Edison Globe Lamp

This project is a little off theme for the blog, since it's not a reproduction of some by gone piece of technology, but it still has a retro flavour so I thought I would do a post about it :)

I was recently house sitting for someone and they had a lamp in their living room with one of those big Edison globes that have become so popular these days. If you're not familiar with them they are incandescent bulbs with very long filaments that glow dimly, and they are generally much large than a normal bulb (though you can get small ones too). The lamp in question had a bulb like this, which is about 10 cm in diameter.

I really like these types of bulbs, they are very attractive to look at and cast a nice warm glow. Actually that's something I have realised I like very much, dim warm yellow/orange/red light. Perhaps that is a nostalgic thing to some extent, back in the day bulbs were generally dimmer, and cast a yellow light. In the last few decades bulbs have become whiter and brighter. I've always hated this, it makes a space less relaxing and more like a hospital. I don't think I'm alone in that sentiment, hence the rise in popularity of these types of bulbs.

I very much enjoyed sitting in the living room under the warm glow of this lamp and decided I needed something similar in my own home. Especially since I've been wanting to get back into reading, but lack of a bedroom lamp has kept me from doing so.

I hate buying new things, so I started browsing online for something second hand and retro (this very nearly led to me buying a lava lamp!), and at one point I ended up on Etsy where I saw a bunch of awesome looking lamps which were Edison globes upwards facing with the socket mounted to a wooden base, under a glass dome. I won’t post pictures because I don’t have permission. They were all quite expensive, but I wanted one, so I decided to build one. So there is really nothing original or unique about this project, I’m essentially just copying something that many others have done. But I thought I would document it all the same.

First I had to find a large glass dome (also known as a cloche). Luckily, they sell one with wooden base for about $15 at Ikea. And after comparing the photos and dimensions, I’m pretty sure a bunch of those $100 - 200 dollar lamps on Etsy were using the exact same dome. It doesn’t usually have that hole in the middle, I drilled that for the wires.

Got an Edison globe from the hardware store, I really like this shape of this one.

And a power cord with an inline switch.

Next I needed a socket, they are easy to find, lots of places sell them. I bought this one. It’s in a “red copper” finish, which I didn’t actually realise when I bought it - I didn’t read the description properly and it looked more yellow in the photo. I actually don’t think I see the colour red as brightly as other people (colour blind) so I wonder how red this actually is, it’s only subtle to my eyes, but still I had expected something different. Oh well, it’s still fine. The knob on the side turns the bulb on or off with a turn.

Now came the tricky part. How to mount this to the base? These sockets have a threaded hole on the back that is designed to be screwed onto a threaded pipe. Typically, at least in all the listed sockets that actually specified this, it’s a 1/8 IPS thread. IPS being Iron Pipe Size. This is an older standard that is still used for some things, and is the same as NPS (National Pipe Straight) which is the parallel equivalent of the more common NPT (National Pipe Tapered). Anyhow, a lot of older style light fittings are designed for this pipe standard. And it seems to be particularly common for lamps. I believe it’s a throwback to when lights were fed by gas, but also worked fine as a conduit for electrical wires when that technology emerged. I could be wrong on some of that, it’s the impression I got as I tried to find appropriate parts and figure out what thread I needed.  Pipe historians feel free to correct me.

What I wanted was some threaded pipe that I could attach to the back of the socket, some kind of flange or mounting plate with a hole in the middle, then I could just drill a hole in the wooden base and secure it from underneath with nut. The ones I’d seen that I liked the look of had clearly used this approach and used a vase cap as the base plate. A vase cap is what goes on top of an old style vase lamp from which the pipe extends up to the bulb socket. Outside of the US these parts are NOT easy to find (at least not in any decent kind of range), and these days postage from the US to Australia is ridiculously expensive. If you’re after this kind of stuff check out https://www.grandbrass.com, they have a huge range of bits and pieces, and depending on where you live the postage may not be too expensive, but I wasn’t willing to pay 30 USD to ship a few bits that weigh about 20 grams.

I did eventually find some threaded pipe, just a small section (on the left), in a hardware that specialises in more old fashioned kind of fittings. Unhelpfully labelled as 3/8 thread, it was 1/8 IPS. I knew it wasn’t going to be long enough, but I bought it anyway, along with another piece that was metric 10mm (M10) thread, just in case. When my socket finally arrived in the mail, it was actually M10 and not 1/8 IPS after all. This was actually good news, because I could get some longer M10 pipe from a local lighting place that sells some more obscure items (on the right).

I still didn’t have a base to attach the socket to the wood. I could mount it directly of course, but it wouldn’t look very good. You would think that finding a brass flange of some sort wouldn’t be difficult. Something for the base of a tap, or a draw handle, or curtain rod, or SOMETHING would be about the right size. Nope. I really couldn’t find anything appropriate. Some ceiling roses for hanging lights would probably work, but it’s amazingly hard to find one of appropriate size and style.

I happened to be picking through a commercial chemistry lab that was closing down and getting rid of all their stuff and I found this bit of pipe with a flange on the bottom (along with a bunch of other stuff for future projects!). The hole in the middle was too large, but I figured I might be able to stick something in the middle, and I hadn’t found anything better.

Also from the lighting store I got these long nuts that are made for joining multiple threaded pipes together. Just so happens that the nuts are just a fraction too large to fit in the centre of the pipe, so I cut the pipe down, cut one of the nuts in half,

then filed down the corners just enough so that it would fit tightly in the pipe. Perfect!

Now I had everything I needed. I drilled a hole through the centre, of the wooden base, another hole through the side,

and drilled out a space underneath.

Putting it together to figure out how much of the threaded pipe I need to cut off.

With the pipe cut down it was just a matter of assembly. Thread the power cable through everything and attach the wires to the socket. This socket uses terminals where you just push the wires into some holes and the spring loaded terminals clamp down on them. To remove them you need to lever the terminals off the wires with a small screwdriver. I hadn't seen this type of terminal on a socket before but it works well.

And that's it, with a nut securing the whole thing from underneath, it's quite sturdy.

Screw in the bulb

Put on the dome

Turn it on

Looks good!

Ahh, that comforting warm glow :)

Well that’s it. A short and simple project but I’m really happy with the result!

What could be better? Well I realised once I put this in my room, that I really want a dimmer switch. I should have foreseen that. It’s a good brightness for reading, but I’d like to be able to turn it down when I’m just relaxing. You can get sockets where the dial on the side of the socket functions as a dimmer instead of just an on/off switch, they just tend to look a bit more chunky as they need to house a potentiometer, and so aesthetically that's a compromise. But it’s an option. Alternatively I could replace the power switch on the cable with a dimmer switch - think you can get inline dimmer switches that also click into an off position, if not I could rely on the socket switch to cut power. I think I’ll actually build a second one with some parts from Grand Brass and incorporate a dimmer switch. I’m also not a fan of the power cord, it doesn’t match the rest of the lamp. I bought some nice red twisted cloth cord which will look much nicer.  Lastly I'm not sure this is really the best way to construct it, when unscrewing the lighbulb often the whole thing rotates because it's just one column clamped by nuts on each side of the wood.  Very difficult to tighten it so much that it can't move at all.  Perhaps I need some washers in there, but I think what would be better would be if there were a couple of small holes in the flange and it was screwed to the wood base - but it's really not a big deal.

Post any questions or comments you might have below. Cheers!