After the beard on King Tutankhamun's iconic burial mask was knocked off during cleaning (or removed because it was loose), it was quickly glued back on with epoxy, resulting in a crappy and permanent fix to the 3,300 year-old artifact.
From the AP:
"The mask should have been taken to the conservation lab but they were in a rush to get it displayed quickly again and used this quick drying, irreversible material," the conservator (at Cairo's Egyptian Museum) added.
The conservator said there is now a visible gap between the face and the beard. "Now you can see a layer of transparent yellow." (image below)
Another museum conservator, who was present at the time of the repair, said that epoxy had dried on the face of the boy king's mask and that a colleague used a spatula to remove it, leaving scratches. The first conservator, who inspects the artifact regularly, also saw the scratches and said it was clear that they had been made by a tool used to scrape off the epoxy.