Blue 50,
The beading you are catching you leg and or buttocks on is the welting cord. There are different types of the welting cord as well. One is manufactured in a pre-fab graining, color, and solid or hollow piping.
The entire welting has a "tail" that is the section you actually sew through. The tail of the welting in the pre-fab style usually has relief cuts approx. every 1/4" so you can bend the welting for inside or outside curves. The second style is hand made by the upholsterer. The "piping" (round tube) is available in different diameters depending on the desired look. Once the desired diameter is selected, 1" - 1 1/4" wide strips of material ( vinly, leather, binding, etc) are cut, wrapped around the piping and sewn together. This method is used to make seat welting, fender welting(using a wider cut), hood to cowl welting etc. To the point on correcting the seam coming apart, buy the upholstery or have the cover made that has the top stitching, or french seam. This will save the bending of the welting back and forth finally giving out, as well as the seam. No more catching your leg or butt on the welting cord, you will have a smoooooth transition in and out across the seat. Alan, definately use a backing material on a french seam. I don't no if you are aware ....... but depending on what you are sewing, there are different "feet" that attach to your machine that are for doing different tasks. I would suggest for doing welting, to get a welting foot, and all other types using a zipper foot. The zipper foot is the one I personally use the most, great for tight quarters, and doing french seams. TIP: use the width of the zipper foot as a guide for the width of each of your stitching lines. My space is limited here without trying to write a technical book, I have been trying to cover at least the basics. Wish you were closer and I would be glad to come by and help out. I hope this helps, just contact me with any questions. Good on you for doing your own interior work!
