In the past I have used Loon Hard Head and Delta Ceramcoat Varnish which are both water based polyurethane. Over time they both crack. That isn't a problem if you lose them to a fish before it happens. I have also used Devcon 30 minute and BSI 30 minute two part epoxies. They resist cracking but discolor over time. The latter is not that much of an issue. Lately I have been using Flexcoat Gel Lure Coat epoxy. It costs more than the Devcon and BSI but at the best I could coat 10 poppers using Devcon and BSI with one batch of epoxy and then only if I kept them cold to retard the curing process. With the Flexcoat I can coat 20 poppers without having to cool it and could probably coat more if my setup permitted it. The Flexcoat does require turning for a much longer time and I place a fan to blow the distasteful odor away from me while I am using it. Flexcoat is remarkably clear epoxy and I like the graduated reusable syringes which permit a better dialing in of the correct 50/50 proportions by volume.
carlz: Strange!? I have never had a hard foam popper become water logged even when the clear coat and paint came completely off through rough use. Were you using Wapsi or similar commercially available hard foam or using something you repurposed from another source?