Hi Gregg! Brian provided a great summary on the aging aspects of the flux
core - I can provide some information on solder. There is a "default" shelf
life for flux cored solder due to the oxidation of the solder alloy itself.
All solder alloys oxidize over time so there will be a point where it would
be prudent to no longer use an "old" flux cored solder roll. I have been
"collecting" old flux core solder rolls from various areas of our
manufacturing operations as "spring cleaning", part number revision, and
facility re-layout activities happen. Its has been a good way to keep
various odd solder alloy, flux combinations, and wire diameter variants on
hand. We just put one of those older rolls into the recycle bin - I had an
old Alpha Metals 10Sn/88Pb/2Ag solder roll with a "energized rosin" core
from the 70's that finally accumulated a thick enough oxidized skin that
inhibited soldering. I believe most of us would consider 30+ years of use
as indefinite shelf life!

Dave Hillman
Rockwell Collins
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             "Gregg A. Owens"
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             05/05/2005 02:30          [TN] Flux Cored Solder Shelf Life
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TechNetters:

A student of mine has asked, what is the shelf life of flux cored
solder?

In reviewing J-STD-001 and J-STD-004 I can't find any specific guidance
or requirements from the Standards. I know newer rolls of solder
(depending upon the manufacturer) have date codes and expiration dates.

However, they have a wire solder spool still being used today that was
entered into their HazMat system in 1998 (no actual record of the
precise date of manufacture). The wire spool is removed from their
HazMat system when needed to uncontrolled/undocumented working
environments within their facility. Since the standards don't specify a
shelf life, what is considered best industry practices or is there a
Standard dealing with this issue?

Thanks for your responses.

Gregg A. Owens
Master IPC Trainer
Executive Director
Manufacturing Technology Training Center, Inc.
Mira Loma, CA 91752 USA
www.mttc-inc.com
815
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