London Assay Office Tour

On Monday I was fortunate enough to be given a tour of the London Assay Office hosted by Mr David Merry. I have known “Dave” as I call him for many years as he is currently the longest serving member of staff.

Dave took us around the Goldsmith Hall Livery areas first, including the Court Room where the Court of Assistants meet (Board of Directors) and also the main function rooms. Then into the actual Assay Office starting where the packets are unpacked, counted, listed and details entered onto the computer. They are then placed into larger plastic containers for movement around the various departments. The original packaging is reused when the items are completed and ready for return to the customer.

The scraping process (drawing) is not the most frequently used method any longer. Instead most items are now x-rayed to check the metal composition. The result gives a list of the all metals the item contains and the percentage of each metal. These days, in the case of standard 925 sterling silver, the contents would be just silver and copper. Going back 100 years or so it would contain other metals including Gold and Zinc.

Modern gold alloys might contain more than two elements.

Laser marking: The only part of this process of which I was unaware is that marks burnt into the surface of silver do not have to be black. For if the article is given a last pass on low power the marks will change from black to bright. This recent development was I understand invented by Sheila, who heads the laser marking department.

The UK Hallmarking procedure is one of the best and earliest examples of consumer protection. Initially started in Europe it was perfected and refined in England.

Many thanks to Dave Merry and the Assay Office staff for an interesting and informative experience.

Apparently there is a service provided which allows customers to watch their own article being tested and hallmarked. This is arranged by the manufacturer, in this case JA Campbell. Please contact John on 01277 217829 for further details.

Silver Vase resurrection

Some years ago we had a range of Art Deco style Sterling Silver vases in our collection. When we introduced the contemporary appetite collection I discontinued these along with many other reproduction items.

I had a rethink recently and realised we had a lack of all silver vases in the current offering and so decided to ressurect this range as soon as I had a couple of hours spare. This was Thursday 13 March 2014. I decided that the middle size in the range, the 6 inch, would be the prototype for photography. How nice it looked!

I took it along to our local florist – The little flower shop- (near Brentwood station) and asked her advice on the best floral arrangement for displaying them. She recommended two roses. The plan is to collect these on the morning the photography is booked so they will be at their freshest.

These vases are quite simple and relatively quick to make being made of just three silver components. The centre part is  an arc shape cut from a silver sheet and bent around a tapered mandril to form a cone. Sort iron wire is wound around the taper to pull the straight cut edges tightly together.

Flux is then addd to the joint and the cone is heated up to red hot and allowed to cool. After cooling the wires are removed, the taper reheated to red and silver solder applied to the joint. After a further cooling the taper is pickled in hot dilute sulphuric acid, rinsed and dried. The solder seam is then inspected and filed smooth.

Next comes the spinning process. The cone (still not perfectly round) is pushed onto a tapered spindal on the lathe and planished until perfectly round. The top and bottom edges are both trimed true and to height.

The top and bottom spinnings are the next to be spun, there are about four operations in each of these units. They are then soldered on to the top and bottom of the cone. Silversmithing now complete.

Next off to the London Assay Office where all three components are tested and the hallmark applied providing the tests prove positive.

The vase is then returned to the workshop where it is polished using three grades of compound until perfect and bright.

Lastly it is ultrasonically cleaned and packed into its presentation box ready for dispatch.

Please enjoy browsing through my website and in particular at this new addition which will be exclusive to the JA Campbell site and not available anywhere else.

John Campbell

Master Silversmith