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Arfa Daily Arfa Daily is offline
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Default Old solder paste: the answer


"mc" wrote in message
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"mc" wrote in message
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At this web site

http://www.kester.com/en-us/document...de%20Line).pdf

Kester gives a test for whether solder paste is fresh enough. The test
is to melt a drop of it onto an unsolderable surface and see whether it
forms one ball or several. If it sheds a number of smaller balls (rather
than forming just one), the flux has deteriorated. The failure mode is
flux deterioration.

The funny thing is, I have some solder paste that is 10 years old and
seems to pass this test. I'm going to repeat the test more rigorously.


... And it wasn't reproducible. Apparently, a lot of flux had gone to one
end of the tube.


There ya go then ! So now we all know, and thanks for the update.

Arfa