Does anyone know where I can get 3/16 to 1/4"vinyl/rubber/plastic flexible L angle? Fourmost has everything but plain old L angle.

Thanks
Jeff

What do you need it for?
Have you thought of making it with silicone, the same as silicone hinges?

Home Depot or Menard's in the drywall department. Drywallers use different, strong yet flexible L bead, it will be near the mud.
Drywall specialty warehouse will carry more of a variety of size and maybe flexible L angles for ceiling grid systems. Light weight stuff as well.
Hope this helps you,

Jay