The Ford Barn

Sparky · 11-24-2015, 09:41 AM

I have an old generator I'd like to refurbish. It needs a thorough cleaning and fresh paint, a new front bearing, one of the brush holder posts is loose, and the cloth wire insulation is flaking off, but it does spin freely. I didn't want to try testing it on my car because I was afraid it would self-destruct. So on my workbench, I connected a voltmeter to it and was able to spin it up with a drill as I held it with my hand. The voltage started climbing and when it reached 1-2 volts I could feel it trying to twist from the field starting to build up. Based on this, can I assume it is working OK?

JohnLaVoy · 11-24-2015, 09:43 AM

A simple test is to hook 6 volts to it and see if it "motors" spins on its own. If it does then your fields and armature are sound, if it doesn't then you have a connection or electrical problem.

Tom Wesenberg · 11-24-2015, 10:23 AM

Your generator is probably good. They will start charging the battery when they spin about 750 generator RPM, which is 500 engine RPM.

When the field windings don't work the generator will only put out about 1/2 volt from the residual magnetism.

Liquid tape works great for small amounts of the cloth insulation flaking off.

Sparky · 11-24-2015, 05:31 PM

Ok, thanks. I'll check into liquid tape.

TinCup · 11-24-2015, 06:52 PM

Used liquid tape just this week to touch up insulation on a generator that was given to me. Great stuff for just this kind of fix.

Henry's Lady's Man · 11-29-2015, 01:12 AM

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I just used a compressor to blow off all the black dust from my generator's field coils, and noticed a flap of cloth that is loose. I don't want to "brush" the field coils, fearing I'll remove more cloth insulation. will "liquid tape" seal it up good without a super clean surface?

Tom Wesenberg · 11-29-2015, 02:37 AM

Quote:

Originally Posted by Henry's Lady's Man

I just used a compressor to blow off all the black dust from my generator's field coils, and noticed a flap of cloth that is loose. I don't want to "brush" the field coils, fearing I'll remove more cloth insulation. will "liquid tape" seal it up good without a super clean surface?

Yes, brush on the liquid tape and the wrap should stay in place. I've done the same thing a few times.

11-24-2015, 09:41 AM	#1
Sparky Senior Member Join Date: May 2010 Location: Rhode Island Posts: 649	quick generator bench check I have an old generator I'd like to refurbish. It needs a thorough cleaning and fresh paint, a new front bearing, one of the brush holder posts is loose, and the cloth wire insulation is flaking off, but it does spin freely. I didn't want to try testing it on my car because I was afraid it would self-destruct. So on my workbench, I connected a voltmeter to it and was able to spin it up with a drill as I held it with my hand. The voltage started climbing and when it reached 1-2 volts I could feel it trying to twist from the field starting to build up. Based on this, can I assume it is working OK?

11-24-2015, 09:43 AM	#2
JohnLaVoy Senior Member Join Date: Jun 2014 Location: Rocklin, CA Posts: 779	Re: quick generator bench check A simple test is to hook 6 volts to it and see if it "motors" spins on its own. If it does then your fields and armature are sound, if it doesn't then you have a connection or electrical problem.

11-24-2015, 10:23 AM	#3
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: quick generator bench check Your generator is probably good. They will start charging the battery when they spin about 750 generator RPM, which is 500 engine RPM. When the field windings don't work the generator will only put out about 1/2 volt from the residual magnetism. Liquid tape works great for small amounts of the cloth insulation flaking off.

11-24-2015, 05:31 PM	#4
Sparky Senior Member Join Date: May 2010 Location: Rhode Island Posts: 649	Re: quick generator bench check Ok, thanks. I'll check into liquid tape.

11-24-2015, 06:52 PM	#5
TinCup Senior Member Join Date: May 2010 Location: OKC / Tonkawa, Ok. Posts: 1,977	Re: quick generator bench check Used liquid tape just this week to touch up insulation on a generator that was given to me. Great stuff for just this kind of fix. __________________ Oklahoma City Model A Restorers Group.

11-29-2015, 01:12 AM	#6
Henry's Lady's Man Senior Member Join Date: Apr 2015 Location: Albuquerque, NM Posts: 441	Re: quick generator bench check Sponsored Links (Register now to hide all advertisements) I just used a compressor to blow off all the black dust from my generator's field coils, and noticed a flap of cloth that is loose. I don't want to "brush" the field coils, fearing I'll remove more cloth insulation. will "liquid tape" seal it up good without a super clean surface? __________________ ... prosperity is not the product of charity but of industry - HENRY FORD