I want to cut round clean-out doors in my birdhouses and wish
there was a hole saw with a very thin kerf, like a metal bandsaw
blade (.035" thick).

All the hole saws I can buy have about .100" kerfs, which is too
much to "fudge". Cut with a band saw works well, but, it's not a
central hole.

Even have the idea to try to make one from a 1 1/16" wide metal
band saw I have... I'd gently feed it in a drill press.

Al