My Bulbs Are Loose . . . Again!

October 6, 2007 5:29 AM

How can I keep scoreboard light bulbs from working their way loose?

Asking for a friend: "I'm the basketball coach for a small college with an old gym. We have scoreboards in two corners of the gym. Both use light bulbs to display scores, timeouts, etc. Before each game, I have to get on a ladder and tighten many of the bulbs which have worked their way loose since the last game. This takes a good deal of time, and I really don't like ladders. Is there something that can be put on the threads of the bulbs to keep them from working their way out so easily? (My hunch is that the vibration of the crowd, the game, etc. cause them to unscrew.) Googling has only brought up techniques for how to loosen stuck light bulbs. Thanks in advance!"

posted by unclejeffy to grab bag (7 comments total)

I think the heat of the bulbs expanding the sockets might also be playing a role. At least, that's what I think loosens the bulb in the high lighting fixture in my apartment.
posted by HeroZero at 5:34 AM on October 6, 2007

There's a product you can buy called Loctite (in the UK) that is used to glue metal screw threads together. I don't know how it copes with heat and electricity, though.
posted by Solomon at 6:25 AM on October 6, 2007

There's a product you can buy called Loctite...
You definitely don't want to use anything like Loctite, for the simple fact that you need to be able to easily, and safely, remove the bulbs when they burn-out. Never use such product with bulbs.

You're probably correct about the vibrations in the old gym. Have you checked the moorings for the scoreboard and made sure that the scoreboard itself is securely fastened, and not jumping around on the wall with the vibrations? And, are you using the correct bulbs for the board? Considering HeroZero's heat theory, you might be using bulbs of a higher wattage than recommended.
posted by Thorzdad at 7:13 AM on October 6, 2007

How about wrapping the threads in something like Teflon tape to decrease the tolerances and make it a tighter fit?
posted by smackfu at 8:08 AM on October 6, 2007

There is a simple solution to this problem, but it will make changing burned out bulbs more difficult.

All your friend has to do is buy some steel wool at the hardware store, and roughen the metal threads of the bulbs before screwing them into the sockets. It's important not to go overboard with this or the bulb will be so difficult to remove it may shatter if he's not careful, but fortunately, very little roughening does the trick.
posted by jamjam at 8:26 AM on October 6, 2007

I actually would use Loctite (cyano acyrlate) super glue. Not a lot, mind you, but a little dot of the stuff in just the right spot will keep the bulbs in. When you have to replace the bulbs, it'll make it slightly more difficult, but as long as you don't use a lot of the super glue, it should be fine. Perhaps try it on a bulb or two first to be sure?
posted by fvox13 at 12:07 PM on October 6, 2007

Can you just use a light bulb changer (on a pole) to quickly tighten them instead of climbing and moving a ladder?

Note that overtightening bulbs -- which you may be doing to compensate for the looseness -- can destroy the ability of the electrical contacts to make a good connection. So you get into a cycle of tightening, losing the connection, and tightening further.

You could also observe whether specific sockets are looser than others. WITH THE POWER OFF, try lightly crimping those sockets with a pliers. You will probably get a slightly elliptical shape, but that may be enough to hold the bulbs in place and make an electrical connection.
posted by dhartung at 3:27 PM on October 6, 2007