The wrapped corner is a common technique used on non-patterned sheet vinyl. It will take more of a beating than a mitered outside corner, which is why it is recommended for this type of material. The wrapped corner can be heat welded or can be left seamed, as I am going to demonstrate.
Photo #1: Cutting down the cove stick. The first thing is to cut the point off of the cove stick. You will need to round the point so you can wrap the corner. You do not have to do anything to the cap metal.
Photo #2: Cutting the corner. Measure from the top of the cap metal to the bottom of the cove stick. Then measure on a scrap piece of material, and place a small mark representing the measurement taken. Lay a square down and equalize each side, keeping the point of the square on the mark. Cut the two sides.
Place two lines, one at the top of the corner and another at the bottom about 1/2” up from the point. Cut about 1/2” off the point. The two reference marks will help you position the corner at the cap metal and the cove stick.
Photo #3: Heating the corner. Spread contact adhesive on the back of the material and on the wall, and allow it to dry. After it is dry, heat the corner at the center. Pay special attention to the area around the cove stick.
Photo #4: Fitting the corner. Line up the marks with the miter on the cap metal and place the top of the corner, working from one side to the other. After one side is completed make sure both marks are aligned and continue to the other side. Roll thoroughly with a hand roller to ensure a good bond.
Photo #5: Cutting the felt to the corner. You need to cut the felt close at the corner. Remember, for the rest of the pattern work you need to just be close, but at the corner you need to be precise.
Photo #6: Scribing the corner. Scribe with dividers with your normal setting, but at the scribes at the corner, close the dividers as much as possible. Make three scribes: one on each side and at the bottom. Then transfer the reference mark at the cove stick to the felt.
Photo #7: Cutting the material. It is OK to bevel the cuts along the cap metal but at the corner keep the cuts good and square as they are going to have a seam, which will create a little stress at that point. Transfer the reference mark to aid in positioning
Photo #8: Fitting the material. Apply the adhesive. After the open time (if any), place the material into the adhesive and position it on the reference marks. Start from the corner. Heat the material and use a suction cup to lift the material and set the bottom of the corner, first. Then get the material laying flat and proceed with the corner.
Photo #9: The finished corner. At this point, clean up is all that is necessary. If you are going to heat weld, you can do it in the prescribed time for the adhesive to dry, or you can leave as is. Congratulations. You’re done.