Repairing Rusty Electrical Connectors

Scott Buchanan a =E9crit :

Good idea, just fill the connector with Nylogel or any other dialectric grease

Idiot: Do you know what dielectric means?

No, don't coat them or tin them or anythign else. Clean and replace as necessary. A light coating of grease will sometimes help AFTER the connections are tight, but once they're rusted the protective coating is gone and cannot be replaced. They're cheap - much better to replace them.

Pop

Replace them. Apply dielectric grease to the new ones so that this doesn't happen again.

Once they are rusted, there is no way to get a nice clean tinned surface again.

--scott

So you're saying they can't be electroplated? Isn't that how they were made in the first place? I know I've seen DIY instructions & kits for electroplating all over the web. A simple google search for DIY electroplating should get thousands of results. I'm wondering if there's some reason they can't be used for electrical connectors.

Of course new ones aren't real expensive. Fixing more hassle that the new ones are worth maybe?

Cheers, - JJG

The problem is that the original metal underneath is now pitted. If you remove the rust from the surface, you now have connectors that have an uneven and pitted surface. If you plate over the pitted surface, you get an uneven and pitted plating.

Most of those connectors were probably hot-dipped in tin rather than electroplated. You could electroplate them, but it might be easier just to dip them in a solder pot. Regulate the pot temperature to adjust the thickness of the coating. The nickel-plating pens would work, though, IF you could get the original surface smooth and if IF the original metal has not become brittle.

It's more than just hassle, it's the fact that you'll find most of those connectors are pitted and even if you're willing to spend a couple hours on each connector with a Dremel tool smoothing down the finish, you're going to wind up with thin and breakable metal.

Note that a lot of those contacts are spring steel, and after a few years they are no longer springy. It is possible to re-anneal them on the bench with a jeweler's torch and a small furnace made from firebrick. It will cost you a lot time and a lot of money in gas, though.

I think it's a bad idea, though, to put five or six hours work into a connector that sells for a dollar or two, especially when the end result will be a connector that is less reliable than the replacement.

--scott

When I redid my Jeep, I replaced all the rotted ones. I found the wires were even rotted at the connection buried in the rubber so there really isn't much there to fix.

I got lucky and a friend gave me a used harness out of a full sized GM van for a hand I gave him so I just cut out all the bad ones and used solder and heat shrink with dielectric grease inside the heat shrink to replace them. I also used dielectric grease inside each. My Jeep uses GM connections.

I figured that was the best way to go short of rewiring. I did change wires that were discolored while I was in there.

Mike

Scott Buchanan wrote: ( '63 Corvair )

Some of the electrical c Fill the c Idiot: Do you know what dielectric means? __________________________________________

Dielectric means electrically non-conductive.

Homer is correct - if an electrical connector is to be filled with grease to prevent further corrosion, the grease must be dielectric.

Rodan.

There are tin plating solutions that may help, provided you can first remove every bit of the corrosion. They're sold by electronics supplies and are used for tin plating copper circuit boards.

Are the connectors made of steel, or are they tin-plated brass? Bare brass will work.

Apply silicone grease to the connectors before plugging them in so the grease seals better. This will not interfere with the electrical conduction since the metal will pierce the film of grease.

You coat them with grease before, not after, making the connections. The metal will pierce the film, so the grease will not impede conduction.

Replacing the connector is a no brainer, the big issue is the steel the screw bites into. I recommend a gentle blast with a hand held spot blaster, than apply some tinning compound, heat the tinning compound [ propane torch ] until solder beads form, than wipe with wet rag, reheat, and apply some plumbers solder to the tinned area.

After a through cooling, sand lead smooth, fasten replacement connector with a stainless steel screw, paint connection with whatever your using on chassis. I did this 20 years ago, and the tail lights are still bright.

Thanks for all the responses. At least most of them.

It looks like that I was too vague on what I was trying to do. The rust is on the 1/4" wide, male, blade connectors on the back of the heater switch. They are plated steel. They are riveted to a phenolic block so it can handle heat ok. The rust remover took off most of the rust except what was in the pits. Sand blasting took care of this.

This is mostly a learning process for me. I may be able to find a good replacement switch, but I want to learn how to fix it in case a replacement was not available.

Thanks, Scott

Paul

What is tinning compound? Does steel need a special flux? I have some lead-free plumbing solder with silver in it.

Thanks

On those, I use new female connections and dielectric grease once the spades are cleaned up. The new female connectors will be nice and tight again. Alternately I have taken the female side out and carefully squeezed the side rails down to make them tight again.

The old pins can be removed from the plug using a mini screwdriver down the back side of them, then new female spades can be crimped back onto the wires and put back into the plug or just plugged on directly.

I have also soldered the spades to coat them with iffy success, you have to get 'all' the flux off or it will cause fast corrosion. I found the solder didn't want to go on evenly so it was a bugger to get the female side on over it and have it stay tight. The solder is pretty soft.... The solder works to hold the pin onto the rivet well though.

Mike

I don't know what the chemical is, but it's a liquid that coats the metal with tin after it's dipped in it for several minutes and is used for making circuit boards easier to solder without having to remove the copper tarnish. Here's a description of one type:

The kind I used was from GC Electronics

I've used ammonium chloride (acid flux, common) and regular rosin (non-acidic) on steel, and if you clean the steel and then apply rosin flux to it, it should make it much easier to apply solder, even solder that contains its own flux. But plenty of heat always helps make the solder stick and flow better.

This stuff does not work as well on steel as it does on copper, but it can work. The metal underneath must be IMMACULATELY CLEAN with no oil residue (not even fingerprints) on it. It is not as effective as a dip but it works at room temperature.

--scott

Using your ideas, this is what I did. I applied some kind of liquid flux to the sand blasted surface. Heated the metal with a soldering iron. The a lead/tin solder did not flow well so I rubbed the solder into the surface with the iron and it seemed to cover well. The solder was very thick so I used some de-soldering braid to wick off the excess solder. This left a nice shinny and smooth coating on the connector. Unfortunately, some of the flux also remains and it is difficult to remove.

Next time I'll try another type of flux and maybe some silver solder.

I am checking into that tinning compound. Some of the parts cannot handle heat well. It might work to re-plate fasteners too.

Thanks

If it's rosin flux, you don't have to remove it.

For the most part, I think you are MUCH better off replacing all of the connectors if you care even a little bit about reliability.

--scott