Alien Epoxy (Fallout 3)

Alien Epoxy is an item which is added to Fallout 3 in the Mothership Zeta add-on.

Uses
It can be used to increase the Condition of your currently equipped weapon, up to a maximum of 100%. The percentage repaired depends on the player's Repair skill:

cannot repair armor or clothing.

Trivia

 * An "Epoxy" is a chemical that forms a tough compound around the applied area. This fits, suggesting that the epoxy fills in cracks or faults in the weapon.