I destroyed a connector today. The central terminal, silver metal, refused to be tinned despite my best efforts and while I was trying the plastic holding that terminal in place melted and the pin moved making the connector unuseable. This is not the first connector like this I have come across.

1. How do they get away with making such things?
2. Does anyone know a way soldering to these things?

 

What metal is that middle connector. Could it be aluminum?

 

What metal is that middle connector. Could it be aluminum?

I don't know what metal it is but it really can't be aluminium as you can, eventually, tin it which wouldn't be possible with aluminium and standard solder/flux. I suspect it may be a nickel plating but I have no evidence for that.

 

The central terminal, silver metal, refused to be tinned despite my best efforts ...

...but it really can't be aluminium as you can, eventually, tin it...

Confused: Can it be tinned or not?
FWIW: Aluminum can be soldered. Usually, a zinc alloy filler is used as a braze, but lower melting solders are also available.

 

Confused: Can it be tinned or not?
FWIW: Aluminum can be soldered. Usually, a zinc alloy filler is used as a braze, but lower melting solders are also available.

It can eventually be tinned but it takes a long time application of the iron and consequent melting of the insulator.
I know aluminium can be soldered but not with standard 'electronic' flux and solder wire.

 

use higher power solder iron.

 

The pin in this case is 2.5mm diameter and about 1cm long. Do you really think it would need more than 45W to get it up to temperature?
It certainly gets hot enough to melt the plastic.

 

Some connectors can be adequately heat sinked by attachment of the mating part such as an IDC socket to increase thermal mass during soldering. This also has the effect of fixturing the pins so that if some softening of the body plastic occurs, it resolidifies with the pins in the correct orientation.

 

Maybe the same problem: https://forum.caswellplating.com/fo...s/10134-soldering-to-nickel-plated-connectors

 

Some connectors can be adequately heat sinked by attachment of the mating part such as an IDC socket to increase thermal mass during soldering. This also has the effect of fixturing the pins so that if some softening of the body plastic occurs, it resolidifies with the pins in the correct orientation.

Good thought. That might work.

 

I also agree with @Ylee5763 as my first choice. I keep an 80W Weller attached to a Variac for that situation. Just a couple of weeks ago, I was modifying a small PCB for a model airplane speed controller. The contact, maybe 3 mm sq., was so well heat sinked that neither my regular temp controlled nor 25W Weller would work.

As for heat sinking, I have a variety of sizes of surgical clamps ("hemostats"). If I can reach above where I need to solder, I grab there; otherwise, I grab the far end. I have also found, as when soldering wires to pin headers, it is helpful to connect a socket to the not soldered ends of the pins.

 

Do you have any idea of the connector part # or take a pic.

Silver will tarnish and you will likely need a solder with a bit of silver in it. Silver also has high thermal conductivity.

Nickel might be troublesome to solder. That's why they usually add a layer of copper.

Flux may be important too.

I don't like Sn96 solder.

If you can braze or Silver solder that adds another layer of experience. I also have some working with quartz and Pyrex experience. I could not do anything pretty. No glass lathe. I could attach round tubes to square ones. Seal the bottom of square ones. Put a precision leak hole in a tube. Seal compounds under vaccum for synthesis and seal seeded crystal growth chambers. I did have to "practice" if I hadn;t done it for a while/

I did have a TIG, stick and MIG welder in my hand and did exceptionally well once I was set up.

 

It was a connector like the picture below but I don't know where I got it from. It was in my drawer and probably had been for quite a while which, if it is indeed nickel, makes solderability even worse.

 

I also have some working with quartz and Pyrex experience. I could not do anything pretty. No glass lathe.

Way OT, but having stepped in for the chemistry departmental glass blower (who are often compared psychologically to NFL goal kickers) when he resigned in a huff:
1) Pyrex/Kimax is far easier to work than soda lime glass. All you need is a natural gas and oxygen. Breakage on cooling and reheating is far less.
2) Quartz is relatively easy to work with hydrogen/oxygen. The only problems are: 1) You cannot see the flame; and 2) You need to be aware of the potential for flashback.

As one might say, a glassblower who needs a lathe is a weak/nervous glassblower.

 

It was a connector like the picture below but I don't know where I got it from. It was in my drawer and probably had been for quite a while which, if it is indeed nickel, makes solderability even worse.

That looks like a copy of a Switchcraft connector sold by the former Radio Shack with special easy-melt polypropylene insulator and unsolderable terminal plating.

Real connectors:
http://www.switchcraft.com/productsummary.aspx?Parent=1197

 

I never met the Aluminium in the connectors. However some metals used in older connectors may have that problem You mention. Especially if already oxidized. Then the standard methodes are rather few:
1) use instead of colophonia flux the 90% ortophosphoric acid. The fundamental wash after solder works are mandatory.
2) use the medical aspirin tablet, but look for old "stomack unfriendly" versions, otherhow nowadays "friendly" version of acetilsalicilate and acetilsalicyl acid is diluted by microcellulose what will cancel all of wanted efficiency. Thus, use like colophonia, but never transport by soldering hammer. Just put the piece in soldering place and heat it up. Take activity in well ventilated area, inhaling induce massive cough.
3) use the ZnCl powder in water about 50/50%. The simple Zn metal in HCl never hives a similar effect. Wash afterwards.
In Your case I would start with (1) and if not immediate result, then (2). However all three are those working on stainless, on high-carbon steels, on nichrome and manganin etc etc.

 

I have ordered some new connectors with a different style - hoping they won't have the same problem.
When I come to soldering I will engage them with the matching connector to hold the pin in place.
Also, I have ordered this which shoud sort out any really problem soldering but to be avoided if possible.

 

Mating while soldering on this type of connector may cause distortion of the receptacle pin, pushing it out of concentricity since the sprung outer contact holds the center pin under lateral tension when mated. Either solder unmated or create a heat sink that doesn't push the pin such as a piece of copper or brass tubing sized slightly larger than the pin and crimped to make a light friction fit on the pin.

 

It's nickel. Many such connectors are nickel plated and unbelievably hard to solder. In years long gone by, nickel plated connectors weren't particularly difficult to solder but the stuff out of China is just horrible. I bought a bunch of tip jacks on ebay. I wound up taking the plating off the lugs with a rubberized abrasive wheel ("Cratex" brand - very useful!) in a rotary tool because they simply would not solder otherwise.

A bigger hotter soldering iron will be of no help whatsoever. You might improve matters by lightly abrading the surface with fine emery or the like, but that is a pain to do on those things. I had some stainless steel MIG welding filler wire that just would not take solder no matter what flux I tried. A quick pass with some fine abrasive and it soldered easily.

 

If the connector does not tin very quickly then stop trying and use a hard metal object, such as a sewing needle to scratch through the plating. That is tedious but it does work. I have even soldered to some stainless steel in a camera that way. The guy at the camera shop told my son his camera needed a new computer for $320, so my son brought it home and asked what I could do. I opened the case and found a wire that had lost it's solder connection. So a minute of serious scratching and 5 seconds of soldering the camera was fixed. Of course it was good Radio Shack solder with some good flux as well. My son was happy and a bit displeased with the camera shop.