Uhlmann body cord pin corrosion

[counterattack]

I am having an issue with the pins out of my Uhlmann body cords. I have pulled the pins off and I was going to cut some length of the wire on the cord to get the resistance back down to ~0. But then I measured the wire itself and it was fine. The resistance is actually all in the pin. From the square body of the pin out to the contacts measures 60 ohms. When I inspect closely I see that right where the contacts meet the rounded part of the main body there is corrosion. I am sure someone else must have seen this but I couldn't find anything via search. Is there a way to clean this out? Anybody know how the contacts are actually connected inside the body? If I twist hard enough can I spin the contacts? It seems they must not be fixed with anything solid or else I wouldn't be able to get high resistance. But if it is just press fitted then I could possibly spin it. Or perhaps there is something I could soak it in that is decent at removing the corrosion? Or perhaps I can use a heat gun and get the whole pin hot enough to solder a new connection? Any suggestions?

[JayhawkPawn]

Rarely will I say this, but save yourself time, money, effort, and hatred. Go buy some LP bodywires. Hopefully you're not using two-prong, because two-prong weapons are creations of the devil. Leon Paul makes a good wire, just don't step on them, I've had to buy too many of those crunchy little plastic pieces.

Or you could just bastardize it, and buy a LP connector, their solid pins are the best, and with a little bit of sandpaper, you can have your zero ohms back.

[Beowulfman6]

There are basicly three styles of pins-

The basket kind that have the separate piece that is wrapped around the pin is the worst for corrosion and the least reliable- I don't use this kind.

The type that has two (sometimes three) strips of metal bent over the pin longitudinaly is much better- they need spreading less often and are less suceptibale to corosion.

The flat-out best type is the LP solid pin. Becouse it is solid you never have to sread the pins and the most you ever have to do to get rid of corrosion is rub it a little with some sandpaper. I personaly don't use LP now, but any future plugs it buy will probably be LP.

About the only thing you can do with the ones you have now is clean them with sandpaper as best you can.

Originally Posted by JayhawkPawn

Rarely will I say this, but save yourself time, money, effort, and hatred. Go buy some LP bodywires. Hopefully you're not using two-prong, because two-prong weapons are creations of the devil. Leon Paul makes a good wire, just don't step on them, I've had to buy too many of those crunchy little plastic pieces.

Or you could just bastardize it, and buy a LP connector, their solid pins are the best, and with a little bit of sandpaper, you can have your zero ohms back.

The LP's are costly, but they are a superior desighn. I disagree on the bayonet thing though. I have used both and while I have said it here before, here is what I don't like about them:

They have many moving parts
They come apart easily and scatter the above parts everywhere (springloaded).
They are more difficult to fix
They have screws that have to be adjusted correctly to work.

[brtech]

Sounds like you have "basket" pins, made in two pieces, a solid center pin, and a basket of springy metal leafs surrounding the center post. The basket should spin relatively easily around the center. If it doesn't, twist it until it does. Very, very occasionally, you have to use something like "Brake Free" to loosen up the basket.

That will almost always fix this kind of problem, although 60 ohms is really off the charts and I'm suspicious that there is something else going on here. You may have to replace the pins.

While I appreciate the longevity of the LP design, it has it's flaws, the most notorious of which is that the screws loosen and/or corrosion develops between the screw and the wire, requiring frequent maintenance.

One other problem we see occasionally is that sometimes the plastic part that holds the pins break, A lot of people ignore this problem and continue to use the cord. This is a mistake. If you look at an intact LP 3 pin plug, you will see that the pins are not co-linear, the middle one is offset. The plastic deforms a bit when you put the plug in the socket, which has the holes exactly on a straight line. The plastic acts as a spring, and holds the pins in the socket by the deformation. If you break the plastic, that doesn't happen any more.

Also, I personally think that if you buy into LP, you have to buy into the system, because the wire they use is matched to the pin design. I see people trying to use non LP wire with LP connectors, and I think they have even more problems. For example, the screw has a pointy end and is designed to pierce the insulation of the wire. When you use non LP wire, it usually doesn't fit in the hole, so what you have to do is strip the wire before you put it in. However, now the screw is not piercing the insulation, and, I believe, is more prone to loosen. It seems to me that the fact that it has to be forced into the insulation tends to hold it more in place than just smashing it down on uninsulated bare copper.

