Dean Hoffman wrote:
On 1/16/05 10:52 PM, in article
, "frank1492"
wrote:

There is a stainless steel bolt (about 3/16 diam) that
is threaded into the center of the motor shaft in an old
dishwasher that I am repairing. In order to remove the
impeller and other parts for replacement, it was necessary
to unscrew the bolt. Having no success, I ground the head
off, thinking I could then liberally apply penetrating oil and
eventually get the bolt out by turning it with a vice-grip.
Despite numerous oil applications and twisting to the
breaking point, the bolt has refused to unscrew.
It is very important that the bolt not break off, as it
would be very difficult for me to redrill the hole
concentrically.
Would it be worth trying to heat the bolt with a propane
torch? How should this be done, and what would the risks
be? Would there be increased risk of shearing the bolt off
after heating (assuming it still won't yield at the threads)?

Some cut.

You need to heat the motor shaft instead of the bolt. The
idea is
to
expand the shaft so it will release the bolt. It might help
to heat
the
shaft then dump water on it to cool it rapidly. Reheat it,
then try
to
unscrew the bolt.
Propane might not be a hot enough fuel. I'm used to using an
acetylene
torch for these type problems. There is something called a
mapp gas
torch
that is fairly cheap and would produce a hotter flame than
propane.

Dean

Never found that to be a necessity, though it's faster heating.
It's also hot enough to do damage if one isn't careful, esp to
winding insulation, etc.,. even with propane.