ouch! scraped some foam

Anybody have any good home remedies for a scrape in the foam? I was putting the finishing touches on my shape and my little mini hand planer was dull. ( I forgot) I put a scrape by my stringer a couple inches long. What can I use to patch it? Hopefully I won’t have to run all the way back to the surfboard supply store. How about flour mixed with water and white acrylic paint? Spackle? Any ideas?

lightweight non-shrinking spackle…let it dry really well before you glass. also if you plan on painting the board it will be a different color. austin