125 How to Solder Aluminum to Stainless Steel with Super Alloy 1 Multi-Metal Solder
Super Alloy 1 multi-metal solder can be used to join a variety of dis-similar metals. In this video, learn how to solder aluminum to stainless steel with a propane torch. Previously, joining aluminum to stainless steel was considered “impossible” in the welding community. Fortunately, Super Alloy 1 solder and flux kit makes easy work of this seemingly impossible application.
This same technique can be used to solder many metals, in any combination:
- pot metal
- zinc die cast
- stainless steel
Pre-cleaning both the aluminum and stainless steel are necessary just prior to beginning to solder. Failure to pre-clean the aluminum and/or the stainless may result in improper bonding, causing the finished solder joint to fail.
Super Alloy 1’s unique flux works as a visual temperature guide, turning root beer brown color when the aluminum and stainless steel have reached the proper working temperature of 350°F. When the flux changes color, apply the Super Alloy 1 solder where the aluminum and stainless steel form a joint. Note: If the flux turns black, simply remove it with a wire brush and warm water and begin again.
Tip: Indirect heating is very important when using this duo. Direct heating of the aluminum or stainless steel may result in overheating/melting the parent metal.
While almost any torch system can be used, we recommend larger torch tips to broadly heat the work piece. Oxyacetylene can be used with the oxygen turned low. A heat gun can also be used with this low temp solder.
ProTip: Keep the torch moving at all times to avoid overheating the aluminum and/or stainless steel
Allow the aluminum and stainless steel to cool naturally, then remove flux as directed above.
The final result is a 20,000 psi bond–aluminum to stainless steel.