Some people lay a piece of cotton or other stuff on top of the coil when they rebuild KPT coils, which is a lot different than a subtank coil. Don't unbraid the Ekowool, it will do it by itself unless you heat treat it. What I mostly use Ekowool for when used in a subtank is I use it to rebuild the original horizontal coils. I have a couple of ST nano tanks that the RBA does not fit in, so I rebuild the stock coils which is very easy.