I am one of those that had tried it, and believe me, it was a horrible sounding experience. The experiment did not last long, and I switched the accoustic guitar back to steel strings, and bought a classical guitar.
Dec 09, 2008
Strings by: Anonymous
hello, Although it is safe to put nylon strings on a steel string guitar as the overall string tension is much less than steel, there are many reasons to not do this.
Typical Classical guitars have a wider neck, different scale length, and the nut string gaps are wide enough for steel strings but nut wide enough for nylon (so they would have to be filed).
Also, sound quality-wise steel and classical guitars are designed differently... but with all that said if you wanted to experiment,I'd say go for it, at worst you are wasting only a pair of strings, and some time.
If you get serious about classical/ flamenco I would not allow yourself to adapt to this setup though.