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Registered Member #3888
Joined: Sun May 15 2011, 09:50PM
Location: Erie, PA
Posts: 649
No chemistry posts in a week? fine, i've got questions then.
i have several dc flybacks that i've destroyed while trying to get the cores out, does anyone know of a solvent for that white epoxy stuff so that i could salvage the HV diodes/capacitors out of their carcasses?
i disassembled a MOT and have two nice coils of wire from it. the primary wire has been very useful for winding toroids and flyback primaries using leather gloves to flake away the epoxy. However, the secondary is very difficult to work with because of the epoxy slivers of death i get whenever handling it. Does anyone know of a solvent for the epoxy/lacquer/varnish used in MOTs that won't damage the enamel on the magnet wire?
and finally, how can i remove tar residue from a large ballast i ripped apart?
Registered Member #3637
Joined: Fri Jan 21 2011, 11:07PM
Location: Buffalo, NY
Posts: 1068
The problem is the epoxy that's inside of a flyback is incredibly durable. Whatever solvent you'd use would destroy the diodes and capacitors inside of them along with the epoxy, as far as I know.
Registered Member #3888
Joined: Sun May 15 2011, 09:50PM
Location: Erie, PA
Posts: 649
The mot primary wire i have is definitely copper. it must be from an older style oven. I have access to chemicals from two different universities, so i doubt i'l have to buy any.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
I dont think butanone/MEK would do much though, maybe im wrong though.
"Sodium Methoxide in solution of 18-crown-6 ether.", or so ive been told (supposedly) and try not to die.
I must agree with those who say your better off buying new caps and diodes....anything harsh enough to remove epoxy would also remove the diodes and caps form existence.
Registered Member #2261
Joined: Mon Aug 03 2009, 01:19AM
Location: London, UK
Posts: 581
You can get some potted modules apart by heating them in an over to soften the potting compound. In my experience the heat also slowly hardens the compound further, so don't heat for longer than necessary. There might be health consequences tp heating chemicals in a food oven. I try to minimise these by running the oven at maximum heat for an hour after use. Apart from that second head growing out of my stomach, I seem to be ok...
Registered Member #235
Joined: Wed Feb 22 2006, 04:59PM
Location:
Posts: 80
I ended up using a band-saw to cut through the windings next to the core. If you are reasonably careful you will have have a small layer of epoxy on the core that can then be peeled away.
Registered Member #187
Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140
I tried to "unpot" a large-ish flyback using hot N-Methylpyrrolidone about 6 or 7 years ago. I kept it in an oven in the lab at work for at least a week, and the epoxy swelled up and turned to a sort of gelatin. Even in this state I couldn't free the wound core without damaging it. It was a mess.
It seems we would pretty much have to contact a manufacturer (China most likely) and buy a bunch of wound cores before they get potted (wouldn't that be nice!)
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