[oiuyt]

Originally Posted by Beowulfman6

The LP's are costly, but they are a superior desighn. I disagree on the bayonet thing though. I have used both and while I have said it here before, here is what I don't like about them:

They have many moving parts
They come apart easily and scatter the above parts everywhere (springloaded).
They are more difficult to fix
They have screws that have to be adjusted correctly to work.

Or for an even superior design without most of the flaws you've listed, try the Italian bayonet designs (Negrini or Carimari).

More difficult to fix is really the only one that still applies. MUCH less frequent repairs. Much more solid attachment than 2-prong or LP-style bayonet. Very good retaining device. Minimal moving parts.

-B
(for reference, I have LP-style bayonet on my foils, Negrini on my sabres)

[Inquartata]

Right, but how do you get them, other than ordering from Italy?

I mean, if the only way to find wisdom is to climb a mountain in the Himalayas to talk to the hermit, I'm going to do without. Some things just aren't worth the extra trouble.

[brtech]

Originally Posted by Inquartata

Right, but how do you get them, other than ordering from Italy?

Several vendors carry Negrini: American Fencers, Sword Masters and Absolute for example. I don't know of anyone carrying Camamari,

[Inquartata]

$45 for a body cord and $16 for a socket! Ay caramba!

[Beowulfman6]

Originally Posted by oiuyt

Or for an even superior design without most of the flaws you've listed, try the Italian bayonet designs (Negrini or Carimari).

More difficult to fix is really the only one that still applies. MUCH less frequent repairs. Much more solid attachment than 2-prong or LP-style bayonet. Very good retaining device. Minimal moving parts.

-B
(for reference, I have LP-style bayonet on my foils, Negrini on my sabres)

Originally Posted by Inquartata

$45 for a body cord and $16 for a socket! Ay caramba!

I am familiar with the Negrini, but the cost, as mentioned above, in addition to the fact that no body uses them (making it harder to bum a replacement when your's all fail) keeps me away. 2-prong is, all things considered a good desighn.

[counterattack]

Originally Posted by JayhawkPawn

Rarely will I say this, but save yourself time, money, effort, and hatred. Go buy some LP bodywires. Hopefully you're not using two-prong, because two-prong weapons are creations of the devil. Leon Paul makes a good wire, just don't step on them, I've had to buy too many of those crunchy little plastic pieces.

Or you could just bastardize it, and buy a LP connector, their solid pins are the best, and with a little bit of sandpaper, you can have your zero ohms back.

Of my nine body cords six are Prieur. I don't understand people's hatred of the basket. I like it. I just gently squeeze it with pliers and turn it around a few times and it scrapes the corrosion right off. And the wires are easy to do field repairs on. That is worth all the other issues as far as I am concerned.

I just got my first Leon Paul body cord last week so I can't comment there. I just worry that nothing in the construction attempts to keep moisture out, but perhaps that is a lost cause anyway, so having such open construction at least allows good evaporation.

My two Uhlmann cords I have had for years, but they can only seem to stay working for short periods. I just decided to fix them again but from the responses I see that it is pretty much a lost cause. There is no way to get sand paper into the area where the corrosion is, and seems to be no other way to clean it. Oh well. I'll donate all the parts except the bad pins to the armory and move on with my life.

Philip

[Purple Fencer]

Originally Posted by counterattack

Of my nine body cords six are Prieur. I don't understand people's hatred of the basket. I like it. I just gently squeeze it with pliers and turn it around a few times and it scrapes the corrosion right off. And the wires are easy to do field repairs on. That is worth all the other issues as far as I am concerned.

The major issue with teh baskets is they get smashed flat eventually, make it necessarry to get the teeny screwdriver and spread them out again so they maintain contact in the socket...squeezing it with pliers actually speeds up this process...poor contact in the socket is more of an issue than corrosion, from what I've seen.

"Leon Paul Disease" is easy to fix...just back the screw out a turn and crank it back...amazing how the resistance drops like a rock.

Because My American cords use the same connection system, they ARE susseptible to LPD....but the other issues related to the basket they do NOT have.

[brtech]

Originally Posted by Purple Fencer

Because My American cords use the same connection system, they ARE susseptible to LPD....but the other issues related to the basket they do NOT have.

Huh, I thought they were closer to the Prier with the wire going in straight and a screw on the side. Is it an insulation displacement screw with a pointy end?

