Time to make an iron (blade) for the shoulder plane. The easiest/best way would be to buy one, for example from an old wooden plane. Nah, too easy. Or, take a chunk of tool steel the right length and cut out the stem. Still too easy for this cheap skate. What I do is cut the stem from [cheap] mild steel (usually cold rolled) and the cutting part of the iron from O-1 steel and weld them together. This saves me about $2 (6”) in O-1 and wastes about an hour. Here, a chunk of left over 5/8” x 1/8” O-1 (left) sits next to the machined stem (1/4” x 1/8” x 6”). They will be clamped to the copper plate, which will act as a heat sink and prevent warping during welding. The other two items are the TIG torch and ground clamp. Notice the chamfer at the end of the stem, this is to ensure good weld penetration (no chamfer on the iron). This will be a multi-pass weld, the root pass will be a fusion weld (no filler). The welds will be on the “cold” side to prevent under cutting the iron shoulder. I won’t be welding the sides (redundant if the penetration is good and strength is not an issue here).
Here is what the weld looks like. I use stainless steel as a filler. No reason, I have it and I like the contrast it makes with the base metal (it has a slightly different color). On the right, a quick grind and lap.
Below, the iron has been machined down to just over 1/2” wide. The final shaping and heat treatment will happen during the finishing of the plane so the iron can be fretted to the sides of the plane.