I have a boom lamp from CB2 that's about two years old in my living room. The angle between the arm and the stand is adjustable. Unfortunately, the mechanism that holds the lamp up (I'm afraid I don't know the correct term for it, but you can see it below) seems to have stopped working and now within a day or two of my adjusting it, it succumbs to gravity and the lamp head falls to the lowest possible setting. Is there anything I can do to keep the head of the lamp up short of epoxying it in place?
EDIT: at the risk of outing myself as a complete noob I have attached an image below with the component I plan to fit the washer to circled in red. The washer will go inside of the joint mechanism so that it's not visible when the lamp is fully assembled.