I've just started playing Tin whistle and am catching on very fast however I hit a snag when doing a C natural (my whistle is in D).

Whenever I blow the note for c natural using the 2nd and 3rd holes the note sound stifled. Ive tried blowing harder like higher octave and blowing softer to no avail. I've read the the alternate fingering for c natural is to cover half of hole #1 for as a beginner I'd like to stay away for half holes for now. Anyone have any tips? Is it possible that my whistle is at fault or is this note notorious for being difficult to hit?

I started using this

I started using this fingering for c natural and it sounds abit better: {]|OXOOOO| (second hole covered)

C natural is almost always

C natural is almost always going to sound more muffled than other notes. The standard fingering of OXXOOO usually works for most whistles but you can also try OXXXOX -- that one sounds better on certain types.

That being said, if it's really not sounding at all then there might be something wrong with the whistle (perhaps the mouthpiece is just dirty.)

This trick, of an alternate

This trick, of an alternate fingering for C natural is interesting. On my D tin whistle, a Walton, I have also noticed that
OXXXXX+ and XXXXXX+ are the same. Sometimes it is more convenient to use the second fingering. Is there any place where all alternate fingerings are written down?

Bruce

I'm not familiar with a list

I'm not familiar with a list of alternate fingerings because they're highly dependent on the whistle itself. Your example of the two ways to play the middle D is a great demonstration of this -- some whistles sound the same when played both ways, some are slightly out of tune or have a weaker tone one way or the other.