I would usually agree with Ed's statement on tin content dropping. I have many years of Kester Solder Analysis Reports, option C, that support that statement. But, for the
last four months my tin content has ran 63.16, 63.42, 63.24, and 63.4. No pure tin was added during this period, only virgin solder. Sure has got me scratching my head.
Gary Camac
Ed Popielarski wrote:
> Yordan,
>
> Deviation from 63/37 can cause increased solder shorts in a wave soldering
> machine. At 63/37 (eutectic) the melt point is minimum, and there is no
> plasticus range. As you drift from there the melt point increases and the
> plastic range increases. This is why hand solder is preferred at 60/40...
> there IS plastic range and makes it easier to judge the joint as you solder.
> This is also the main cause of "frosty" joints (I hate to say "cold" since
> it is a very inaccurate term).
>
> Another thought to add to the mix is the accuracy of the lab. I recommend
> using either Alpha Metals or Kester to do the analysis (Type C which is the
> "whole enchilada" variety) and perhaps to rule out other variables discussed
> in other's postings, take a few samples, from the static part of the pot,
> from the wave after running at temperature, etc. If all the samples come
> back relatively the same, then you are good to go, but if one or two stand
> out, there could be something worth looking into.
>
> Additionally, (yes, another variable) the tin is usually the element that
> drops, not the lead. This has me wondering as well. Why?
>
> Have a safe and happy holiday!
>
> Regards,
>
> Ed Popielarski
> QTA Machine
> 27291 Jardines
> Mission Viejo, Ca. 92692
>
> Phone:949-581-6601
> Fax: 949-581-2448
> Cel: 949-337-2578
>
> WWW.QTA.NET
>
> "Thank God for America...
> before it's too late!"
>
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