Armature damage from alcohol?

[mmagliaro]

In the course of reading a nerdy article on the use of Faulhaber and Maxon motors for space applications...
http://adsabs.harvard.edu/full/2003ESASP.524..271L

I noted something on page 2 of the article.  They fully disassembled these motors and cleaned out all the conventional lubricant, replacing it with a variety of dry lubricants so it would function in extremely cold temperatures.  But the thing that caught my eye was that they noted that they could not clean the armatures in a Faulhaber motor with isopropyl alcohol because the alcohol dissolved the insulating lacquer on the armature windings!

I never knew that would happen.   I have never taken apart a Faulhaber motor with the intent of reassembling it and expecting it to work, so I have never tried to clean the insides of one.  But I certainly have cleaned conventional motor commutators with alcohol.   

Now I'm wondering if the armature lacquer would be destroyed on those too, if I got alcohol on the windings.  Has anybody seen this happen?  Ever ruin a motor by brushing alcohol over the armature?

[C855B]

Brushing alone with an alcohol-moistened toothbrush, no, but soaking then brushing, yeah, I killed an HO motor this way back when I was a teen. I fully intended to rewind it after that particular bout of stupidity... and the bare armature is still rattling around in a junkbox, half a century later.

[mmagliaro]

Brushing alone with an alcohol-moistened toothbrush, no, but soaking then brushing, yeah, I killed an HO motor this way back when I was a teen. I fully intended to rewind it after that particular bout of stupidity... and the bare armature is still rattling around in a junkbox, half a century later.

Not stupidity!  A learning experience!  And now look, 50 years later, you have been able to pass that knowledge on to me.
THANKS!  (not joking)

[peteski]

I have never  seen alcohol affect the enamel insulation on magnet wire. That stuff is quite resistant to most solvents.  Maybe older (or cheaper made) enameled wire used enamel which was affected by solvents?  Although I have never let anything with magnet wire soaked in alcohol for prolonged periods.  I use Naphtha for cleaning motors.  I suppose one could test this easily by using alcohol on a piece of magnet wire and see if it can be stripped to bare copper.

As far as the winding "basket" of a coreless motor goes, I  suspect that it is the adhesive/sealant  (not the magnet wire's tough enamel insulation) which holds the shape of the basket that can be affected by solvents.  I never had a need to clean one of those.

[u18b]

I have this feeling that Max has some experiments percolating in his mind....... and which motors he can risk killing.   

[CRL]

Considering some lacquers are made from shellac and alcohol, this isn’t surprising.

[Doug G.]

The term "lacquer" is sometimes used very loosely. It can be formulated using various materials, some affected by alcohol and some not.

Doug

[peteski]

The term "lacquer" is sometimes used very loosely. It can be formulated using various materials, some affected by alcohol and some not.

Doug

Actually magnet wire is "enameled" not "lacquered". At least that is the term I am used to.

From https://en.wikipedia.org/wiki/Magnet_wire

Magnet wire or enameled wire is a copper or aluminium wire coated with a very thin layer of insulation. It is used in the construction of transformers, inductors, motors, speakers, hard disk head actuators, electromagnets, and other applications that require tight coils of insulated wire.

The wire itself is most often fully annealed, electrolytically refined copper. Aluminium magnet wire is sometimes used for large transformers and motors. The insulation is typically made of tough polymer film materials rather than enamel, as the name might suggest.

[narrowminded]

From some wood working and antique furniture repair the rule was always, alcohol is the solvent for shellac and will not effect lacquer.  Try alcohol first.  If that doesn't do it, go to lacquer thinner.  You could reflow either one to repair a damaged piece without a total stripping.  It would dissolve the coating and reflow it for a perfect repair.  It works.   That would suggest to me that some of those alcohol effected "enamels" were actually shellac.

Edit: Copied from this wikipedia link: https://en.wikipedia.org/wiki/Shellac

"Shellac was used for fixing inductor, motor, generator and transformer windings. It was applied directly to single-layer windings in an alcohol solution. For multi-layer windings, the whole coil was submerged in shellac solution, then drained and placed in a warm place to allow the alcohol to evaporate. The shellac locked the wire turns in place, provided extra insulation, prevented movement and vibration and reduced buzz and hum. In motors and generators it also helps transfer force generated by magnetic attraction and repulsion from the windings to the rotor or armature. In more recent times, synthetic resins, such as glyptol, (Glyptal), have been substituted for the shellac."

[peteski]

From some wood working and antique furniture repair the rule was always, alcohol is the solvent for shellac and will not effect lacquer.  Try alcohol first.  If that doesn't do it, go to lacquer thinner.  You could reflow either one to repair a damaged piece without a total stripping.  It would dissolve the coating and reflow it for a perfect repair.  It works.   That would suggest to me that some of those alcohol effected "enamels" were actually shellac.

Mark, the original question was about *NOT* damaging any windings in the motor's armature.

And you are correct that many electrical devices  (like motors or transformers) which have windings use some sort of shellac or similar produce to seal the windings and laminated metal cores.  But the magnet wire used in the windings already has the "enamel" insulation on it.

[Doug G.]

Actually magnet wire is "enameled" not "lacquered". At least that is the term I am used to.

From https://en.wikipedia.org/wiki/Magnet_wire

Magnet wire or enameled wire is a copper or aluminium wire coated with a very thin layer of insulation. It is used in the construction of transformers, inductors, motors, speakers, hard disk head actuators, electromagnets, and other applications that require tight coils of insulated wire.

The wire itself is most often fully annealed, electrolytically refined copper. Aluminium magnet wire is sometimes used for large transformers and motors. The insulation is typically made of tough polymer film materials rather than enamel, as the name might suggest.

Yes, I realize most magnet wire is enameled or is coated with a polymer, which is tougher, I have worked with it a lot, but Max's original post stated the maker said theirs was lacquer. Hence my referencing it as such.

Doug

[MK]

How about using plastic safe clearners like DeOxit Fader Lube?  Probably won't be as clean as straight alcohol but won't dissolve anything questionable.

[Doug G.]

Actually, it may clean better. Alcohol isn't really the solvent most people think it is, especially for petroleum based material. For instance, with the typical use of 91% alcohol to clean wheels by soaking a paper towel with it and running wheels across the towel, you will find that Goo Gone or other petroleum distillate type cleaner (and it IS the petroleum distillate that does the cleaning, not the orange) will work much better and with much less effort.

Doug

[peteski]

Actually, it may clean better. Alcohol isn't really the solvent most people think it is, especially for petroleum based material.

That is why I said "I use Naphtha for cleaning motors." in reply #3 of this thread.  It is inexpensive (I get VM&P Naphtha in a gallon container in a hardware store) and it is excellent for dissolving petroleum-based lubricants. Leaves no residue either.

I do use alcohol for other tasks. I buy the 99% Isporopanol, again in a hardware store, in a gallon size container.

[wm3798]

As a neophyte model railroader back in the 70s, I'm pretty sure I murdered my Trix U30CG in this manner.  Hellbent to get it to run smoothly, I cleaned the wheels with Isopropyl, then decided that swabbing the commutator with the stuff would do just the trick.  It ran about two feet then the motor flamed out.  Being a nitwit, I decided that More was Better, so I did it again, and the thing didn't even budge.

Reading this thread makes me realize I've probably committed Lococide more times than I care to admit, having never bothered to understand the chemistry of the situation.

Thanks for immersing me in a sea of guilt, with images of numerous favorite engines... teats up and X's over their eyes... now stuck in my head forever.

Lee