Silver Fish

You might notice this post is a slight detour on my (mainly food oriented) blogging road. As you read below, you will find that it does contains a recipe, but one of a very different kind. No, not an entomological recipe as the title might suggest, but an electrochemical one.

It all began when I uncovered a set of beautifully etched silver plate fish knives and forks with bone handles from one of the chests in the dining room. The knives and forks bore the hallmarks H B & H ★ from the Sheffield firm of Harrison Brothers & Hawson, active from 1862 to about 1950. I haven’t been able to date them more precisely, but museum authorities in Sheffield think that the elaborate etched design might date to the earliest years of the 20th century.

fish_cutleryBefore

Not having been used in many, many years, hidden away and stored in a plastic bag, they were in need of some TLC. A dull tarnish covered the silver plate and the bone handles were dirty and requiring a bit of attention.

fish_knife_fork_polishedAfter

Silver plate Restoration
The recipe came curtesy of my chemist son. The quantities can easily be doubled for a larger container.

  • A sheet of aluminium foil
  • 55g baking soda
  • a pinch of salt
  • 1 litre of hot water

Place the foil sheet in the bottom of a deep non-reactive bowl that will hold about 1.5 litres. Place the cutlery in the bowl, making sure the metal makes contact with the foil. Add the baking soda and salt. Pour in the hot water.

An electrochemical reaction is caused when the baking soda breaks down the surface layer on the aluminium foil and frees the aluminium ions. The salt, apparently acts as a quick vehicle for transporting the ions to cause the reaction that converts the silver sulphide (the tarnish) back into silver. On the other side of the equation, the aluminium ions change to aluminium sulfide which shows up as dirty yellow specks in the water. The water will bubble, giving off a slight smell of rotten eggs.

fish_cutlery_removing_tarnish

The process works quite quickly. A ‘tide line’ shows with a few seconds where the blade was submerged. The area near the handle needed to be hand polished to protect the bone. Some web sites that describe the process will tell you to wrap the handle in cling film, another way to protect it.

fish_cutlery_tarnish_line

Several ‘baths’ might be needed to restore the silver plate to its once shiny surface.

fish_fork_knife_detail

Bone handles can be restored by first cleaning off any dirt, then dipping or coating them with oil (preferably mineral oil, but olive oil will suffice). Let the oil sit for a while – overnight if possible. Wipe the oil off and polish.

Now to find an excuse to use them!

* * *

The electrochemical process is explained in full (chemical) detail on the interesting blog, Compound Interest.

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19 comments

  1. I have a aluminium plate which used in conjunction with crytallized washing soda does the exact same thing. I also find it cleans my jewellery efficiently. Love your low tech fix for that gorgeous cutlery. Much feel bizarre finding cutlery in your new home that originates from your old home, but not through you!

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    • It is strange unearthing these things. The institution where I now reside has been here since the late 19th century and various residents over the years have squirrelled things away in chests, drawers, the basement and and outbuilding store rooms. I’ve been systematically going through things, cataloguing them when I can discover anything about them. That is, when I get time to do so! I have a few non-sterling silver pieces of jewellery that I intend to try this method on.

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  2. This is a great post and close to my heart Debi as I just received another lovely set of fish knives and they look identical to yours… amazing. I knew about the tin foil and bi carb soda trick but never knew about the handles. Looks like I have a restoration job coming up. Might put my new set on IMK in February so you can identify them

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    • Hi Francesca, It is a great way of safely dealing with tarnish. The first thing I did, however, was to identify the hallmarks. There is a good on-line source for this: http://www.925-1000.com/index.html
      Also, once identified as a Sheffield manufacturer, I knew of the Hawley Collection of Sheffield cutlery, flatware and tools from manufactures that are now defunct. They also have a number of catalogues from the businesses, so they were able to look things up for me. Google the Hawley Collection if you need to contact them. They were very helpful. Can’t wait to see your shiny fish forks and knives! For the handles (you will see striations if bone), some say submerging them in oil overnight is a good way of rehydrating them.

      Liked by 1 person

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