Basic Silver Soldering With Strong Joints

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Introduction: Basic Silver Soldering With Strong Joints

In this Instructable, I'll show you the absolute basics for making silver-soldered joints that are simple, and structural.

To accomplish this, these are the MAIN tools and supplies needed:

These accessories are a little more on the optional side, but highly recommended:

For safety when soldering or welding, use a respirator mask rated for gas/vapors. This is the respirator and cartridge combination I use:

If you would like to see the process from start to finish, including an example of joint strength, check out my video.

Step 1: Clean and Prepare Your Metal

The basic idea with silver soldering is less about "melting silver" and more about heating two separate pieces of metal to a point where the silver will flow onto and between them. This silver will then form a bond between the two pieces of metal. In the case of a high-silver solder like I use (Harris Safety-Silv 56%), the bond is VERY strong. As I show in my video, the joint can take significant stress and bending.

Before applying the solder or heat, each of your metal pieces has to be cleaned, especially if they are oily or rusty. I accomplish this with sandpaper. If it's really bad off, start with a file, then sandpaper.

Step 2: Apply Flux

Soldering flux must be applied to each metal surface at the joint. Flux prevents oxidation during the heating process, allowing the solder to flow properly onto/into those areas.

Step 3: Cut Your Silver Solder

While you CAN simply apply the silver solder directly from the roll while you are torching, you may end up using much more silver than you need to. I prefer to cut an appropriate-sized piece of silver solder for the joint.
Once you have your silver solder pieces cut, go ahead and apply flux to them as well.

TIP: For some joints, it may be easier to hammer and flatten the silver solder. You can also bend it to a curved shape or whatever you'd like, to help keep it in place while torching.

Step 4: Position Your Parts and Solder Pieces

Using your "helping hands", titanium clamps, metal assistance wire, or whatever your preferred clamping/holding setup may be, situate the pieces as you want them to be, and ensure they are butted together as CLOSELY as possible. You don't want any big gaps here. Silver solder flows well into areas that are tightly fitted.
Carefully place your silver solder pieces on top of the joints. The paste flux helps hold them in place initially.

Step 5: Apply Heat

Once everything is in position, you are ready to turn on the torch and apply heat.
(I almost always have to dial the heat back on my Mapp gas torch. You will get a feel for how much is too much.)

Start by moving the flame around the entire area, BROADLY sweeping in a circular motion.
At this point, you want to heat the METAL, not the solder!
Pay attention that you apply heat to BOTH pieces as evenly as possible. Thicker pieces require a little more heat. If you heat one side up too much, the silver will head in that direction. (But if that happens, "pull" it back by applying more heat to the other side.)
If your solder starts to move away from the joint, use your titanium pick to gently nudge it back into place.

The flux will bubble, and the silver solder will look really shiny, and eventually melt.
You want to watch that you don't make it bright orange. A DULL RED is ideal, and that's when the solder should flow.

Once the silver flows into the joint, give it a couple extra seconds of heat and pull away.

Turn off your torch and let the piece sit, undisturbed, until it cools completely. Do not quench in water.

Step 6: Pickle (or Just Sand It)

Once your piece is cooled, you can remove the clamps and it should all hold together on its own.

You'll notice the burnt flux and oxidation, which you'll want to remove.

You can use a "pickle" for this (see video for recipe) or you can simply sand it. My favorite way to finish the piece is with a wire brush attached to a drill.

Step 7: You've Got a Strong Silver-soldered Joint!

Give your joints a little twist/bend to be sure it's secure. I'm not saying to bend it out of whack, but just check to make sure it feels good and strong. :)

At this point you can apply a clear coating to your piece to prevent oxidation/rust, or you can leave it as is.

Harris Safety-Silv 56% works with steel, stainless steel, copper, brass and other metals. With stainless steel in particular, you can get some very nice, color-matched joints.

Step 8: Get Creative!

Have fun with it! My favorite part about this process is looking for metal pieces to combine and turn into something. Most often, I make little characters out of old nails, nuts, and bolts.
If you are interested in my work, please visit my Etsy shop:
https://www.etsy.com/shop/steadycraftin

Hopefully you have learned something from this tutorial. Thank you for watching and reading!

Your friend,
TheCrafsMan
SteadyCraftin

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73 Comments

Thanks for posting this, I find your instructable very helpful and I love your creations! :)

1 reply

Glad to hear that, Gadisha! Thank you for checking it out!

