Ivor and Olive Lewis on fri 17 sep 04
Dear Vince Pitelka,
Good old Dye Penetrant Disclosure. Sorts out the men from the boys ! !
Slag inclusions and porosity are just two potential hazards. To get up
to "Class One" for Lloyd's Insurance on pipeline work the allowable
limit for either, as I recall from memory going back forty five years,
was "Zero". Anything that showed on the X-Ray film had to be chiselled
out and rewelded.
Our final in the "Ordinary Class" at Sheffield Tech (as it was known
then) was to make a double "V" in a plate and take sections from it.
These had to bend round a "2T" bar. The killer with this test is
"Undercut", the merest suspicion of a notch stress raiser at the edge
of the weld would guarantee fracture. It also was a good test of "Root
Penetration"
"Inclusions" are never "Flukes" If it was trapped slag then you would
have missed it on inspection of your own work. Slag from a well laid
bead will usually lift without the need for the Pick. If it was
porosity you may have been travelling fast or had higher or lower than
needed current, or a slight slag trap. Damp electrodes sticks can
cause porosity as well.
Have you ever tried salvaged welding slag as a ceramic glaze?
Best regards,
Ivor Lewis.
Redhill,
S. Australia.
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