Hi-- I’ve received several orders lately, and one person specified that I add a C natural thumbhole if possible. I’m still not totally sure I can do that, but I’ve forgotten who that was! If you see this and are that person, please remind me. Thanks
you might wanna ask michael burke how to do it. he makes whistles with cnat thumb-holes.
amar.
Paul,
Drop me an email. I’d be happy to send you my specs for a back thumbhole on both a C and D whistle.
God Bless,
David
I’ve tried it at home with hand drill: Trick is to place it exactly between the B and A holes and to start small, increasing size until you get it right. Learned that trick from Carol Skinner, who had it from her teacher James Conway.
But I have come to realize that every thumbhole drilled brings the Acopolypse and the Beast of Babylon and Armageddon that much closer. There isn’t much room to spare. I would therefore discourage you from actually drilling any.
You’ve been warned, my friend.
right bloom…turning a fine whistle into a steeenkin re…er. 
I did make a whistle with a recorder like double hole for the top hole. This meant you could half hole it very easily. Basically I drilled a small hole - in the position of the normal c#, small… until I hit Cnat. Then I drilled another next to it - also small - until the combination hit C#. So you cover the second hole and you get a perfect Cnat.
Why didn’t I make any more that way? Because I’m happy with oxxooo now 
Paul
He contacted me. Thanks for all the suggestions though.