Brazing Cast Iron Exhaust Manifolds with SSF-6 Silver Solder

Brazing a Cast Iron Exhaust Manifold with SSF-6 Silver Solder and an oxyacetylene torch

This cast iron exhaust manifold has been cut to resemble a typical crack a consumer may encounter in a real life scenario.

We begin the repair by preheating the base metal with the oxyacetylene torch, to take the chill out of the base metal. Always broadly heat large masses before adding SSF-6 flux, to ensure proper flow. When the base metal changes color to a dull red, this is the indication to start painting the flux onto the cast iron manifold.

Notice the technique–flowing out each deposit of SSF-6 Silver Solder before moving on and applying flux liberally. SSF-6’s specially formulated flux coating provides twice the base metal cleansing action of conventional silver flux coatings and is essential to achieving optimum flow and bonding.

Be careful not to overheat the manifold–use just enough heat to bridge the gap.

SSF-6 Silver Solder is a high flow all-position rod with a working temperature of 1150°F, bonding even hard to reach areas. SSQ-6 Silver Solder Paste is the same dependable formula, in a handy oversized 1 oz syringe for easy application.

After completing the cast iron repair, remove the residual flux with warm water and a wire brush, then grind or machine as necessary.

As you can see, this is another perfect permanent repair using SSF-6 56% Silver Solder. Cast iron repairs will never be a problem again thanks to SSF-6.


• Be sure never to heat the base metal bright red or cool the repaired cast iron exhaust manifold with water
• Flow out each drop of rod before depositing more
• Create a flat braze to achieve the best seal
• Use flux liberally
• To ensure an even flow, broadly heat the parent metal throughout the repair


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