I am currently experimenting with different music types and have come across a few pieces that have Bb / Eb and F naturals the Bb just requires a little practice as its all fingers down apart from the A finger open, the Eb is tricky, I am half holeing the D 6th hole which is getting there, but for some reason I am finding the F natural a bit of a problem, for this note I am playing an F and half holeing the E 5th hole, but for some reason its not quite there, does any one know of an alternative for the F natural.
The answer is no, or at least not really. If you’re playing a low whistle, you could try:
xxx xox
and rest the base of the whistle on your thigh to seal the vent hole. But I really don’t do it that way. Like most folks, I half hole B2 and hope the note is sufficiently short in duration that no one notices the difference in tone and volume. You could also cheat and substitute another note or even skip it all together and leave a brief rest (depends on the tune).
I have a few whistles (Burke D, Susato D) on which the fingering xxx oxx gives a usable, fairly in tune second octave F natural. It’s a bit unstable and takes some practice and breath control. But a nice alternative if it works on your whistle and fits in the tune. For the first octave F natural, half holing is the way to go.
Of course, someone else here is going to tell you to just use a Bb whistle and transpose the fingering. But like you, I think the challenge of playing in odd keys and chromatic stuff on a standard D whistle is fun too. So good luck!
Making a thumb hole actally is a good way to play f nats. Some people use them. I’ve taken a cheapie tube and put a thumb hole on it. It would take some getting used to, but it would be doable. Several makers will drill them on their whistles, along with the option of a left hand thumb hole for c nats.
I don’t use either of these options, but some do.
The whistle design makes a difference. I have a hard time half-holing on a Clarke original due to the small size of the holes. If you have one, pick a whistle with large holes.
But like you, I think the challenge of playing in odd keys and chromatic stuff on a standard D whistle is fun too. So good luck!