material inside tranny bell covers?

[Randall]

I recently took the bell covers off two transformers for cleaning and restoration. Both had an insulator wrapped inside the covers and folded around the windings. I set them aside, and I don't know how it happened, but one went missing. So, my question is, what material are they made from and what is their function. They actually seem like card stock, as I can easily tear them. But, just old card stock, or something more? If I were to fashion a replacement, what should I make it of?

[Enzo]

It looks like that black or dark gray cardboard like inside many candy bar wrappers, yes? it is called "fish paper". It is a card stock made for the purpose.

I often use Scotch 27 glass tape in such situations.

[nosaj]

I recently took the bell covers off two transformers for cleaning and restoration. Both had an insulator wrapped inside the covers and folded around the windings. I set them aside, and I don't know how it happened, but one went missing. So, my question is, what material are they made from and what is their function. They actually seem like card stock, as I can easily tear them. But, just old card stock, or something more? If I were to fashion a replacement, what should I make it of?

tubesandmore sells fishpaper. Not very expensive..

nosaj

[Enzo]

Cool, I didn't know that.

Oh sure, 10x24" sheet for $5 and change, not bad.

[nosaj]

Cool, I didn't know that.

Oh sure, 10x24" sheet for $5 and change, not bad.

That's what this forum is all about . The collective knowledge around here rocks and eventually your going to get me to try stuff before asking. I feel like a really slow learner sometimes.

nosaj

[Randall]

I only need a small piece. Anyone have a 3" x 5" piece they'd part with?

[J M Fahey]

It´s treated insulating paper, same as used to build and wrap transfomer bobbins. "Pressphan" .
Of course any transformer winder has lots of odds and ends lying around

You *might* use plain cardboard or plastic sheet but cardboard could take humidity (treated paper is lightly impregnated in phenolic varnish and plain plastic may melt and contacts short) so a household item which works properly is that thick and translucent "baking paper" , you might use a double thickness of it to play it safe.
Don´t know the common English name, we literally call it "buttered paper" (papel manteca) and you can get it at local Supermarket (or raiding Wifey´s cooking stuff )



Similar to thick tracing paper or "vellum", it both stands humidity and temperature.

[Enzo]

We call it waxed paper.

[nosaj]

We call it waxed paper.

Parchement paper is another type. But I would think if Randall is in it for the long haul Fish paper would be the way to go because of the dielectric propertieshttps://en.wikipedia.org/wiki/Fishpaper
At under $10 shipped i sure you could use the rest on repairs somewhere else.
Sometimes ordering just a little more of something gives you a little stock down the road reducing wait times for customers.

nosaj

Dielctric properties of waxed paper
https://hypertextbook.com/facts/2007...ulyukova.shtml

[Randall]

"Sometimes ordering just a little more of something gives you a little stock down the road reducing wait times for customers."

And sometimes all you want and need is a little piece of something just to get you by.

[Justin Thomas]

You could just charge exorbitant fees to people later on who need "just a little bit..."

I'd honestly be willing to try Juan's way, if he's willing to fess up and say he's done it before. Or, just "wax" (treat) some cardstock. Or call around to some craft stores and hobby shopss, if you have any in your area?

Suddenly, that box labelled "bits of crap I pulled from dead trannies" seems a good idea...

Justin

[g1]

And sometimes all you want and need is a little piece of something just to get you by.

That's what your scrap/odds & ends pile is for. Saved any bad x-formers?
Sometimes I use my local thrift shop as my scrap pile.

[nosaj]

You could just charge exorbitant fees to people later on who need "just a little bit..."

I'd honestly be willing to try Juan's way, if he's willing to fess up and say he's done it before. Or, just "wax" (treat) some cardstock. Or call around to some craft stores and hobby shopss, if you have any in your area?

Suddenly, that box labelled "bits of crap I pulled from dead trannies" seems a good idea...

Justin

The wiki also said it is found in stoves.

nosaj

[Randall]

I'm not going to buy a big chunk of this stuff since for the first time in 30+ years I have ever needed a little piece, regardless of the price. I'll try the wax paper I guess.

[Enzo]

If I buy a piece the size of a place mat for $5 but only need a 3x5 hunk, I charge the customer $7 for insulating materials. Now my $5 is free to me, and I can always use it. I can cut a piece for under a circuit board, or as a light mask for a photo cell, or as most anything. How about that custom fit piece of plastic in the bottom of a Boss pedal? I often needed a small piece of insulating material. I used to save those fake credit cards that came in the mail as credit card offers "your name here" they say. I use them as insulators. I sometimes cut a piece out of a milk jug. Point is there are more times than you might think when I need some insulation. I don't have to use fish paper for much of it, like a 9v battery circuit, but if I had the stuf it would be handy and sturdy as a choice.

Bottom line is customer paid for it.