I'm going to show what can happen with Super'Phatic. I glued down the bottom longeron and placed a dark grey magnet over it to hold it down after cleaning up what I thought was all the excess with a cotton swab. After a 20 minute cure, the magnet refused to come up. You can see how it ripped off part of the balsa fuselage side at that join. Grumbling to myself, I carefully saved the damaged piece with some careful X-acto surgery and reglued; I put down a small piece of plastic wrap before I set the magnet back for its clamping action.