Have you considered using couching for the piping? Basically it is zig zagging over a heavier yarn or thread to hold it down. You would need to use a fairly tight zig zag to hold up to preschoolers but it would be much easier than piping.
Edited to add: there are lots of videos out on YouTube for how it is done. Also, depending on the size of thread a couching foot may not be necessary. Easier but not necessarily needed.
Last edited by Cactus Stitchin; 01-19-2018 at 05:46 AM.