Technique
Cutting 45° Mitered Corners in 1×2 Rectangular Tube
Every visible corner on this welding cart is a 45° miter. Six of them close the base frame and the top frame over the welder. Here's how to cut them so the frame comes out square.
Why miter only some corners
Miters look clean, but they're slower to cut and fit than square butt joints. On this cart only the corners you can see are mitered: the four outside corners of the base (A, B and both Cs) and the outside corners of the L top frame. Every interior member butts square into the inside face of the member it meets, out of sight. The corner detail on the plans shows the joint.
Step by step
- 1
Stand the tube on edge
Set the 1×2 with its 2" face vertical. Every miter on this cart is cut across the 1" face so it closes the corner in plan, seen from above.
- 2
Cut the mitered pieces first
Start with the long mitered rails. If a miter goes wrong you can still recut it shorter into a square-cut interior piece.
- 3
Measure long point
Mark the length along the outside face, point to point. For the base frame that's 62" for A and B and 33" for each C. The short point on the inside is 2" less.
- 4
Test-fit before cutting the mate
Cut one end, hold it against a framing square with a scrap mitered piece, and check the corner closes tight. Adjust the saw before cutting the matching piece.
- 5
Tack and square the perimeter
Lay A, B and both Cs on a flat surface, tack the corners, and measure both diagonals. Adjust until they match within 1/16" before welding out.
Budget for miter waste
Each mitered end costs about 1" of stock on top of the 1/8" saw kerf, because you want to cut each miter from a fresh square end. The cutting plan already allows for that, which is why stick 1 carries three mitered pieces and still has about 5⅛" left.
Cap what stays open
Where a tube end is visible and not mitered into a mate, like the top of the cylinder upright or the L front arm at the vent gap, press in a 1×2 plastic end cap. The cart uses five.