MTFCA Forum

So, I am in the process of recharging my magnets with a new coil ring. (previous post). Engine in stand with flywheel and tranny attached, no pan or hogshead. I connected my 3 twelve volt batteries, and tried to zap it, but no spark. I am using the engine block for the ground. I checked for continuity from mag post disk to block with no continuity. I checked the mag post disk itself for continuity on it, with no continuity. There is a thick coating on the mag ring. I think this coating is preventing any transfer of power. Anyone have experience with this issue? I assume I need to remove some of the coating, but don't want to damage anything. I used a nail in the cable that goes to the mag post, with no luck, I guess I didn't penetrate the coating. What should I do next? Thanks Tommy.

Clean a place on iron of the mag ring and see if you have continuity through the coils. If it’s good there then all you have to do is pull the transmission assembly, pull the mag ring and clean the mounting surface of the ring and block. You may need to re shim the ring, as the lacquer coating can be pretty thick.

I’m not exactly sure what you are saying or asking but your mag coil rebuilder should not have coated (encased) the entire magneto mounting ring and coils in whatever coating he used. I assume “Glyptal” as that is the only insulator coating that I know of, that should be used on electrical windings. If the entire assembly has been encased in “Glyptal”, I wonder why he did that. You should, at least, remove the coating on the back side of the four hole mounting bracket, the flat metal coil faces and the button by scraping off with a razor blade as electrical current will not pass through “Glyptal”. Jim Patrick

If it is coated over the bobbins on the ring it could be thick enough to change the gap. Once you clean it off you should recheck the gap.

The method my electric motor re-winder uses is o dip whatever component he wishes to insulate, to make sure it is totally insulated. This means that a mag coil ring does need the faces on the ring, the mounting flange and the contact post cleaned off after the dipping. The insulation/dip material is an aid to "gluing" the coils to the plate.

Allan from down under.

When I received the mag ring some of the ribbons had a slight twist to them. I called the company, and they said to apply some power to the ring and check each post with a compass, and see if it flips at each post which it did. I can't remember where I connected the power source to, but I think it was at the edge of the mag post disk, and not on the top of it. The compass did swing at each post, so I think the continuity through the coils is ok. If I scrape the coating off the mag post disk, and then get continuity, would I still have to pull the mag ring off and clean the lugs? Thanks for the inputs. Tommy

Here is a picture of the mag post area. The copper colored area is completely covered with a coating.

The new mag ring..

The 2ed photo up from the bottom, you are reading the magnets not the coil ring. The contact point also needs to be cleaned if you haven't. Once the flywheel/magnets/transmission are removed, power is run thru the base of the coil ring and the contact at the top, then each of the coils are checked with a compass.
Unless there is a dead short, the only spark you should/might see is when the probe you are using makes contact. If that 2ed up photo is current, I don's see any signs of the covering being disturbed like I would expect if you were doing a recharge except for that one small spot. As said above, the varnish is not allowing current to flow and is acting like an barrier. Which could have been the problem to start with.

Mark Gregush wrote: ↑

Tue Feb 09, 2021 11:16 am

The 2ed photo up from the bottom, you are reading the magnets not the coil ring. The contact point also needs to be cleaned if you haven't. Once the flywheel/magnets/transmission are removed, power is run thru the base of the coil ring and the contact at the top, then each of the coils are checked with a compass.
Unless there is a dead short, the only spark you should/might see is when the probe you are using makes contact. If that 2ed up photo is current, I don's see any signs of the covering being disturbed like I would expect if you were doing a recharge except for that one small spot. As said above, the varnish is not allowing current to flow and is acting like an barrier. Which could have been the problem to start with.

Thanks..Yes, in that photo I am checking the magnets. The other test I did prior to installation. You are correct the coating is still on the mag disk. I will remove a small portion and recheck.

Steve Jelf wrote: ↑

Tue Feb 09, 2021 11:24 am

Looks like the bolt holes were masked and are bare metal. Good enough. Clean the coating off the solder button and check continuity between there and the bolt holes. If there's coating on the backside of the bolt holes you can wire brush that off just to be sure of a good ground. It appears that the poles were masked, but if they weren't and there's coating on their faces I would remove that too.

Thanks..I will clean the coating off today and retest.

Clean off the faces of the individual coil windings, the contact button on top of the ring and the bolt holes of the mag ring. All of theses areas have to be clean for the ring to work like it should.
The ring rebuilder did a pretty good job of coating the ring. That’s a good thing to do I think. I wouldn’t mind cleaning off the necessary contact places.
To me the good coating makes for a short proof ring.

John kuehn wrote: ↑

Tue Feb 09, 2021 12:16 pm

Clean off the faces of the individual coil windings, the contact button on top of the ring and the bolt holes of the mag ring. All of theses areas have to be clean for the ring to work like it should.
The ring rebuilder did a pretty good job of coating the ring. That’s a good thing to do I think. I wouldn’t mind cleaning off the necessary contact places.
To me the good coating makes for a short proof ring.

I just got off the phone with the supplier. He said the mounting points, and the coil poles are cleaned off. The mag post area will be penetrated by the mag post point when it is installed. Unfortunately, I need it cleaned off sooner. I am going to clean a small area off today, and try my magnet recharge again..Thanks

If there is Glyptal coating the backside of the four hole mounting bracket, I would take a razor blade and scrape off the coating from the back of the mag coil mounting where it mates up to the block to ensure a tight flush fit. The coating is softer than the steel and in the hot environment of a running engine a thick coating of Glyptal between the mating surfaces, under pressure from the four tightened bolts could soften and cause a, once tight fit, to become loose, disrupting your spacer shims, causing the mag ring to make contact with the magnets. Something that must be avoided at all costs. Jim Patrick

Well, I cleaned the coating off the mag post disc, and all went well. Thanks for all the help..Tommy

How are you connecting the batteries? Series? Should have 36 volts. Are you sure the batteries are good? I use a DC welder when I do this. Dan

im with you on the welder dan works great once you understand polarity. philip

Dan Hatch wrote: ↑

Wed Feb 10, 2021 2:30 pm

How are you connecting the batteries? Series? Should have 36 volts. Are you sure the batteries are good? I use a DC welder when I do this. Dan

Yes, connected in series..I did check them individually and connected. Ended up with 42 volts at the end. I always have good batteries on hand..Thanks..I have a MIG welder, but that is it.