Re: Potato Chips (fwd)
---------- Forwarded message ----------
Date: Mon, 27 Apr 1998 08:48:38 -0500
From: David Huffman <huffman-at-fnal.gov>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Potato Chips (fwd)
One thing to note here is the purpose of the laminations. Laminations help
prevent eddy currents if each laminate is electrically insulated from the
next. Each laminate is varnished before it is used. If you remove the
coating and assemble the core, it will get hot from the eddy currents.
Sometimes just splitting the laminations apart pulls to coating off and will
cause hot spots.
Just my 2 cents worth.
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Sunday, April 26, 1998 11:58 PM
Subject: Potato Chips (fwd)
>---------- Forwarded message ----------
>Date: Sun, 26 Apr 1998 05:08:25 -0700 (PDT)
>From: gweaver <gweaver-at-earthlink-dot-net>
>Subject: Potato Chips
>The laminations on one of my unpotted neons is out of square. The thing is
>twisted looking and I don't like the way it looks so I took it all apart.
>The laminations were stuck together with something like varnish or
>polyurethane. I decided to sand blast the laminations to remove the
>varnish. When the sand hit one side of the lamination it instantly curled
>up like a potato chip. The varnish came right off. I turned the lamination
>over and sand blasted the other side and the metal instantly curled up in
>the other direction. I tried to straighten it out by sand blasting back
>forth a little on each side but it won't straight up. I tired hammering it,
>but its still not flat. I tried 3 more laminations and they did the same
>thing. There must be some type of stresses in the metal that cause this to
>happen. WARNING, don't sand blast transformer laminations. Acetone takes
>the glue stuff off of the lamination with no trouble at all. Just let the
>lamination soak about 15 minutes. You don't even have to wipe them clean
>with a rag.