Rudy
There is no pH endpoint, that is the whole problem. You speak as if a
saponifier were just an unbuffered solution of MEA. From my experience
of over 30 years of using buffered commercial saponifiers, I know they
stop working long before there is a very noticeable drop of pH, and I'm
quite categorical about that. I know of no MEA- or NaOH-based saponifier
which will even think about working at pH 9.8 to 10 with an RMA/RA flux
system. At that pH, you are generating white residues where there is flux.
Brian
Rudy Sedlak wrote:
> When using a saponifier, the available alkalinity is a key part of
> cleaning, not the "reserve" alkalinity...
>
> pH is a measure of available alkalinity...and it is important to
> remember that since pH is a logarithmic function, a drop of one pH unit
> means a drop of 90% of available alkalinity....
>
> Titration is a measure of reserve alkalinity....which might be of some
> interest, but not on the next board that goes through the cleaner...
> Remember, you really will never use all the alkalinity that is titrated,
> so, if we were going to be completely accurate, we would use a titration
> controlled by pH, with the endpoint at the lowest acceptable pH for
> cleaning boards.....if I were using a Monoethanol Amine based system,
> with a starting pH of 11.3, or so, I would use the system to a pH of 9.8
> to 10.0.
>
> Rudy Sedlak
> RD Chemical Company---------------------------------------------------
> Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
> To unsubscribe, send a message to [log in to unmask] with following text
> in the BODY (NOT the subject field): SIGNOFF Technet
> To temporarily halt or (re-start) delivery of Technet send e-mail to
> [log in to unmask]: SET Technet NOMAIL or (MAIL)
> To receive ONE mailing per day of all the posts: send e-mail to
> [log in to unmask]: SET Technet Digest
> Search the archives of previous posts at: http://listserv.ipc.org/archives
> Please visit IPC web site
> http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
> ext.5315
> -----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------
|
