On a tangent, this reminds me of some dumb things done by a really smart guy. A co-worker of mine was doing research on what kinds of diagnostics a car’s engine computer could do, back in the late 70’s. They used an LSI-11-based computer in the trunk of the car, in lieu of the electronic engine control computer, because it was easier to reprogram and didn’t have a lot of limitations that the EECs of that time had. This was a single-board computer, in a chassis with other boards for I/O and other features. He kept having board failures, which he had reason to believe to have been caused by boards scraping as they were removed and inserted (which they did a lot).
One attempt to solve this involved duct-taping the back (circuit side) of the cards. He ruined a few cards this way. Evidently duct tape isn’t as good an insulator as it needs to be.
Second attempt was even funnier: he epoxied the backs of the cards.
Result: curved boards. Epoxy shrinks! Expensive lesson. The cards looked very amusing, to those of us who didn’t need them.