Well, you *could* always bring it up to 800°F, that's sure to char everything inside the transformer... 
Including the enamel on the wire, leaving it useless.
(But if you don't give a damn about it - or the smell!
, then I think this would actually work.)
Laminations are usually seperated very tediously with a knife and bit of persuasion (small hammer to break the lam. off its varnish).
Tim
Including the enamel on the wire, leaving it useless.
(But if you don't give a damn about it - or the smell!
, then I think this would actually work.)Laminations are usually seperated very tediously with a knife and bit of persuasion (small hammer to break the lam. off its varnish).
Tim
You don't want to burn the insulating coating off the laminations otherwise they will behave as one big metal block instead of separate slices, and the eddy current losses will be enormous. Very hot very quick.Sch3mat1c said:Well, you *could* always bring it up to 800°F, that's sure to char everything inside the transformer...
hello,
im assuming its just an average, varnish impregnated power transformer type of thing. basically, what i have found to work best is to take a file, and to square off all the edges of a slotted screwdriver, to make it pretty much as good and sharp as a new one. take a razor blade and go around the edges of the top lamination on either side of the transformer (go for the one that seems easiest to get at). try to break the lamination off as much as possible. next, put the transformer so the bottom of the lamination is hanging off the edge of a desk, and use the screwdriver and a hammer to tap out the first lamination. this process is pretty tough to put in writing, but basically you are getting the first one out at all costs, because once its out, the other ones come out with no problem. dont worry about messing it up, because usually it is very difficult or impossible to get them all back in anyways. i usually have a few left over and it doenst harm much. good luck.
-chris
im assuming its just an average, varnish impregnated power transformer type of thing. basically, what i have found to work best is to take a file, and to square off all the edges of a slotted screwdriver, to make it pretty much as good and sharp as a new one. take a razor blade and go around the edges of the top lamination on either side of the transformer (go for the one that seems easiest to get at). try to break the lamination off as much as possible. next, put the transformer so the bottom of the lamination is hanging off the edge of a desk, and use the screwdriver and a hammer to tap out the first lamination. this process is pretty tough to put in writing, but basically you are getting the first one out at all costs, because once its out, the other ones come out with no problem. dont worry about messing it up, because usually it is very difficult or impossible to get them all back in anyways. i usually have a few left over and it doenst harm much. good luck.
-chris
Thanks for replies!!
It's standard EI power supply transformer made of laminated metal sheets - I think I will try do as proposed: using knife, screwdriver and hammer remove first lamination and then if it's easier to remove the rest as gently as possible - I'm looking for that kind of lamination in the shops for substitute. I tried yesterday removing the first lamination and the are very stiff and I found it very difficult to separate them....
Thanks again!
Greets,
It's standard EI power supply transformer made of laminated metal sheets - I think I will try do as proposed: using knife, screwdriver and hammer remove first lamination and then if it's easier to remove the rest as gently as possible - I'm looking for that kind of lamination in the shops for substitute. I tried yesterday removing the first lamination and the are very stiff and I found it very difficult to separate them....
Thanks again!
Greets,
It would be primarily the oxide because the tranny will work without any varnish. I heard once that when an electric motor has really had the gizzard burnt out of it, it affects this oxide stuff and when rewound is not quite as good as it used to be. Mild burnouts are ok though.Sch3mat1c said:
Re: Nail polish remover even.
Dunno about gas... ...gotta pick your solvent for your purpose. The acetone will soften the surface varnish immediatley... ...it'll be tacky as soon as you get it wet. Do the same check with the gas. It takes time to soak into the little cracks and crevices.
Nail polish remover used to be acetone, but I think the stuff used now is a non-acetone chemical. (Wife just verified some of it is not acetone) You can buy actone in most painting supply stores... ...I even buy it at wal-mart. It's not really all that expensive.
I just store the transformers in the acetone until I'm ready to unwind them. It also helps to use a pair of chemical resistant gloves when unwinding the transformer... ...as soon as the acteone dries, the varnish seems to set up again Gets all over your fingers otherwise...
-Dan
(Foget the pic, I can't get it to post!!!!)
Circlotron said:
Dunno about gas... ...gotta pick your solvent for your purpose. The acetone will soften the surface varnish immediatley... ...it'll be tacky as soon as you get it wet. Do the same check with the gas. It takes time to soak into the little cracks and crevices.
Nail polish remover used to be acetone, but I think the stuff used now is a non-acetone chemical. (Wife just verified some of it is not acetone) You can buy actone in most painting supply stores... ...I even buy it at wal-mart. It's not really all that expensive.
I just store the transformers in the acetone until I'm ready to unwind them. It also helps to use a pair of chemical resistant gloves when unwinding the transformer... ...as soon as the acteone dries, the varnish seems to set up again
Gets all over your fingers otherwise...-Dan
(Foget the pic, I can't get it to post!!!!)
When new EI lamination has a thin oxide layer left by the oil used during stamping (cutting) with the die. This oxide forms after they heat the cut laminations in an oven.
In my experiance the best way to undoo a transformer is by heating it to burn all but the metal. Heating lamination wont degrade it, in the contrary it may betterd it and you will still have an oxide layer. It wont act a a solid chunk of iron.
When putting back the transformer you must varnish it again, with thin electrical varnish this will penetrate beteen the lamination. After this proccess you will find the efficiency of the trany will be better than before (to various degrees).
What degrades lamination is the mechanical work over it like hammering or tweesting.
Never tested using solvent to undoo a trany so can't comment.
In my experiance the best way to undoo a transformer is by heating it to burn all but the metal. Heating lamination wont degrade it, in the contrary it may betterd it and you will still have an oxide layer. It wont act a a solid chunk of iron.
When putting back the transformer you must varnish it again, with thin electrical varnish this will penetrate beteen the lamination. After this proccess you will find the efficiency of the trany will be better than before (to various degrees).
What degrades lamination is the mechanical work over it like hammering or tweesting.
Never tested using solvent to undoo a trany so can't comment.
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