Hi all!

Hope everybody had a good thanksgiving holiday (our USA members anyway), but have a question about solderpaste life.

We are a low-volume, high mix shop, and we may run 5-20 assemblies, then switch over to another assembly. The solderpaste between these switch-overs may change from a high activity OA to a low activity no-clean depending on the requirements called out on the assembly drawing.

In the past, we have chosen the path, that once solderpaste is opened, it is either used, or scrapped. But looking closely at this policy, we're throwing a lot of paste away, and maybe we shouldn't.

It's no small change, when I've looked at how much we throw away...just wondering now, and I understand the issues of using very old solderpaste, and mixing fresh with new, but does anybody have any guidelines of when they throw paste away, or put it back in the jar to reuse?

I'm about to write some procedures concerning this. I don't think that once the jar, or container is opened, it needs to be consumed all at once, or scrapped. I do think solderpaste is a bit more robust than that (but you might have a hard time for the vendors to say that...hehehe....sorry Mike!). I do think that if good control is maintained, solderpaste can perform as advertised, whether it has been opened previously or not...

Just curious if anybody else has encountered this issue...and adressed it.

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