>
> I had a machine shop miss cracks with magnaflux. They didn't clean it well
> enough first. I sold a used head with no crack guaranty. I had to eat that
> one.
Bob brings up a good point here. Magnafluxing is effective only if the person
doing the job is properly trained. The head or block must be completely cleaned
of all oil and grease first. Even paint can mask magnaflux indications. Using
the alternating current method, magnaflux will find cracks that come to the
surface of the part. The direct current method will locate sub-surface defects,
but only down as far as 1/8" or so. And it's much more difficult in
interpretation. These 2 methods use a dry, visible powder, but there is also a
wet bath method used with a "black light" and flourescent solution to show crack
locations. I have been doing these testing methods in the nuclear industry for
20 years, and we need 3-6 months of training to be properly qualified in the
industry. BTW, Magnaflux is a brand name of non-destructive testing materials.
The proper terminology is magnetic particle examination, but like Scotch Tape,
Magnaflux has become the accepted terminology.
Wally / Templeton, MA
53 3100 rod project
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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