How to melt/remove epoxy?

TORROID

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Jul 23, 1996, 3:00:00 AM7/23/96

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Anyone have any suggestions. I'm looking for something that can easily
strip epoxy potting from a HV X-former that has burned open internally.
This is some *hard* stuff, it's kinda off white in color, I'm assuming
it's epoxy. Melting the plastic case or destroying the wire enamel is
acceptable if necessary, however melting the copper wire before I can
count the windings is not acceptable.

Torroid

Richard K. Downer

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Jul 24, 1996, 3:00:00 AM7/24/96

to TORROID

If all you want to do is count the windings (so you can find a
replacement?) and not actually repair this transformer, then why not
saw it in half? That's probably going to give you the most accurate
winding count you're going to get.
--
Rick Downer
rkd...@ballard.ca.boeing.com

These opinions are not mine, they're Boeing's. Boeing paid me while I
opined them, so Boeing owns them. But Boeing might not agree with them.

Roy McCammon

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Jul 25, 1996, 3:00:00 AM7/25/96

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"Richard K. Downer" <rkd...@ballard.ca.boeing.com> wrote:
>TORROID wrote:
>>
>> Anyone have any suggestions. I'm looking for something that can easily
>> strip epoxy potting from a HV X-former that has burned open internally.
>> This is some *hard* stuff, it's kinda off white in color, I'm assuming
>> it's epoxy. Melting the plastic case or destroying the wire enamel is
>> acceptable if necessary, however melting the copper wire before I can
>> count the windings is not acceptable.

I have done similar things using a hot air gun and a small flat
blade screw driver. The heat softens in potting compound then
I gently scrape it out with the screw driver. Takes about 4
hours to unpot a 2 x 2 x 1/2 inch module.

Reverse engineering the other guys succesful product is one of
the most cost effective ways any engineer can spend his time.

Opinions expressed herein are my own and may not represent those of my employer.

Phil Nash

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Jul 26, 1996, 3:00:00 AM7/26/96

to TORROID

TORROID wrote:
>
> Anyone have any suggestions. I'm looking for something that can easily
> strip epoxy potting from a HV X-former that has burned open internally.
> This is some *hard* stuff, it's kinda off white in color, I'm assuming
> it's epoxy. Melting the plastic case or destroying the wire enamel is
> acceptable if necessary, however melting the copper wire before I can
> count the windings is not acceptable.
>

> Torroid

Torroid,

There is a product called "ATTACK" on the market. I found it at a
jewelery supply outfit. It removes all the epoxies that I have tried it
on so far quite handily.

Good Luck...
Phil

--
See us at http://www.cgntech.com (neat HC11 development accessories)

Calum MacGregor

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Jul 27, 1996, 3:00:00 AM7/27/96

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In article <31F902...@cgntech.com>, Phil Nash <pn...@cgntech.com>
writes

>TORROID wrote:
>>
>> Anyone have any suggestions. I'm looking for something that can easily
>> strip epoxy potting from a HV X-former that has burned open internally.
>> This is some *hard* stuff, it's kinda off white in color, I'm assuming
>> it's epoxy. Melting the plastic case or destroying the wire enamel is
>> acceptable if necessary, however melting the copper wire before I can
>> count the windings is not acceptable.
>>
>

Hi,

I wouldn't really recommend this, but concentrated sulphuric acid will
eat the epoxy and not touch the copper at all. But it's *really* nasty
stuff. Some PCB manufacturers used to use it to remove unwanted epoxy
from multilayer PCB surfaces and multilayer bonding plates back in the
dark ages.
Cheers!

Calum MacGregor
Electroconnect Ltd. 01294 221360 <ca...@econnect.demon.co.uk
Design . Fast turn PCB . Flexi-rigid PCB . SMT Assembly . Laser Stencils

Gabo

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Jul 29, 1996, 3:00:00 AM7/29/96

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In article <4cYemCA3...@econnect.demon.co.uk>, Calum MacGregor
<ca...@econnect.demon.co.uk> wrote:

'
I would recommend going easier than with sulfuric, (you may end up
removing more than epoxy). Try using N-Methylpilorridone, it is an
industrial epoxy remover, and relatively harmless. One possible source for
this and other epoxy removers is Dynaloy. I don't have their phone or
addres handy, but if still interested e-mail me for the info.

I use this stuff daily and it will strip the epoxy of a hi-voltage
transformer in about 30 minutes when heated. Kind of messy, though.

Gabriel
F.A. Engineer
Optek Technology

--
What do you think people have feet for?
To work the gas pedal.
Calvin