If you use heat to put it on you are more than likely going to get bubbles in the top piece. While these can be dealt with by poking a hole in them with a needle, they are a pain to have to deal with and can lead to wrinkles and a generally bad looking covering job. The best way to put on a piece of monokote over monokote is to use the "Windex Method". I could describe it here, but there has been a thread on RCU that did an excellent job of telling how to do this. You can find that here.

[link]http://www.rcuniverse.com/forum/m_603331/anchors_603331/mpage_1/key_flag/anchor/tm.htm#603331[/link]

Here are a couple of pictures of planes that I have used the windex method to apply graphics. All of the graphics on both planes are all monokote.

Hope this helps

Ken