Enamelling

As part of the 'Manufacturing and Finishing Techniques' module, the second years had the first of three sessions on enamelling, which will culminate in an enamelled dial for their mini clock.

It's a fun process with with a lot to experiment with! In the first week we learned about different types and styles of enamel, and the basics of applying and firing for different colours and effects. Is was a very interesting session and it was great fun to see what results different types of application gave, and how proper finishing is necessary to stop any damage happening in the future.

A carefully balanced sample ready to be fired.

Going into the kiln.

After being fired the enamels have to cool down before they show their true colour. It was a bit worrying when a 'white' sample came out of the kiln yellow! Fortunately after cooling it looked much nicer. To get this finish, I dusted on two layers, firing the sample after each one. I then used an abrasive stone to make it perfectly smooth across the top, and fired it one last time to give it a glass-like shine.

It only takes about a minute or so to fire!

I was very happy with the finish of this enamelling, but it was much to thick for a practical horological application; probably about 4mm.

After the first session we needed to design a dial to go on our mini clock from last year. we were given measurements of a 40mm dial with a 5mm hold in the middle, but were allowed to change this if we wanted. I deceded to make a chapter ring that was 48mm with a 25 mm hole, and dial feel that held it approximately 18mm from the clock body, so it would be closer to the hands, once they get put on. I used CorelDraw to make an accurately sized design, and messed about with the fonts, numerals and styles. I finally settled some something slightly Bauhaus inspired.

A work in progress shot!

We then all combined our designs into a single file and sent them away to a company that makes special waterslide transfers for ceramics. The waiting began!

In the meantime we made our dials, and got them to a point where they were ready for the decals to be applied. to keep my dial thin I used 0.2mm copper, but in hindsight this may have been too thin as there was slight warping when firing. Luckily it wasn't so bad that I'd have to start again!

They finally arrived, I cut mine out and positioned it onto the dial, then waitied several hours for it to dry completely. We'd seen in exampled that any moisture can make crack-like lines across the dial, and I very much wanted to avoid that!

You may just be able to make out the blue gum from the transfer here

 After drying we slowly presented the dial to the kiln to allow the transfer gum to burn away, then fired it for a few minutes for the enamel to go soft and absorb the ink.

I'm pretty pleased with how it turned out, and am looking forward to having a hand and escapement on the clock. Thanks again to Bridie, our tutor for enamelling!