Golly Corner: Yellowing of 1993/94 Set

YELLOWING OF 1993/94 SET

At the Quorn swapmeet of Autumn 2000, after looking at the large 1993/94 brooches for sale it became apparent that many from the set had started to yellow where they should have been white. It was most apparent on large areas of white such as those found on the pilot and the chef. However, the rugby player's ball and other smaller areas also showed signs. I put this down to them having been stored in sunlight. On arriving home I checked mine and convinced myself that the whites were still white. However, in August 2001 I had cause to check again and found the truth was quite different!

Considering the pre-war fruits have survived in excellent condition since 1932 and yet the 1993/94 set have started to deteriorate so soon after manufacture, I set out to try and understand the problem and sought opinions from the sources mentioned below. Please note that no firm conclusion or evidence has been reached. However, it provides food for thought, and hopefully will help you consider carefully how best to store yours.

Anybody who can tell me how their set has faired and how they store them may help to reveal the cause.

Sources

With thanks to everybody who has contributed.

What is happening?

The Bizz Badge Company say that the 1993/94 set were steel stamped badges with epoxy coating. After 5 years or so, epoxy will start to discolour especially quickly in direct sunlight.

Colin Dodds offers an explanation that the most likely causes are oxidation of the coating causing yellowing, with contact with air being a cause almost impossible to stop! The oxidation could well be speeded up by light, as for example the rapid browning of old newspapers which needs air and light to go rapidly. The plastic coating is set by a catalyst or more strictly an accelerator. If too much accelerator is present, then it can help in continued oxidation of the coating. This could also explain why some badges seem OK after an equal length of time. It seems to affect some batches more than others.

What factors might affect the yellowing process?

What other sets can we expect to find this problem with?

The Bizz Badge Company state that the 1996 Limited Edition were a better quality production than the 1993/94 set; photo etched using gold plated brass and epoxy.

Colin has observed that the yellowing also seems to affect the Pro-Pat design coating.

Conclusion

Without several different examples of both horizontal and vertical backstamps stored in different conditions over a period of time (in original bags, in the wrong original bags, in the dark, in the light) it is going to be extremely difficult to be sure if the cause was in the manufacture of some but not all brooches and whether storage can only at best slow down the visible signs of ageing.

Since seeking peoples' opinions I have decided to remove my set from plastic bags but keep them in the dark. Others have expressed the view that without displaying their collection on a wall for all to admire, then the point of collecting is lost. From what I have heard, these people seem to have faired best so far!


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Golly Corner: Yellowing of 1993/94 Set / revised September 2001
Photographs & Text Copyright Liz Prigg © 1998–2009