Here is a safe clean way to remove Ultracote paint left stuck on balsa.

1st..... locate or buy some (SUPER STENGTH CLEAR PACKAGING TAPE) I used Staples brand in this demo.

2nd..... Tear off and lay over paint to be removed, stick it down good - use plenty of pressure but not so much you damage the balsa wood under paint.
3rd...... Begin to lift the tape slowly and "Walla" paint will stick to tape. If it does not work in an area try using it again but this time turn the tape 90 degrees to the last application. I have used the same piece of tape many times until an area was clean.

Note: I do not know if this tape will work on Monocote or 21st Century coverings. Let me know if it does.
I appied some very low heat to the Clear Tape with my monocote iron (setting just above the "low" mark) and I had mixed results. Sometimes the paint lifted better and other times it seemed like it interfeared with the glue of the tape. Also I noticed this process will not work on stuck to fiberglass paint/adhesive.

Hope it works for you Good Luck!
Doug Greer AMA 233582 IMAA 41766
p.s. I am having problems uploading my pictures so if you do not see them- I'll try to repost them.