<VV> Two helicoils in line?

[BobHelt at aol.com]

Sure it works just fine as explained in my book, THE CLASSIC CORVAIR.
Regards,
Bob Helt
 
 
In a message dated 2/22/2012 8:45:00 A.M. US Mountain Standard Time,  
larry at schuberts.com writes:

The  helicoil inserts
are only about half the length of the threaded part of the  stud, and I'm
wondering if it's possible/smart/insane to drill and tap the  hole far
enough to twist in two helicoils, one behind the other, to give  the stud
that much more thread to grab. I've never tried this trick  before,
although I've used dozens of helicoils of all sizes. One is tempted  to
think that the threads tapped for the helicoil should  automatically
force the helicoil inserts to line up in such a way that the  stud
threads wouldn't get "confused" transitioning from the first insert  into
the second insert (if you get the sense of what I'm trying to  describe.)
For once, Google isn't providing any help with this question, so  I'm
asking for your experience and  expertise.