104 How to Solder a Broken Pot Metal Door Handle with Super Alloy 1
Classic car and antique auto parts were frequently constructed of “pot” metal–an inexpensive metal consisting of non-ferrous metals that have been thrown into a pot and melted down to create castings. Unfortunately, pot metal has a very low melting point, making it difficult to repair these sometimes irreplaceable parts. Thankfully, Super Alloy 1 pot metal solder and flux kit has a 350°F working temperature, which makes it the perfect solution to all pot metal repair projects.
In this video, a pot metal door handle with a missing piece is reconstructed using Super Alloy 1 and an oxyacetylene torch. Since we did not have the missing piece, we used a piece of wood behind the part to create a backer, then filled the gap with Super Alloy 1. Note: for this demonstration, we used oxyacetylene with a low flame, but a propane torch would work just as well.
Always begin any pot metal repair by thoroughly removing all the oxidation with sandpaper, emory cloth, wire brush, or Dremel tool. Bare metal is required for proper bonding. Next, dip the solder rod into the liquid flux and apply the flux to the work area. Gently and broadly heat the pot metal part, making sure to keep the heat moving to avoid liquefying the parent metal.
Next, watch the flux. Super Alloy 1’s unique honey flux changes from honey colored to root beer brown when it’s reached the proper working temperature, acting as a temperature guide.
When the parent metal has reached 350°F, begin to lay the solder rod in logs, filling the missing gap in the door handle. Add more flux as necessary to flow out the existing solder and flatten it out.
After completing the repair, allow the part to cool naturally, then remove any residual flux with warm water and a wire brush. The resulting repair can then be shaped and grinded as needed, and chrome plated.
- Always remember to turn the oxygen down with oxyacetylene.
- The best way to build up your pot metal again is to turn down your heat.