Edwardian Brass Lock

We bought a Edwardian brass lock without a key. We considered it a huge risk rather than an amazing bargain at £30. It was on a French market stall in Dorset, UK. A local locksmith said he could make a key but it would not be cheap and would cost a lot more than we paid for the lock. He wouldn’t give a price.

When I got home, I did some online research and another locksmith quoted me £350 for the first key and £200 for additional ones. The turnaround was 6 weeks. Had we bought a complete Dud?

I therefore thought I’d have a go myself – how hard could it be?

The outer casing is made from polished cast brass. We don’t think the knob is correct for the lock (c. 1920?), so we will keep an eye open in brocantes for another set. The key hole cover is also missing. I might make one of those if I don’t see a suitable one. We’ll leave the casing un-polished as the patina is great.

When I unscrewed the lock, it was packed solid with mucky cobwebs, wasps, woodlice and beetles. In the past, someone had oiled the lock without cleaning out the dust. The oil had then congealed solid, seizing the lock. This lock has a seriously strong spring and would have taken strong hands to work even whilst in good condition. Any friction from the sticky oil would have been very detrimental to this locks performance.

I took a wire brush and some 1200 grit sand paper to some of the internals. Some pieces were brass, some steel and others cast iron. Initially, only a couple of bits showed any signs of wear. It was definitely a mighty bit of kit. Now everything is cleaned and essential surfaced smoothed, this lock has some serious ‘snap’. It is very keen to trap skin and bite at every opportunity. Clang! Clunk!

It soon became obvious the key for this lock wasn’t going to be pocket sized. This lock needed a massive key of Château sized proportions.

I started by making two small plates of stainless steel, that fitted around the ‘barricades’ in the lock. If you scroll through the gallery you might be able to see them?

I’d made the two plates with only about 0.5mm clearance. Whilst loose these two pieces easily passed over the internals of the lock.

However once holes were drilled in an 8mm stainless steel bar and the and two bit inserted; it became obvious the manufacturing tolerances of the lock weren’t perfect.

The main problem was the hand made central pivot bearing that the key sits in was 0.21mm off centre. The 8mm stainless bar was a snug fit for the 8.09mm hole, whereas maybe the original key might have had more slack?

A small panel beating hammer and a pair of long nosed pliers were used to slightly adjust the central pivot but basically the key was opened up with a selection of swiss files and a 1mm drill. Maybe the shear force needed to turn to key had distorted the centre pivot over the last 100 years?

The length of the rotating plates has to be precise. Whilst turning, the plates have to clear the sides, clear a cut out, then hook against another bar to move the bolt. We are talking about 0.05mm. It also means if the key wobbles, it won’t unlock. Which likely means the original key was probably exactly 8mm diameter too?

After welding, the first attempt at key making proved to be moderately successful but there was obviously room for improvement. Frustratingly, you had to tilt and jiggle the key fractionally to get it to work 100%. So I started again with a one piece rotating part.

Second Attempt

Having it in one piece actually took up a lot of slack and meant that I discovered 2 almost invisible extra metal guides that had almost worn away. However, they still required extra grooves to be filed into the key.

I also cleaned the lock mechanism further with an electrolysis tank to get out the last remnants of rust.

I welded a nut to the shaft to set the height that the key get inserted into the lock.

This is the finished key in the lock. It’s basically recycled from an old 1970’s stainless steel bonnet prop. I’ve saved myself a few hundred quid. The lock and key now owes us £30, some gas, a little scrap and about 8 hours messing about. -bargain!

We have a silky smooth, fully working Edwardian key & lock (c. 1901-1910) that is perfect for when our house was probably built circa 1890 – 1910.

To open the lock fully, you have to turn the key 3 times. To fully lock takes two turns. You can half lock and there is a small separate dead bolt. This lock might be old, but due to the various intricacies and shear power of springs it would make it an easier proposition to take a axe to the 1.5″ thick solid oak door.