Your Double welt equipment and process?

[Mike]

Checking my understanding, so do you end up with a double cord covered by three layers on each side cord?  Guess you could sew the two layers down the middle and trim one of the layers back close to the center seam , on each side of the first seam, before sewing the final seam.  Then that would give four layers ( this assumes the final seam is sewn on top of the first seam.

I wish i hAd a pic. DB picture 2 normal piping welts sewn together laying top to top eith a selvedge edge on the right and left

[Mike]

I had tried to sew 2 side by side with 1 selvedge with 4 layers. But i think it was stephen here and seem more at carrs forum where i learned this tecnique from