Things You'll Need
1-1/2-inch seam tape
A traditional welding cap is made with flame-proof natural fibers and is designed to protect your head and hair from fire, sparks and ultraviolet radiation. All welding caps follow the same pattern regardless of how large or small they are. If you plan to do some welding and want to save a little money, you can make your own welding cap out of lightweight denim.
Draw a vertical line on a piece of paper that is 7 inches long. Then draw a horizontal line that is 3-1/4 inches wide running perpendicular to the horizontal line; the bottom of the vertical line should end at the horizontal line's midpoint so you have an inverted "T." Then draw two arced lines from the top of the vertical line -- one connecting to the left end of the horizontal line and one to the right end. You will now have an iron shape.
Measure 1/4 inch down from the place where the vertical and horizontal lines meet. Bow the bottom edge from the corner to the mark, and then bring the bow back up to the opposite edge.
Measure 1/2 inch from either bowed side and make marks at these points. Measure 1/2 inch all around the original tracing and make marks at every inch and 1/2 inch from the top point. Connect the marks so you have the original triangle you traced in pencil and a larger triangle bordering it. Cut out the template.
Place the paper template over your lightweight denim and cut out six triangles.
Pin two denim triangles together along the long curved edge. Sew them together using a 1/2-inch seam. Pin and sew another denim triangle to one of the two triangles you just sewed together. Iron the seams so they face away from the center triangle. Repeat this process for the remaining three denim triangles.
Finish seam allowances with zigzag stitches.
Seam the two halves of the hat together. Use zigzag topstitching along these seams if desired.
Place the hat you just sewed on top of a sheet of paper so there are three triangles face-down on the surface and three triangles face up. Locate the front edge of the hat and place a mark on the paper 1/2 inch down from the front edge of the hat.
Trace the bottom contour of the hat from 1-1/2 inches back from the first triangle's seam to the 1/2-inch mark you just made. Put the hat aside. Extend the 1/2-inch mark so it measures a total of 3-1/4 inches. Draw a curved line from the bottom of the 3-1/4-inch mark to the end of the traced line. Cut out the bill template.
Fold the lightweight denim on your worktable. Place the bill template on the fold so that the straight line of the bill template is flush against the folded fabric. Pin the template to the fabric and cut the fabric for the bill. Cut out a second bill so you have a total of two bills.
Put the front sides of the fabric bill together and pin the outside edge. The outside edge is the curved part of the bill. Sew it together using a 1/2-inch seam. Notch or clip into the seam allowance and flip the fabric over so the seams are not visible. Iron everything so it remains in place.
Sew a zigzag stitch along the seam on the edge. Sew three more zigzag stitch lines for every 1/2 inch to make the bill sturdy. Do not add cardboard to the bill.
Putting the Cap Together
Flip the hat over so the raw edges are exposed. Fold a 3/8-inch hem along the hat's bottom raw edge and pin it down. Iron it in place with the pins still in the fabric.
Fold the bill in half for extra protective thickness and pin its raw edges to the bottom of the hat. Leave an allowance of 1/2 inch so that the bottom of the hat overlaps the bill.
Pin the 1-1/2-inch seam tape to the bottom edge of the hat so it covers the raw edges of the bill. The seam tape helps to absorb sweat along with finishing the hat. Sew a zigzag stitch along the top and bottom edges of the seam tape. Flip the hat so the front side of the fabric is visible and all the raw edges remain hidden. Clip any excess threads.
If you have a 7-inch iron, you can trace that instead of drawing an iron template from scratch.
Feel free to use colored denim that matches your personality.
You need to feel comfortable with patternmaking and have advanced sewing skills.