[TheForge] shrink fit techniques

[Doug Ayen]

"Miller, Ray (GEAE)" sang:
> 
> My experience with shrink fits is in steam and gas turbine assembly
> techniques. 
> In my experience the practice was always, make the dowel bigger than the
> hole, depending on the shrink fit desired, and then shrink the dowel with
> dry ice in a zylene bath and slip the dowel in before it warms back up. Once
> its in, its in, and any errors require drilling.
> 
> Heating a hole to expand it never works reliably, because if you are not
> careful where you start heating, you will actually shrink the hole.
> 
> Ray Miller
> Cincinnati
> 

So, how *do* you heat it properly to get a good fit? Or is the cold method
the only method that is reliable?

--doug