Spent the weekend building a konro grill from junk steel and a vermiculite panel

I had a similar project a few years back when I needed a compact cooking solution for the woods. I used salvaged steel from an old appliance rather than just angle iron. The biggest thing I learned was how important the base clearance is for consistent heat distribution, expecially since you are sealing the top so well. Even if your frame is solid, if the coals sit right against the metal base, you just get hot spots instead of even radiant heat across the entire cooking surface. I ended up building mine on a slightly elevated cinder block base, wich gave about three inches of space underneath. This allowed for a small, passive chimney effect drawing oxygen through the bottom, which seemed to really boost the temperture profile inside the drum. I experimented with a small, perforated tray on the very bottom, rather than just a flat rebar grid, which seemed to improve the initial ember catch significantly. It was a bit of a headache getting the fit right when I was cutting the sheet metal, but once it was stable and the gaps around the edges were sealed with some high temperature caulk, the thermal performance was what I was hoping for. It took some trial and error to get the right balance of intake and venting, but the results were definately worth the effort for a camp setup.

I had a go at building something similar last winter using some old galvanized sheeting instead of the vermiculite boards. The initial idea was just to block the wind and hold the heat, but using those thin panels meant I had to cut custom spacers because of the thickness of the metal itself. It ended up holding a bit of heat longer than I expected, which was interesting. I figured since the original setup was using small holes for air flow, I should reinforce the bottom. I used a couple of pieces of old rebar, but instead of just sitting them flat, I actually welded the base of the frame to these bars. This helped keep the bottom from warping when the internal temperatures got high, which is something that just happens when you're dealing with consistent radiant heat. My main concern with the original design was the rigidity of the frame. If you are just tack welding thin steel, it seems like it could twist under the weight of charcoal and heavy food. I switched my method to using longer corner braces, bolted down first, then tack-welded, just to get that frame square and stable before I started filling it in.

Nice one, the vermiculite boards are a game changer for this sort of build. I did a similar thing for my brother's place last spring, though I found the board likes to crumble along the cut line if you rush it. Scoring it a few times with a utility knife first and snapping it over a straight edge gave me way cleaner edges than a saw did. One thing I'd keep an eye on is ash buildup under your rebar, mine choked up after three or four cooks until I started raking the clinker out between sessions. Did you leave any gap at all around the board or is it a snug press fit?