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RE: proper weld metal notes

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I would like to offer a few reasons why the cost of the groove weld is
higher than fillet welds. It is because there are a few more operations.
First of all fit up is of prime importance.  The root and alignment must be
accurate for a good weld.  If there is a back up bar, it has to be removed
most of the time, then back gouge the root and run a pass or two from the
back side.  Open root full pen welds also need to be cleaned and a cover
pass installed on the back side.  Even if you use copper or ceramic back up
bars, the time to install them has to be accounted for.  Run off tabs also
need to be removed and cleaned up.  The fillet is often more accessible and
a larger molten puddle can be carried.  In a groove weld where the bevel is
narrow, the passes tend to be smaller, and the effort to remove the slag is
a bit tougher.  The weld metal deposited may be equal, but the weld
definitely takes longer to complete.  It is not just the cost of repairs,
because a welder who busts out on more than 5% of his welds is not doing you
a great job.  The repairs need to be a small portion of the weld time, or
you are not making money.

Welding is a bit of an art, and there is much more to it than just turning
on the blue light.  As designers, there needs to be consideration given to
welds that are specified.  They are a large part of the field costs.
Northridge also educated us in the need for ductile connections.  The
perfect connection may not have been designed yet.  

-----Original Message-----
From: Mark Gilligan [mailto:MarkKGilligan(--nospam--at)compuserve.com]
Sent: Tuesday, June 06, 2000 8:30 AM
To: INTERNET:seaint(--nospam--at)seaint.org
Subject: RE: proper weld metal notes


Charlie

It would be interested to see a breakdown that shows why for a multi pass
weldement  "a fillet weld probably costs on the order of $30 per pound of
weld metal; a CJP groove weld on the order of $60 per pound of weld metal"

I would expect that the labor and materials would be similar for laying
down the weld metal.  How much of the cost is the result of having to make
weld repairs?  If this number does not include the cost of making repairs
as a result of UT inspection, then what would be the typical cost for
making such repairs?

Since UT is comonly used on groove welds but not on fillet welds I would
expect that there was some additional cost to make the repairs associated
with the defects found by UT.

Is there a good technical reason to expect that, for multi pass welds, that
the type of defects that can be found by UT do not occur in fillet welds?

Mark Gilligan