A charcoal grill is the first welded project for most people: it looks like nothing more than a sheet, an angle grinder and a welder. It almost always works, too — the only question is how many seasons it keeps its shape. Here are the dimensions and decisions that separate a two-year grill from a ten-year one.
Dimensions start at the skewer
The reference is the skewer, not the sheet. A standard skewer has 45–50 cm of working length, so the internal width is 30–35 cm — the skewer should rest on the walls with margin rather than drop inside. Spacing between skewers is 8–10 cm, which sets the length: about 55–60 cm for six skewers, 90–100 cm for ten.
Depth from coals to skewer is 15–20 cm. Less and the meat chars outside while staying raw inside; more and the charcoal burns away for nothing. Wall height is usually 20–25 cm, of which 5–7 cm is the bed of coals. Legs run 70–80 cm to the top edge so you are not bending over the heat.
Thickness is the decision that matters
This is where most home-built grills fail. Sheet of 1.5–2 mm is cheapest and easiest to work, but after a few big fires it warps: the floor bows, the walls spread and skewers start rolling. That thickness makes sense only for a camping grill you do not mind losing.
The working compromise is 3 mm: it holds its shape for years and still lifts with one hand. Stationary grills and barbecue units are built from 4–5 mm — almost no warping and better heat retention, at noticeably more weight. Stainless looks best and needs no paint, but costs more and warps just like mild steel below 2 mm.
Air holes, not a slot
Air holes go in the lower part of the side walls — 3–5 cm above the floor, 10–12 mm in diameter, spaced 5–8 cm in a single row. A common mistake is drilling the floor instead: the coals burn through faster, the heat goes down and ash falls at your feet.
The alternative is a continuous slot along the wall, but that costs the wall its stiffness and the grill eventually cracks along exactly that line. If you need more air, add a second row of holes rather than turning them into a slot.
A folded body beats a welded one
There are two ways to build the box: weld five separate plates, or cut one flat pattern and fold it on a press brake. The folded version is stronger because it has no welds in the corners — and the corner weld is exactly where a grill splits after a few seasons. It also removes the guesswork of squaring the plates by eye.
In practice that means the hardest part — cutting the flat pattern with the air holes in one pass and folding it on the brake — is the part worth ordering, while welding the legs and assembling is easy enough at home. The flat pattern is calculated with the bend allowance for the specific thickness: at 3 mm, getting that wrong throws each corner off by several millimetres.
Paint: what works and what does not
Never paint the inside — any coating in the coal zone burns off the first time. Outside, use a heat-resistant silicone paint rated from 400 °C, in two thin coats over a degreased, cleaned surface.
Ordinary powder coating is not for the firebox — the polymer is made for domestic temperatures. It is excellent, though, on stands, side tables, lids and barbecue trolleys, that is, on everything that does not touch fire directly.
When ordering is simpler
Count honestly: 3 mm sheet is sold whole, and after the grill you are left with an offcut that will sit in the garage for years, plus cutting discs, electrodes, heat paint and a day of work. Made to order often lands at the same money, with square geometry and a folded body free of corner welds.
We build grills in our own shop — from compact folding units to stationary ones in heavy plate, including to your sketch and dimensions. Laser engraving with a name or logo turns one into a gift. See the ready-made section or send us your size.
