Martin, it does appear that it could become a paper weight, as per Dave's suggestion.

With the cost, generally, of these lenses still quite cheap and reasonably plentiful, get another one, or something better.

Once on a photographic hike, were quite cold and wished to make a hot drink, the person with the stove was kilometres away, so we made a fire using winter sunlight and a 50mm lens focusing sunlight on some loose cotton fibres to get a flame, works a treat, perhaps you could use it for something similar?