I've often wondered about LPD; it seems so unlikely. Usually when you crank a screw down into soft metal you get a kind of cold-weld effect where the soft metal molds around the point and grabs on. I doubt you actually get any screw metal mixing with the copper, but what, exactly, happens? Does the screw back out due to vibration? Are we seeing dissimilar metal corrosion? Is the connection not really air tight enough to prevent corrosion?

The same screw on stranded wire happens on all pins. The differences are the metals used and the shape of the screw end where it contacts the wire. Something allows LPD to happen on the LP pins, but not on the french or german style. They use brass screws, right (the Uhlmanns are plated, but I think they are still brass, not steel)?

Anyone got a clue?

[Purple Fencer]

Originally Posted by brtech

Huh, I thought they were closer to the Prier with the wire going in straight and a screw on the side. Is it an insulation displacement screw with a pointy end?

The wire does go straight in like Prieur and the screw's on the side...but it has the pointed screw like an LP (although the dimensions are different)

[qoute]I've often wondered about LPD; it seems so unlikely. Usually when you crank a screw down into soft metal you get a kind of cold-weld effect where the soft metal molds around the point and grabs on. I doubt you actually get any screw metal mixing with the copper, but what, exactly, happens? Does the screw back out due to vibration? Are we seeing dissimilar metal corrosion? Is the connection not really air tight enough to prevent corrosion?[/quote]

Urgh....I need an engineer to answer that one...Mergs?

On screws backing out, i don;t see that very often with actual LP plugs....waaaay too much screw makign contact with the tapped recieving port to vibrate out too much.

The same screw on stranded wire happens on all pins. The differences are the metals used and the shape of the screw end where it contacts the wire. Something allows LPD to happen on the LP pins, but not on the french or german style. They use brass screws, right (the Uhlmanns are plated, but I think they are still brass, not steel)?

Anyone got a clue?

I thinkt he Uhlmanns are steel screws...the heads don;t break off like the brass of Prieurs (which is why my screws are steel...)

The best person to answer teh LPD question would be Alex or Barry Paul...
I'd kinda like to know myself why the corrosion happens.

[Mergs]

Another thing that might be considered is using Vaseline (the old fashioned, petroleum jelly) to help prevent, or at least slow down, corrosion. It's great for water repellancy (ask any baby's bum) AND it's conductive!

Just a thought.

[Barry Paul]

In the U.k. no body ever checks the resistance of the body cord except at the two F.I.E. A grades we have. In order to get a white light you need a total of 200 ohms? (no doubt some one will correct me.) So whether the body wire has 1 ohm or 10 ohms will not in 99% of cases make any difference.

Thats why Leon Paul has up to now not been concerned about a slight rise in resistance, which is easily remedy by re tightening the piercing screws. If it is really an issue I suppose we better look into it. Will report back in a couple of weeks.

[Purple Fencer]

Originally Posted by Mergs

Another thing that might be considered is using Vaseline (the old fashioned, petroleum jelly) to help prevent, or at least slow down, corrosion. It's great for water repellancy (ask any baby's bum) AND it's conductive!

Just a thought.

How would you use the vasaline, Mike?

(all you dirty minds, SHUT UP! )

[oiuyt]

Originally Posted by Inquartata

$45 for a body cord and $16 for a socket! Ay caramba!

I bought plugs and sockets, rather than cords and sockets. Used the plugs to retrofit some old cords from other manufacturers.

How often do you need to replace such things? How much other money does a national-level competitor typically spend over the course of a season? A $16 socket vs. a $5 socket is a rounding error. $10 +/- on a plane ticket wouldn't be particularly noteworthy. A couple of extra tournaments over the course of a season will cost more.

Is it a bunch of money in one chunk? Yes, for most of us. I decided that I needed at least 4 cords and weapons given the paucity of borrowable replacements. Over even a moderate span of time, however, this just isn't a huge additional cost.

-B

[Inquartata]

Originally Posted by oiuyt

A $16 socket vs. a $5 socket is a rounding error. $10 +/- on a plane ticket wouldn't be particularly noteworthy.

Meh, coaching must pay really well, I guess!

( Or else refereeing does. )

Are you sure there is no politician blood in your family tree, to explain such a cavalier attitude toward money?

Or do you just hate people asking to borrow gear from you that much?