Silver soldering is sometimes referred to as silver brazing or “hard” soldering where at least two parts are fused together by melting them and adding filler metal to the joint. The filler metal is melted to 420°C flowing into the joint.
Metallurgically speaking, a silver soldered joint is much stronger than a soft soldered joint as it consists of multiple layers and is linked to the joined parts’ surface. Why is it called “silver” soldering? Simply because the filler material used usually contains silver.
Successful silver soldering can unlock a lot of creative opportunities once you’ve mastered the technique. There are several different methods you can use to create a strong enough joint. The foundation of good soldering remains the same regardless of which particular soldering techniques you prefer.
For anyone new to this art or unsure about where or how to perform it, here is a quick guide.
What Is the Silver Solder For?
The process of silver soldering is used to permanently join two pieces of metal together by filling a prepared joint with pieces of silver solder using heat. It is primarily used with silver for silversmithing and jewelry making. It can also be used to fuse together gilding metal, brass, copper, and gold if needed.
What Are the Different Types of Solder?
There are four levels of silver solder–from hard to medium and easy to extra easy–all of which come in strip form. Silver solder can vary in melting point, depending on the type of solder used.
They should be used in sequence starting with hard, which has the highest melting temperature so that they can endure the long heating process. Hard solder will require a melting range of 745 – 780°C, medium solder requires 720 – 765°C, and easy solder requires 705 – 725 ° C while extra easy solder will require 655 – 710 ° C.
How Do You Heat Metal for Soldering?
The blow torch provides heat for silver soldering. You can choose a small and portable blow torch if space is limited in your workstation or a bigger or more complex one if you use it to connect to a gas bottle through rubber hoses. The size and intensity of the flame can be changed by a valve that regulates the mix of oxygen and gas used in soldering torches.
What Do You Use Flux For?
Prior to heating, a solder joint is applied with a cleaning solution called flux. Without it, solder won’t run, so it’s an essential component of the soldering process. Flux may come in the form of liquid or paste, and is usually applied with a paintbrush.
The Silver Soldering Process
For starters, the metal to be soldered should be cleaned and degreased with the use of emery and files, or wet and dry paper. Make sure the metal to be soldered is fitted closely together so that you wouldn’t be able to see past the joint.
You may now apply the flux to the fitted joint, and then gently heat it to dry. Tiny pieces of silver solder must be applied along the joint. It should also be clean with no traces of grease.
The next step should be to heat the metal with a fine flame, as evenly as possible. Watch closely as you keep the flame moving until the metal glows into a dull red. As it reaches the temperature, you will be able to tell whether your solder has run if you see a flash of silver. Remove the blow torch if you see it.
On a side note, if you didn’t see a flash of silver on the metal, it means the solder hasn’t run or formed a successful bond. In this case, you will have to clean your item before trying again using the same steps.
Finally, allow the metal piece to cool down, and then clean it with the use of a Pickling solution to remove oxides and dirt buildup during the soldering process. The solution can either be warm or cool whichever you prefer. Simply immerse the piece in it until sparkly clean.
How Can You Solder Safely?
You should be performing the craft on a heat-resistant surface that can endure and take in the extreme heat. A small working area will do but should be constructed using sheets and bricks that are heat resistant such as charcoal, asbestos substitute, magnesia, and the like. This should suffice for small soldering projects.
A soldering hearth with enough ventilation–but not so much that the breeze cools down the heating process–should be used for larger projects. Remember to observe safety precautions.
We hope this article was able to shed some light on silver soldering for those looking to venture into the craft. Silver soldering becomes easier for you once you have mastered this art; and with the right tools, you will be able to shift onto more difficult soldering projects in no time.
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