Soldering large jewelry pieces together?

[blue-sky]

Hi there,

I am somewhat new to metal jewelry and soldering and I have encountered a problem, maybe someone would have some knowledge to share with me regarding this topic.

So my problem is that i just can't seem to be able to solder 2 large pieces of jewelry together, one silver and the other brass.  When i do very small pieces it works just fine, with both soft benzomatic solder and medium silver solder. But with the large components, I can't seem to heat up the pieces to be hot enough to use with silver solder and when I use the soft  benzomatic solder, no matter what I do the 2 pieces will not join together--  the solder just turns to a ball.  Even when it does melt onto one of the surfaces, it just scrapes right off, so I don't know what I'm doing wrong.

 I now ordered some stay brite solder, maybe I will have better luck with it.  But  I am very unfamiliar with using soft solders, do you have to heat up both metals to very hot like in silver soldering for them to join with the solder?  Any tips or suggestions would be very helpful

Thank you!

[Russ Nobbs]

Lets see if I can give some suggestions.

What are you using to heat the item? I assume a torch? what sort?
What are you using for flux with each kind of solder?

Brass and copper suck up a lot more heat that sterling. It may be that you are getting the silver hot enough but the brass never does heat up enough.

The StaBrite is a very low temperature solder.It's basically tin with a small amount of silver to give a silvery color. Once you use it on a piece you can never heat the silver portion up to silver solder temperatures again. The tin will amalgamate with the silver to make portions of the silver melt away, becoming a lower melting temperature alloy.
The StBrite comes with it's own flux which you use liberally. Te flux cleans the surfaces of oxides so that the solder can flow.

If you want to stay with the medium silver I have one suggestion. Flux the brass piece. Heat it up so that the silver solder flows and "tins" the surface. Let it cool enough for handling. Flux the tinned brass piece and the silver. Lay the silver piece on the brass possibly holding them in place with some iron binding wire. Assuming you have a tripod with a steel mesh, put the pieces on the mesh. From the underside heat the brass up close to solder flowing temperature. Move the flame to the top silver part and start heating the  whole piece. At some point the solder shold flow from the tinned brass piece to the silver piece. Probably just at the point that the silver slightly slumps towards the brass part.

It's been a while since I did this. I think I'm right in suggesting you tin the brass item rather than the silver part since the brass requires more heat. But I could have this backwards. For that reason I suggest you experiment with a miniature version of your design, a smaller scale piece of brass that you want to "sweat" to the silver.

Working with large pieces of metal, like belt buckle size goods takes a lot of heat. It's not one of the easiest procedures.  Good luck!

[blue-sky]

Thank you so much for your suggestions.  Yes, I will try experimenting with what you said today. 

So for my torch I am using a Solder It brand which goes up to 2400F, on small items it works, but now I'm thinking maybe it's not strong enough to handle the larger metals.  Also for flux, I was using the Bezomatic soft solder with the flux it came in the package and on the silver I was using gel-flux.  But then i started using the jel-flux on the benzomatic solder because it was less toxic, but maybe that was a mistake. 

I'm going to give it another shot, I'll let you know if it worked!

[blue-sky]

Ok, so I realized that my Solder it torch is the source of my problem, it's not hot enough!

 I focused my heat on one end of my jewelry piece to melt some medium solder on it, after like 10 minutes of heating the jewelry part, i put some solder on it and it barely melted onto the piece.  Then i tried the center of my large jewelry component, i heated the area with my torch for 10 minutes plus, but it did not work to melt the silver, it was just too large.  So i just need to buy a smith little torch I think, acetalyne and oxygen can go up to 6000F  should do the trick, I hope!!

I will try again with what you suggested using a better torch once I purchase it:)

[Russ Nobbs]

I agree, I think the amount of heat you get from the Solder It torch in insufficient for your job.
The Smith Little Torch or a Hoke torch should be.
There is a newer product for the jewelry industry is adapted from the dental trades. The Miniflam Microtorch uses smaller oxy & fuel containers and is considered safer because of the small size. They claim it is hot enough for casting work and probably for your application.

Let us know how it turns out.

[Metalman]

Blue-Sky [ and Russ]
If I am reading this right - the torches you mentioned , while they are HOT - they don't have large enough flames for the work described. I would recommend a Smith 'SILVER SMITH '  torch - its an air feed [not compressed air] acetylene. You can get larger tips. Works good for up to a large belt buckle.  Any larger and I would recommend a Propane/ Mapp/ Natural Gas with a compressed air feed. -This gives you a large - but soft flame - hot enough but you can control it. The Oxy-acetylene torches are very hot - but they tend to be very 'pointed' or focused - hard to control on the larger.
Also using your soldering blocks you can build a containment area to help concentrate the heat - I frequently do this when I am doing workshops and only have my small torches with me.  Set it up so there are 32 walls and floor -put your pieces into the corner and try to heat the entire area - the solder block will [hopefully ] hold the heat
I am somewhat concerned bout the torches we are discussing as the costs are notably more than the little butanes or propanes a lot of folks are using

Hope this helps