John Deats Posted November 21, 2022 Share Posted November 21, 2022 When it comes to insulating windings, some people say that spray varnish is nothing more than paint. Many stators I have seen have cloth electrical tape used as an insulator. I have searched old and new forums for this one question, but could not find the answer, much less the question. When it comes to insulating stator windings, has anyone ever used liquid tape to insulate anything ? I haven't done any fans this way, but can it work ? It sounds practical, yet possibly I'll advised. Quote Link to comment Share on other sites More sharing options...
Jim Kovar Posted November 21, 2022 Share Posted November 21, 2022 Quote Link to comment Share on other sites More sharing options...
Mark Olson Posted November 21, 2022 Share Posted November 21, 2022 Please don't use "liquid tape" on motor or speed coil windings☹️ 2 Quote Link to comment Share on other sites More sharing options...
John Deats Posted November 21, 2022 Author Share Posted November 21, 2022 So if using liquid tape, your chances of burning out the stator is very possible, and dangerous ? Quote Link to comment Share on other sites More sharing options...
Mark Olson Posted November 21, 2022 Share Posted November 21, 2022 (edited) 26 minutes ago, John Deats said: So if using liquid tape, your chances of burning out the stator is very possible, and dangerous ? The "liquid tape" itself will not burn up the windings. If the windings are shorted, nothing applied to them will fix that. If the liquid tape were applied thick enough, it could cause the windings to overheat, and depending on the brand of liquid tape, the material itself may not withstand the heat of the motor. The liquid tape dries into a rubber like compound that must be cut away. That does not lend itself to ease of rewinding in the event that it becomes necessary. The motor would have to be "burned out" in a high temperature oven (or a barbeque pit). The "sprayon" brand varnish is an excellent "fixative" for both old windings in good condition, and new windings. As stated by Mr. Campbell, the spray varnish will penetrate deep into the windings. Spray motor varnish is not "just paint", it has a high dielectric strength measured in volts per mil. Paint is not rated for voltage, and some conduct electricity! There are some "dipping varnishes" on the market, but they are expensive (Glyptal). Of course, the big motor shops use V.P.I., as stated by Mr. Kovar, and it does produce superior results, but fan and washing machine motors do not need that. The shops that use V.P.I. also have "burn out" ovens. Edited November 21, 2022 by Mark Olson spelling error 1 Quote Link to comment Share on other sites More sharing options...
John Deats Posted November 21, 2022 Author Share Posted November 21, 2022 Mark, thanks for your input. When I saw electrical tape being used, i had to ask about the liquid. Cloth can breath, rubber coating definitely not. I'll keep the liquid for repairing bakelite plugs. Quote Link to comment Share on other sites More sharing options...
Ron May Posted November 22, 2022 Share Posted November 22, 2022 2 hours ago, Chris Campbell said: Always wanted to do this for chokes, but $65 quart for varnish to submerge is insane. I work at a large electric motor repair shop. I'm fortunate to have full access to the VPI tank, the regular dip tank and a burnout and a few baking ovens. I think the VPI is overkill for the fan motors. But I have dipped and baked my fan projects. When working in my shop at home, I have some varnish I "borrowed" from work and a toaster oven, perfect for dipping and baking choke coils and stators. 1 Quote Link to comment Share on other sites More sharing options...
John Deats Posted November 22, 2022 Author Share Posted November 22, 2022 Ron, most of the fans I work on have descent stators, except for century. I give them a good cleaning with electrical spray cleaner, let them dry, then spray varnish. Your process sounds pretty thorough and great. Chris, I like your idea as well, but I think I will stay with the $15.00 spray can varnish. I stared at that bottle of liquid tape and thought if it might be possible. Thanks to all of you for bringing me back on point. Jim, remember to play the shallows. Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 22, 2022 Share Posted November 22, 2022 (edited) When stator magnet wire winding insulation get bad throughout, all the kings' horses, and all the kings' men, won't be able to save those windings again. the more the windings internally start to short, the higher the ohms and the hotter she runs. Motor shops rewind with new insulated magnet wire and dip the windings so it penetrates deep. Spray varnish will soak in so far, and it definitely makes the stator/winding cosmetically look new again. Edited November 22, 2022 by Russ Huber Quote Link to comment Share on other sites More sharing options...
Ron May Posted November 22, 2022 Share Posted November 22, 2022 4 minutes ago, Chris Campbell said: Ron, Would a varnish vacuumed coil have any flexibility? Could see flexibility being irrelevant on a stator, but as you know speed choke coils sometimes needs that flexibility when stacking the laminates Once they're baked there isn't any flexibility. I'll usually test fit before dipping and leave a little extra room so the coil can be taped up after baking. 2 Quote Link to comment Share on other sites More sharing options...
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