Restoring a 150

The 150 is an iconic design and probably what most people would think of when they picture an early telephone. It was introduced in 1924.

This page shows a detailed restoration on a 150 type candlestick telephone. These phones are now quite expensive in good condition (which I could not afford!) but sometimes come on the market in a poor or incomplete condition at a much lower price. This one was very rusty, but complete and untouched.

It's always a problem to know how far to go with a restoration, and generally I would agree with the modern trend to try and retain as much original finish as possible. However this example had lost so much finish and was very rusted and pitted, so I decided to strip it right back and finish it to look as much like it might have done when it was in use.

Here is the rather sad 150 candlestick as purchased from Ebay.
	Undoing the screw on the base allowed the 'works' inside the shaft to be withdrawn. The cables were fed carefully though the grommet. The case iron base was rusted to the pressed steel housing, but a gentle tap with a brass hammer removed it!
These are the parts inside the shaft (cradle switch and terminals) and the fixings for the mouthpiece. They were if pretty good condition and only required light cleaning.
	As I have a lathe, I mounted the main body between centres and spun at about 1000 RPM. Emery cloth soon started showing some clean steel. A mixture of files, emery and an abrasive flap wheel (mounted in a drill) gradually cut back the rust until the body was clean and ready for painting. If you don't have a lathe this could all be done by hand but would probably take a bit longer.
I used a car filler/primer spray as a first coat. (Shocking colour!). This smoothed out any minor pits, avoiding cutting the metal back too far.
	Finally I sprayed with three coats of semi-gloss black car spray, cutting back after each one with T-cut to get a good finish. Other small metal parts were given a similar treatment.
The mouth piece had a chip. Not bad, but it did spoil the appearance.
	As the chip did not go far back, I carefully mounted the mouthpiece on the lathe and turned it back using a sharp tool. I then polished it. I think the result is pretty good.
The receiver was in good condition and only required a clean and polish.
	The receiver and line cords were complete, but very dirty and stained. On the basis that I could probably get replacements if it all went horribly wrong, I dunked these in soapy water and gave them a good scrub! A lot of dirt came out!
When they were dry, they came out a slightly lighter colour, but uniform, much more flexible and still intact. Probably nearer their original colour.
	This 150 is of the type used on manual exchanges, therefore it does not have a dial. One could be fitted if required. The space where the dial can go is filled by a blanking plate which has a space for the usual dial label. The transparent cover was very dirty, but cleaned up well with some methylated spirits. The ring that held it in place however was cracked and misshapen. On cleaning this was found to be brass. I silver soldered it back together, but the result is not very good. I will have to make new one by trepanning it from brass sheet. To complete the phone, I made a new label in the correct style using Coral Draw.
When all the parts were restored to my satisfaction I reassembled the phone. Here is the finished result.

One of the most useful things I did during this restoration was to take close-up digital photos at every stage. I took about 100 altogether! As well as being a record of the work, it enables you to check back on things. For example, when I reassembled the ear piece I could not remember how the cord was knotted to the magnet yolk. One quick check back to the photos and the method was clear.