It's time to change the strings on my viola, just wondering whether strings you have had knocking around a while (15 years or so ) are still OK since they haven't ever been under tension or touched by finger oils, or do they still degrade sitting in the case?

I don't know, but would venture to suggest that there's an extremely straightforward way to find out!

Unused strings do still deteriorate; how much will depend on how good they were to start with. But you have nothing to lose by trying them out.

I left spare strings in my case once, for quite a few years. When I came to put them on, they really were unusable. It seems that my case at the time was not very weatherproof, and the strings were rusty!

I'm with Discopants on this one - stick 'em on and find out !

I am scared of them going pop in my face,. Shall give them a whirl at arm's length and see how we go. They are Dominants, so I gather they are toward the indestructible end of the market.

I reckon they'll be fine. The windings might be a bit tarnished, but that's about it.

If they are metal or synthetic core they are very unlikely to break. Gut core ones like Eudoxa might be more prone, so take care! You could always put on some safety glasses.