What strings for half size guitar?

[lincolnblue]

My wife's colleague has asked me to change the strings on her daughters half size acoustic...nylon string. Can I just use normal nylon strings and cut them to size?

[thermionic]

I've been wondering about this because I bought my niece a nice 3/4 size guitar from Cranes and she's still on the original strings after a few years...

String tension is proportional to mass per unit length (i.e. gauge) and proportional to the square of the scale length (for a given frequency).

A quick google gives 63cm scale for full size and 52cm for a 1/2 size classical. So, equalling the tensions the mass per unit length of a string for a half-size guitar should be approximately 1.5 that of a normal-scale instrument. Mass per unit length is proportional to the string's cross section, or the square of the diameter (i.e. gauge). After a bit of algebra, I'd say you have to multiply the gauge by 1.22 to get the same tension.

Just as an illustration/analogy, for steel strings that would be the equivalent of going from 10-46 to 12-56.

[ICBM]

My wife's colleague has asked me to change the strings on her daughters half size acoustic...nylon string. Can I just use normal nylon strings and cut them to size?

Yes, but I'd use Hard Tension not Normal Tension, or the strings will feel like rubber bands and be difficult to play in tune. (Classical strings are sold by 'tension' rather than gauge.) If it's a really short scale, maybe even Extra Hard Tension - they won't feel hard to play because the short scale will reduce the actual tension.