewhat of a chimney effect. Although a decent diffuser would probably correct that. Bottom line, for sure it will serve my original intended purpose to allow for portion control of the lump and to contain it better.
Here are some pics. also, since it was so warm and sunny yesterday, I sanded and stained the wooden side shelves with some leftover acrylic deck stain. The original finish was kind of humble and was not holding up well. Density524, I believe mine to be the same color as yours and certainly not the jet black of the Lowes edition. I have the stainless damper. With an earlier mod (rtf high temp. sealant)and some gunk buildup, it works fine although the black cast metal on the more models is definitely a design improvement.
Do you think Weber will come out with a Kamado? They essentially already manufacture the main components. Would be a great addition to their range.