What type of mixing cup are you using and what epoxy are you using? Are you thinning it at all?
I am wondering about how you warm it up and the effect that has on curing.
I also like the look of as little finish as possible to protect the wraps, so I've avoided high build recently.
I'm using those little plastic cups you get at fast food joints that are meant for ketchup.
I warm and rewarm using using hot water, don't get it in the epoxy.