Do you have any thoughts on using some sort of oven for the heat source instead of a torch? I was thinking of building a small oven with fire brick and a cal rod from an old electric cooktop.

6 replies

Kiln soldering works OK but I doubt you will get up to 750ºC (nearly 1,400ºF) to melt silver solder using just an electric cooktop.

If you have a technique to modify or overdrive the element up to 750ºC post it here as far as I know most cooker elements are intended for less than a few hundred degrees.

A torch & fire brick is faster, easier and simpler for soldering, items can move as flux & solder flows & the metal expands, you can't easily deal with that in a kiln, spring clamps will also weaken as you get up to temp, so they may be ruined in a kiln.

Thanks for the response. I've seen those electric heating elements glow orange-red when they are at full blast with no pots on them, my Grandma's old GE stove did that often. From this link below and my memory I would guess that they reached almost 900C:

http://www.blksmth.com/heat_colors.htm

So I think building a K-23 firebrick enclosure around such a heating element might work. I'd agree with you and TheCrafsMan that fixturing would be a lot more difficult, though. But my goal is to repair a tiny item that I could never hold in place accuately by hand, so I already need to machine some sort of fixturing. I guess I'll need to make it from steel, not aluminum.

I think I'll try it, if it fails miserably I'll let you all know!

This looks like an impressive electric kiln for melting aluminium that made me remember this topic.

Kids eh…

:)

I still wouldn't use it for soldering but the project looks nice.

As a jeweller I have soldered 'tiny' items by hand with a torch & tweezers. It is simply a technique that requires some practice to learn but can be picked up if you are willing to invest time experimenting & have some aptitude for practical working. Ideally use similar metals to learn, copper, brass, nickel, gilding metal and silver can stand in for gold & other precious metals.

If the kiln idea works best for you, go for it. I just think that there are existing methods to make soldering easier, for example steel wire is often used to hold parts whilst soldering jewellery - lookup soldering with binding wire e.g…

Spring tweezers also help to hold jobs in some cases (& can sink some heat away)…

https://www.amazon.com/Testors-8942T-Reverse-Actio...

Flux & solder have a habit of moving as they are heated & melt - you can easily address that by hand with a metal soldering 'pick' & extra flux (an old needle file or similar works fine). If using a kiln you will need to let the work cool enough before moving to check a joint, so it could take some time to make the same alterations.

Generally solder moves towards the heat (provided it is fluxed) which a torch controls easily, I don't know how you would do that in a kiln setup with any degree of accuracy.

For ultra fine jobs you need to use a micro torch, often an acetylene based torch is used (or laser/ electrical welding) but that is not required for most handmade jewellery.

I have also seen electric heating elements get up to red heat but I haven't tried building a kiln with them for heating other metals to solder - a torch is how I learned the process.

Good luck with whatever you decide, learning is part of the fun.

That's an interesting thought. I'm not sure that it would be very convenient. You'd want to be able to remove the items from the heat once the solder flows, so that it doesn't just stay melted. The items holding your pieces would also need to be able to stand up to the heat. Whereas with a torch, you can concentrate the heat toward the joint, and less on the surrounding objects. Hope this helps!

You would need an extremely hot oven. Don't forget the parts have to be red hot.

Any precaution's or advice on using this technique on thin brass?

I have a glass lamp shade framed with 3/4" wide thin brass that holds the glass pieces and several joints of the brass have come un-fastened.

Any & all advice will be appreciated.

Thank you for the well done, informative & "cool" video.

2 replies

Thank you for checking out my Instructable and video! Do the joints come un-fastened during soldering (heat)? If so, you can apply a damp cloth/paper towel or heat sink to keep them from melting when you're soldering a nearby joint.

Will do!

'preciate your time, effort and sharing your knowledge.

Warren

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Thank you for the very good tutorial.
Can you please tell me where I can buy the silver solder and the flux?

3 replies

You're very welcome! Thanks for taking time to check it out! :)
I buy the silver solder and flux from Amazon. Here are the links:

Stay-Silv Flux:

http://amzn.to/2yuLPgH

Safety-Silv Solder - 56% (You can get cheaper silver solder, but I get this for the strength)

http://amzn.to/2zjA2ky

The picture of the soldier on Amazon looks brass colored. Is this the same stuff you used in the video?

It's actually an old steel key and some cut nails. I leave a lot of the older rust-ish patina, as I like the aged appearance. :)

This is so amazing! I have been trying to figure out a way to do something like this as compared to the soldering with wire. Thank you for sharing and congrats on the great instructions! Can't wait to try this!!