Soldering a cracked nickel ferrule

[osiris01]

Good evening folks,
I would like to repair a cracked Peterson ferrule with solder and I'm running into problems. I have a scrap ferrule to play with and the solder paste is not running smoothly into the crack or surrounding divot, in fact it looks almost as if it being repelled by the crack regardless of the direction I heat or how much use. It is tending to bead and run off wherever the hell it likes, or part fill a divot and refuse to fill the other half (yes, I know, I sound like a lunatic). I am using low temp (281F) no clean soldering paste (contains flux) and a heat gun.
At first I thought I wasn't getting the ferrule up to temperature before the solder melted, but when I pre-heated the ferrule the results where the same. What I know about metallurgy you could write on a stamp (in a foot note), but I do know that some metals resist solder to a greater degree than others and require specific flux to counter this, but by my research I should be good to go with nickel.
Any ideas anyone? I would really like to nail this as the join is practically seamless. Is a butane iron the answer, or am I using the wrong solder?
Many thanks folks.
Geoff

 

[elessar]

What kind of solder are you using? I have not soldered nickel but I would imagine it needs an aggressive flux. You may have the right solder but need a different flux. Brazing would probably also work but would need higher temps. If I were to guess I would imagine silver solder is needed with an aggressive activated flux. I have lots of welding, brazing, and soldering experience but never on nickel.

 

[cosmicfolklore]

First, there is a difference between pure nickel, and this nickel alloy. It has different names; German silver, white brass, nickel silver, etc... But, basically it is a brass alloy with a smidgen of nickel for color.
You would solder it (in jewelry, what we call soldering is the same as brazing in ironwork), but not "solder". The stuff that you can buy at the hardware store is not going to work. They sell a product called "silver solder" but it is for actually soldering copper pipes. You need to contact a jewelry supply house for real silver solder. It is sold in varieties, hard, medium, soft, extra soft, and your choice of wire, pallions, or sheet. You also need a formulation of flux called Pripp's flux, which is sold under many brand names. I prefer My-T-Flux, which is the color of Mt Dew. You will also need a pickle and a good torch. You can use a blue bottled propane plumber's torch. But, a soldering iron is not going to get up to 1200F which is required to make the solder flow.
Now, if you have used the stuff called "silver solder" that can be bought at hardware stores, it has no silver in it, and is named for its color, not content... if you have used this, the metal is now contaminated with zinc and tin, which will just eat up your metal if you try to bring it to temperature to solder with the real silver solder. So, essential it would be ruined. However, I use a technique of sweating it out of the metal using a charcoal vat and a kiln. But, if you have used the plumber's solder, this is way more elaborate than you can do at home without a proper silversmith studio.
I would suggest either looking for a replacement, if this is the case, or sending it to a jeweler, but you will have to tell them if you have tried to use plumber's solder. This will not be the cost effective way of repairing this. Sweating the solder out and then repairing it, would cost way more than just finding a replacement.

 

[cosmicfolklore]

Oh, BTW, breathing in vapors for white brass is putting trace amounts of nickel into your body. There is no way for this to ever leave you, and many develop an allergy to metals after working with white brass. This includes a sensitivity to tungsten and all white metals that causes you to be covered in whelps at the mere touch of these metals. One of my best friends has it from trying to solder some white brass years ago. And, he no longer works with any metals. I use a respirator when working with anything containing nickel or tungsten. Really bad shit.

 

[mau1]

Good posts, Cosmic. We're fortunate to have knowledgeable resources on this site. Your warning about the health risks are especially important.

 

[osiris01]

Yes excellent posts folks - thank you very much for your time. I had no idea of the health issues and I'm particularly grateful because I have just looked at what I thought I'd bought and what I received - and they are not the same.
I thought I'd ordered assay-quality easy silver solder paste (with a high % of silver) - what I received was the 'silver solder' that melts at 135c. I assumed silver solder was silver solder, but I guess this is NOT the stuff I want to be using. Fortunately no harm done to ferrule since it was a scrap piece (and hopefully no harm done to me since there's bugger all I can do about it now).
You have actually confirmed my suspicions - I was going to get a butane iron and silver solder strips but thought that the ferrule would just disintegrate if I blast it with 800C since it is very old and the area around the crack is very thin and damaged.
So, having demonstrated that a little knowledge is a dangerous thing, I conclude this is not the project where I learn to fix a cracked ferrule.
Thanks again for your sage advice.
Geoff

 

[didimauw]

Yeah, we get lucky and sometimes cosmic knows what he's talking about.
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