A few years back at another job, saw something like it, also built up on
the sides of the pot and in the pump. Got no support from the supplier,
changed brands, problem solved. A workable solution for a class 2 house
without major requirements for process qualification. But it was still
ugly. Wish we had been able to solve it another way. Maybe someone else
had the same experience and learn a trick. (We were foam fluxing).

> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Dave Pahlas
> Sent: Friday, September 13, 2002 10:03 AM
> To: [log in to unmask]
> Subject: [TN] Black Tar in Wavesolder
>
>
> Technetters,
>
> We are currently experiencing an issue with a black tar-like
> substance accumulating in our solder pot. Samples of the
> substance were sent to the manufacturer of the OA flux that
> we are using and they confirmed through FTIR testing that it
> was thermally cycled flux. The buildup is seen on machines
> using spray fluxers, but is much more prevalent on the
> machine using a wave fluxer due to the added volume of flux
> being applied. We had been using the flux for a little over
> four months with no issues, then the substance started
> showing up even though there had been no process change that
> we are aware of. At first I thought that it may have been a
> result of some spilled Dew, but quickly ruled this out since
> I already know that Dew burns off very quickly in the wave
> with no lasting residue.
>
> The supplier claims that no changes have been made to their
> chemistry but I am wondering if anyone else has seen this lately.
>
> The substance accumulates in the machine around the chip
> nozzle, contour nozzle, nitrogen diffuser rods, etc.
> resulting in the need for time consuming 3-4 hour cleanings
> every two to three shifts.
>
> Thanks in advance,
> Dave
>
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