What is this light bulb?
May 29, 2020 12:03 AM   Subscribe

The three light bulbs over my bathroom mirror have burnt out. I've scraped all of the dead moths out of them and I'd like to replace them. What google words do I use to find these bulbs for sale?
posted by bendy to Home & Garden (19 answers total)
 
Best answer: How long is the bulb?

The Type-J bulbs for the old Halogen Torchiere lamps are 4-3/4" inch long. And those have more of the little circle attachments on the filament, so I'm guessing it's not one of those.

In this assortment of double-ended 120V halogen bulbs, there's a Type-J Short, which is 78mm long (3.07" inches) long, and has two of the little circle attachments like the photo. So that seems plausible if it's the right length as your old bulbs.

As always with halogens, don't get skin oils on the bulb because the oils stress the bulb as it heats. Instead, manipulate it using paper towel or gloves or something.

To understand the codes: https://en.wikipedia.org/wiki/Halogen_lamp:
The length of any two-ended cylindrical bulb must be specified separately from its form factor code, usually in millimeters, as must the lamp's voltage and wattage— hence, T3 120 V 150 W 118 mm means a double-ended tube-shaped bulb with a diameter of 3/8ths of an inch that operates at 120 V and is 150 W and that is also 118 mm long.

An R7S is a double ended, recessed single contact (RSC) linear halogen lamp measuring either 118 mm or 78 mm. Some less common lengths are 189 mm, 254 mm and 331 mm. These lamps have a T3 shape on an RSC/R7S base. These can also be known as J type and T type lamps.
posted by sebastienbailard at 12:27 AM on May 29, 2020 [3 favorites]


Note that there appear to be LED versions of the R7S bulb. Ideally they would fit in the same lamp and provide comparable levels of light as their halogen counterparts. Whilst also running cooler, lasting much longer and giving you many more Lumens per Watt. This is not always the case - so read any reviews carefully if you go down this route.
posted by rongorongo at 12:54 AM on May 29, 2020 [1 favorite]


Response by poster: The Type-J bulbs for the old Halogen Torchiere lamps are 4-3/4" inch long.

I remember always being warned that they were going to catch fire. Thanks Target!!

I've now lost the bulb but my measuring app says that the gap it goes into is three inches long.
posted by bendy at 1:12 AM on May 29, 2020


(Your picture is marked as adult content, so those of us without a Flickr account can’t see it.)
posted by Tell Me No Lies at 1:20 AM on May 29, 2020


Response by poster: (Your picture is marked as adult content, so those of us without a Flickr account can’t see it.)

That's because I originally named it crackpipe. It's now called lightbulb.
posted by bendy at 1:30 AM on May 29, 2020 [2 favorites]


Still no joy.
posted by Tell Me No Lies at 1:35 AM on May 29, 2020


Response by poster: I had to clear my cache. Try that.
posted by bendy at 1:39 AM on May 29, 2020


I can't see it either.
posted by amtho at 1:41 AM on May 29, 2020


Response by poster: Oops, sorry about that. I was able to see this while logged out. Any luck?
posted by bendy at 1:48 AM on May 29, 2020


That did it. Thanks!
posted by Tell Me No Lies at 1:55 AM on May 29, 2020


It does look like a halogen bulb.

Can you see any notations on the fixture at all? Sometimes those have bulb specifications written on them.
posted by amtho at 2:49 AM on May 29, 2020


Best answer: I've now lost the bulb but my measuring app says that the gap it goes into is three inches long.

So that would be a 78mm bulb; the contacts in the fixture are spring-loaded so those extra 3mm are inconsequential.

As you can (probably, Amazon searches can yield different results based on your region) see in the link sebastienbailard posted, several of the LED versions are thicker than the halogen originals; some even not just a little thicker. The 'COB' versions tend to be the best match regarding size, but there's no guarantee that any of them will actually fit with metal or porcelain parts of the fixture not offering sufficient clearance for anything thicker than a standard halogen.
posted by Stoneshop at 3:10 AM on May 29, 2020


Best answer: I agree with sebastienbailard that this is a Halogen Type-J. In addition working from the picture this would be a 78mm J-Short.

This is the closest analogue from sebastienbailard's link, but I'm sure you can find it elsewhere.
posted by Tell Me No Lies at 3:11 AM on May 29, 2020


Best answer: I remember always being warned that they were going to catch fire.

Not directly, but due to the high temperatures the quartz envelope would be affected by skin oils (actually, any deposited contamination) and become quite prone to spontaneous breakage. At which point parts of the white hot filament may get ejected and cause fire elsewhere. Hence the warning to keep the fixture's cover glass in place.

With LED replacements the temperature aspect is as good as negligible.
posted by Stoneshop at 3:21 AM on May 29, 2020


Response by poster: You're all awesome.
posted by bendy at 4:38 AM on May 29, 2020


Response by poster: I ordered them on Amazon and, as usual, I sent it to myself as a gift. The message is "Yooooouuuuu light up my liiiifee."
posted by bendy at 4:47 AM on May 29, 2020 [6 favorites]


Best answer: Halogen is hot and not super efficient. Next time, maybe just replace the fixture, usually not terribly difficult. LED is so efficient, and I hate specialty light bulbs.
posted by theora55 at 10:43 AM on May 29, 2020


Response by poster: Sadly I'm renting - would love to replace the fixture. Moths catch fire in them frequently and the glass covers fill up with moth ash.
posted by bendy at 6:36 PM on May 29, 2020


Response by poster: The bulbs arrived yesterday and during my inevitable period of procrastination they'll sit on the bathroom counter but I will deploy them soon.

Thanks y'all for your help.
posted by bendy at 7:34 PM on May 30, 2020 [1 favorite]


« Older What's the deal with the baseball union?   |   What's wrong with my bed? Newer »

You are not logged in, either login or create an account to post comments