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Re: Dissolve Xfmr laminations



Original poster: "Richard Williams by way of Terry Fritz <twftesla-at-qwest-dot-net>" <richardwwilliams-at-earthlink-dot-net>

Daniel,
I too got hold of three large transformers (same dimensions but different
windings) and have taken the laminations apart. With E and I together they
measure 6.375 x 5.625. It wasn't as easy with these two as you described
with yours. There was a very thin coating throughout which I have not
removed. I measured the resistance and it's very high, over a couple megohms
depending on the pressure applied to the probes. This coating is very thin
but insulative. I'll take Godfrey's advice and not remove it. It won't add
that much extra width anyway when I reassemble so if I were you I'd think
about not removing the coating unless there's a special reason you really
need to do so.

I'm now waiting for a core to be made so I can wind the coils. Nice having
friends. :)

Rick W.
Salt Lake


----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, January 19, 2002 10:01 PM
Subject: Re: Dissolve Xfmr laminations


> Original poster: "Daniel Hess by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<dhess1-at-us.ibm-dot-com>
>
>
> Rick;
>
> Will do. If I can't find the stuff I may use ordinary shellac. When I was
> in junior high, electric shop, I built a 120-to-14 volt transformer. Had
to
> cut up the laminations from a sheet of ordinary galvanized steel on a foot
> operated shears, built the coil form from heavy fiberboard and wound the
> primary and secondary coils by hand. Put the whole thing together with
> shellac and mounted it on a wood base. What impressed me the most is that
> the sumbitch actually worked although my dad was a little concerned with
> the exposed 110 VAC connections. (hehe, if he only knew of the things to
> come!)
>
> At any rate, here's an update thus far; Of the two transformers, they are
> both identical except one was built years before the other. The newer one
> is coated in the root beer looking stuff (Formvar, we believe) but the
> older one has a gray, enamel looking stuff. Was able to pick up a quart
> each of xylene and MEK today and tried my luck. The xylene was useless but
> the MEK did dissolve the gray, enamel stuff. And rather well, too. Nothing
> fazes the Formvar.
>
> I think it was Godfrey that hit the nail on the head with the butter knife
> suggestion; I used a belt sander to remove the external coating along the
> edges of the core. Didn't take much, just lightly got me down to shiny,
> silver metal. Then using a single edged razor blade I was able to easily
> pry each layer apart. The sealant is so brittle that with a little
pressure
> it 'pops' apart as a bad glue joint. Someone on the list suggested that
the
> laminations were packed so tight that there might not be any sealant
> in-between them but there is (alas!) With the grey stuff I can just soak
> them in a tray of the MEK but the Formvar will have to be individually
> scrubbed with steel wool to clean them up (ugh!) unless I can find a
> solvent which will dissolve this stuff. But that's where I came in.
>
> More to come.
>
> Daniel
>
> To:    tesla-at-pupman-dot-com
> cc:
> Subject:    Re: Dissolve Xfmr laminations
>
>
>
> Original poster: "Richard Williams by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <richardwwilliams-at-earthlink-dot-net>
>
> Daniel,
>
> I quote:
> "I expect to use some sort of varnish when I do the reassembly (Formvar?)"
>
> If you locate the stuff let me know. I've been looking for it for some
time
> now.
>
> As far as the welded bead I have no idea so that will have to come from
> someone more knowledgable on the subject. Sorry.
>
> Rick W
> Salt Lake City
>
>
>