Tom, you might check with the folks who potted the transformer to be sure that they properly mixed and cured the epoxy. If the epoxy is turning soft it usually is a case that it was improperly mixed or cured.
(my experience)

Ron Dieselberg
Trainer
CMC Electronics Cincinnati
[log in to unmask]


-----Original Message-----
From: Tom Parkinson [mailto:[log in to unmask]]
Sent: Wednesday, December 31, 2003 10:24 AM
To: [log in to unmask]
Subject: [TN] Epoxy Potting - Leaks


We're a CM and building an assembly using a potted transformer. One of our
steps in the manufacturing process after aqueous washing is to put the
assemblies in a dry heat oven at approximately 180 degrees F for 2 hours to
ensure any water left over from washing is evaporated.
This is the first time we have seen where a potted transformer has leaked
the epoxy filling after being dried, and in some cases, has swollen the
plastic housing that the transformer is encased in.  We double checked the
temp. Is this something anyone else has seen? Should we have a lower
temperature???

Tom Parkinson - Quality System Manager
WinTronics, Inc.

---------------------------------------------------
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
-----------------------------------------------------

---------------------------------------------------
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
-----------------------------------------------------