I posted this in the beginners forum a few days ago.

http://www.rcuniverse.com/forum/m_8648894/tm.htm

Crank up the heat on your sealing iron and leave it on the stand.

After the iron is hot, place your hobby knife against the base of the iron for about 1 minute to get the blade hot. It may help to remove the blade about half way to keep the handle from sinking the heat from the blade.

Work gently on the epoxy, if it is puddles of epoxy the hot knife should slice right through it.