How to Silver Solder Cupronickel with SSQ-6 Silver Solder Paste

SSQ-6 silver solder paste is used to braze two pieces of cupronickel together with a propane torch.

Copper nickel or cupronickel is a widely used alloy in the marine industry due to seawater corrosion resistance. Cupronickel’s expansion characteristics, high resistance to biofouling, and thermal conductivity are the reasons it is found extensively in boat hulls, heat exchangers, brake tubing, condensers, power generation, shipbuilding, hydraulic lines, and piping applications.  Cupronickel is often chosen in hospital ICU or other sterile environments due to it’s antimicrobial qualities.

Cupronickel is commonly 95% copper and 5% nickel, 90/10 or 70/30 depending on the need.  90/10 is the most commonly used alloy–found in offshore oil and gas production, power generation, shipbuilding, naval and commercial shipping and more. 70/30 are used where greater resistance to sand abrasion, seawater flow, and wear are required.

To highlight the superior flow of SSQ-6 silver solder paste, we joined 2 pieces of cupronickel tubing with a simple propane torch.  One end piece of the tube was flared so the other could be inserted to create a tight fitting joint.  We applied a small quantity of SSQ-6 to the joint, then started the torch.

Notice the technique:  Move the torch side to side, heating both cupronickel pieces broadly and evenly.  This broad and even heating technique will eliminate the risk of overheating the copper.   As the solder/flux combination heats, notice how it begins to change.  The flux separates from the alloy and begins to direct the flow of the filler material.  As the product flows, the torch continues to move and direct the material.  SSQ-6’s flux pulls the alloy to fill the entire circumference of the joint.

After the material turns glassy looking, allow the part to cool and remove the excess flux.

Look at the beautiful end result, a perfectly color-matched 85,000 psi solder joint!


NotePlease observe all AWS Safety & Health Guidelines when using Muggy Weld products.

Caution: Do not store near edible items. If you refrigerate SSQ-6, please store in a “chemical only” designated refrigerator.