On the subject of silver soldering...

[Cedge]

Here is a web page pointed out to me on another board I frequent. It gives a pretty decent tutorial for Silver soldering and shares a few tips and tricks. Polly Model's Basic Silver Soldering Techniques

Steve

 

[wareagle]

Great link! I haven't had much luck with soldering parts together, so I avoid this type of construction. But this gives a better understanding of the tricks to make it work well, so I may order the stuff and solder some scrap over the holidays.

Cedge, thanks for sharing!!

 

[Bogstandard]

If you have a look at my finger engine build it shows how easy it is to silver solder if you take it in logical stages and DON'T PANIC, and don't play the flame onto the solder, that should be melted by the parent metal alone. The three cranks were all soldered up in just over a minute using a standard gas torch.

John

 

[rickharris]

Hello My first post here:

As a hobby jeweller I silver solder as a matter of course with generally few problems provided the item is clean.
Silver solder comes in 3 general hardnesses - Easy, medium and hard - Personally I only use hard and have never had much problem.

As most jewellers I also use plain borax as a flux, this is easy to keep and prep for use with water or meths.

http://silversmithing.homestead.com/Soldering.html is a jewellers site with some interesting silver soldering information.

 

[Mcgyver]

Hi Rick, welcome and thanks for the link.

often different disciplines develop their own nomenclature, and I'm having trouble rationalizing the hard medium and easy handles....are they are particular to the jewelry area?

for example, generally all silver solders are considered to be hard solders - as opposed to silver bearing solder and soft solders. While there's lots of alloys, the differentiation is on melting temp and % of solder. Silver solders or silver brazing is those alloys melting at over 800F (450C) and generally have 40-60% silver there's also a huge difference in tensile strength ....like 10:1 or so.

further complicating things, the 'easy' makes me wonder if it has to do with Easylfow, a common brand name....... but easyflow is a silver or hard solder or silver braze.

anyway, I'd guess no one is going to know silver soldering better than a jeweler but I'm wondering what exactly what they mean by hard medium and easy solder?

 

[Oldmechthings]

Hard, medium, and easy, for silversmith's refer to melting temperatures. If you are building a piece of jewelery with lots of pieces that are too difficult to assemble all at once, two of more pieces can be fastened with hard solder. Then more pieces added with medium solder without having the first pieces fall apart. Then even more parts added with easy solder. Just barely enough heat is used to melt the solder in use, otherwise it defeats the whole purpose. Hopefully that clarifies the question.
Birk

 

[Mcgyver]

gotcha, I'm familiar with the different melting point technique, just didn't know the jewelers nomenclature, I'm used to thinking of them all as 'hard' solders.

 

[rickharris]

As said Easy - Medium -Hard applies to the melting point and so to some extent the alloy composition.

Silver solder = hard as opposed to lead based soft solders - I agree.

 

[Noitoen]

Last week I had a chance to try a trick I read somewhere, to limit the flow of solder all over the part being soldered. I didn't think it would work, but it did. The trick is to use a soft carbon pencil, (I used a B type) to outline a border where we want the solder to stop flow. I was soldering a little pipe nipple (3mm) to a small plate, so I drew a circle around the nipple, and the solder didn't flow over this line. I was surprised

 

[PTsideshow]

Last week I had a chance to try a trick I read somewhere, to limit the flow of solder all over the part being soldered. I didn't think it would work, but it did. The trick is to use a soft carbon pencil, (I used a B type) to outline a border where we want the solder to stop flow. I was soldering a little pipe nipple (3mm) to a small plate, so I drew a circle around the nipple, and the solder didn't flow over this line. I was surprised

Its the graphite in the lead mix that stops the flow, another item that can be used is the Liquid paper typewriter correction fluid in the bottles the white or colored material will also stop the flow(be aware that the fumes from the solvents used are toxic use in a well ventilated area).

Powered rouge(iron oxide) or whiting powered calcium carbonate mixed to a paint like consistency water or alcohol can be applied to areas that excessive heating of solder flow is not wanted.

You can also use garlic juice as anti flux.

Yellow ocher paste is also used, along with India ink(the carbon in it)

The best pencil to use is a #1 graphite pencil. As some of the pencils coming in from the overseas producers don't have as much graphite as they should and other stuff is being substituted for it.

Two important things to remember when using any of the anti flux materials.

1;Don't let the anti flux materials from mixing with the flux as it will render the flux less effective.
2: All the anti flux material must be removed before pickling the work as they shorten the working life of the pickle.

To direct the solder to were you want it to go, a sharpened TIG Tungsten in a wooden dowels will work as the solder will not stick to the tungsten. And that what's in the fancy ones from the supply house.

As for the solders available at most jewelry supply houses:
Easy Flo 1145'F 618'C
Extra-easy 1205'F 652'C
Easy 1325'F 718'C
Medium 1360'F 737'C
Hard 1450'F 787'C
"IT"/enamel solder 1490'F 809'C

The IT/enamel solder is used for attaching pieces together that will be glass powdered enameled in a kiln.

The easy flo has cadmium in it, the extra easy uses tin instead of the cadmium.

The higher the temp for the flow point of the solder, the more silver in the alloy and the less copper and zinc.

Some names of store bought fluxes

Battern's, Allcra, Hillco Fluoride/Boric acid based liquid flux
Handy flux, Dan-Dix Borax-based paste
Cuupronil is great for repair work
Prips flux excellent firscale protection
;D

 

[ozzie46]

Can you use the Benzamatic butane torches for silver soldering?
Will the mapp gas type with oxy bottle work?

Ron

 

[Mainer]

It depends on the size of the work. For really small stuff, a butane torch should be adequate. As the work gets larger, you need more heat-generating capacity. You don't need "high heat" in terms of temperature, just more of it. For what I've done, I've always managed with one, sometimes two, propane torches.

Kozo Hiroka did a really good writeup of silver soldering technique in his series on building the Pennsylvania Switcher engine.

 

[PTsideshow]

Here is the data for the assorted torches/flames
http://bernzomatic.com/RESOURCES/GASTYPES/tabid/222/Default.aspx

There are small propane/air torches that are designed for silver solder.
there are air/acetylene ( prest-o-lite ) now almost a generic name for them that have assorted tip sizes.
The mapp/oxy isn't worth it unless you all ready own it. as the cost of the bottles will kill you unless it is used only on occasion.

As been said depending on the size of the joint and the material heat transfer rate. Copper and its alloys are heat suckers. That's why most refridge repair heating and AC use at least at a minimum a air/acetylene torch. good heat and low cost even when you are using the smallest bottle an MC.

Here is another link to another threadhttp://www.homemodelenginemachinist.com/index.php?topic=2150.0
;D

 

[arnoldb]

Thanks to everyone who contributed to this thread :bow:
I was about to ask a couple of questions regarding silver soldering, and by browsing this thread and related links I got my answers

Regards, Arnold