We’re a little surprised the No-Clean Flux Remover – VeriClean™ (#MCC-DC1) works at all. This cleaner is siloxane- based and is the best choice for silicone conformal coatings. But the Humiseal 1B31 is an acrylic. According to the Humiseal product spec sheet, “HumiSeal 1B31 is a fast air drying, single component, acrylic coating that provides excellent moisture and environmental protection for printed circuit assemblies.” Acrylics are best removed with the Lead-Free Flux Remover – PowerClean™ (#MCC-PW210A) or the Heavy Duty Flux Remover – SuprClean™ (#MCC-SPR) both of which are fast-drying, nonflammable, high Kb flux removers. You’ll find them much better choices for cleaning the thin, hard acrylic coatings. Try one of them and you will see the results are much faster and better.
Be advised the one type of confiormal coating we CAN’T remove are the “thermoset” materials, which take a heat-cure process, such as epoxies and Paralene.