MTFCA Forum

Over the years from spare parts received along with Model T purchases I have acquired approx. 30 sets of coil points I assume are used as they have minor surface rust and are not in retail packaging. With a micrometer to measure is there a minimum thickness of the points where they are no longer usable?

I do not know whether to throw them out or give to someone new to the hobby or a tiny bit short of money at the present time. I realize these are consumable parts but hate to get rid of something that might be usable to someone. I will never use this many in 5 lifetimes if they measure good. Thanks….

Used points can often be refurbished with an oilstone or a small, high quality file. There are a number of problems they can develop besides the condition of the actual contact points, but a great many used points sets can be made to work well by dressing the contact points. As far as I know, if there is enough of the platinum contacts left to allow dressing the contact faces smooth and leave about 1/32" or more of material, the points will work satisfactorily if the other parts of the set are in good condition. Some variation in spring tension, alignment, etc can be accommodated with careful adjustment and the right test equipment. I wouldn't throw them away.

When the contacts are pitted, worn or there is too much corrosion between the cushion and bridge, or the cushion no longer moves, or the points have been filed too often or not straight across. Toss them. Ya, I have a box full of them that I am hording!
If they just have a little rust and would clean up, that's different. Sure, they are consumable, but 4 sets can add up real fast.

When I inherited my Grandfathers 24 Coupe that I have over 60 years ago boxes of used parts came along with it. Among them was boxes of coils and a smaller box of points. He saved most of what he thought were good used parts.
Most of the points weren’t worn very much if at all. I still have some of them.
But I went ahead and bought new points because I could when I rebuilt some of the better coils he had saved.
Nowadays I still save good T parts as long as they are usable.
Points are still good as long as they have good flat surfaces and can be cleaned up pretty good with care and a good point file.

John,
I am in the process of referring a bunch of coils for some testing that I am doing.

I use wet/dry sandpaper wet with water and a course then a fine on top of a piece of glass. I heard of people using diamond hone and having good success (see this webpage for an example: https://www.grainger.com/product/3KT18? ... lsrc=aw.ds).

I have found the points are only one issue. More likely the nuts, studs, and place where the nuts/studs contact the points need to be cleaned. I wire wheel all of that. I have heard others have success with sand blasting that.

Matt

Yes sometimes the coils just need a good cleanup. I have noticed the fine thread screws and nuts have a copperish type of coating on them. Or at least that’s what they had once when new and over time they lose that and start rusting. That’s what I think anyway.

Even totally unusable ones have value. I use the brass top piece as key fobs on many of the keys I have, with my mobile phone number engraved on them. Those same pieces yield two brass washers when the mounting holes are cut off the ends. These are really handy when assembling points onto coils which have recesses in the wood tops from repeated fitting of points in the past. Just place one under each of the tubular spacers to restore the point to the correct height.

Allan from down under.

I have a suspicion that the hard material does not extend all the way down to the steel/brass backing. I have found that very thin points I have smoothed and polished can rapidly deteriorate and become burnt.

Can anyone confirm or contradict that?

I don't have any "official" information on whether the points are of composite construction or not, but I doubt it. I don't think it would be worthwhile, and the Ford service book does not mention it when addressing point refurbishment. Rapid point deterioration is often due to contamination, an off-spec capacitor, or high current draw due to improper adjustment or other factors. A soft file or oily stone might leave material on the points, which could lead to burning. Ambient dust or oil fumes can also shorten point life.

A Montana 500 Guru introduced me to the EZ lap diamond hone (fine) for refurbishing dirty/worn coil point contacts. This hone is readily available, inexpensive (<$10) and think it works very well.

https://www.amazon.com/EZE-LAP-LF-Fine- ... 158&sr=8-4