Cast Iron Revival: Restoring Pan Supports To Their Former Glory

Cast iron pan supports are prone to cracks and breaks, but they can be repaired without replacement. While welding is a commonly used method to join pieces of metal, it may not be ideal for cast iron. Other methods such as brazing, cold metal stitching, and epoxy putty can be used to repair cracks and breaks in cast iron without the need for welding. These techniques can help restore the functionality of the cast iron pan support and prevent further damage.

Welding cast iron pan supports

Welding is a commonly suggested method for repairing cast iron pan supports. However, cast iron is notoriously difficult to weld, and there are very few welders who have experience with it due to low demand. Cast iron welding is tricky because the metal must be preheated to a very high temperature, and the welding process must be followed by slow post-heating and shot peening of the entire pan for stress relief. A hole should also be drilled at the end of the crack to prevent it from propagating.

Several welding methods can be used to repair cast iron. One method is to use a nickel filler rod with stick welding. Another method is to use normal steel filler and hammer peen it while still hot. These methods can also be combined. A third method is brazing, which is generally considered easier and may be stronger than welding for cast iron.

When deciding whether to weld cast iron, it is important to consider the cost and benefits. Welding cast iron can be expensive, and it may be cheaper to simply replace the pan support. Additionally, the repaired portion of the pan support may not have the same cooking properties as the original cast iron, as it will have fewer internal air pockets and cure at a higher temperature.

Brazing cast iron pan supports

Brazing is a good option to repair cast iron pan supports. It is a process where only the filler material is melted, rather than the material being repaired. This means that the cast iron pan supports themselves do not need to be heated to an extremely high temperature, reducing the risk of warping. Brazing cast iron pan supports can be done with a brass or copper alloy, which melts at around 800°F, much lower than the melting point of iron.

Brazing is often considered easier than welding, and can produce a strong joint. However, it is important to note that brazing will result in a visible gold line filling the crack. Additionally, the repair may not hold up as well to heat cycles from cooking as welding might.

To braze cast iron pan supports, you will need to follow these steps:

• Drill a hole at the end of the crack to prevent it from propagating further.
• Clean and grind out the crack to create room for the filler material.
• Use a brazing rod or filler metal to fill the crack.
• Smooth out the bead on the cooking surface.
• Refinish the inside of the pan support as needed.

It is important to note that even after repairing cast iron pan supports through brazing, the repaired portion may cure at a higher temperature than the original cast material. This is due to the different internal air pocket structures in the repaired area compared to the rest of the cast iron. As a result, the pan support may not cook the same way as it did before the repair.

Additionally, when choosing a filler material for brazing cast iron pan supports, it is important to consider food safety. While the ferrous filler material itself is non-toxic, the flux and slag that remains on the weld during cooling may need to be scraped off to ensure it does not trap contaminants.

Cold metal stitching to fix cracks

Cold metal stitching is a popular method for repairing cast iron pan supports and is ideal for fixing cracks that cannot be addressed through conventional methods like welding. This technique uses specialised inserts to connect the damaged metal, regardless of the nature of the crack. Here's a detailed guide on how to fix cracks in cast iron pan supports using cold metal stitching:

Step 1: Diagnose the Crack

First, assess the crack in your cast iron pan support. Cold metal stitching is suitable for cracks in cast iron pieces with a thickness ranging from 3/16 of an inch to 1 foot. While the length of the crack is not as crucial, it's important to consider if other repair methods are more feasible or if creating a new cast iron piece is more efficient.

Step 2: Drill the Holes

Drill holes along the crack, spacing them at regular intervals. Using a guide ensures accurate drilling. The number of holes drilled can vary, but the goal is to create strong stitching points to hold the cracked cast iron together.

Step 3: Join the Rows of Holes

After drilling, connect the rows of holes to facilitate the insertion of metal keys, which will strengthen the cracked cast iron. Use a large chisel to join the holes without creating a slot in the metal. The round shoulders of the drilled holes will act as holding points for the metal keys.

Step 4: Insert the Metal Keys

Metal keys are the most crucial component of this process as they provide the strength to hold the cracked parts together. Use high-strength metal keys of the same length as the drilled holes to add strength across the entire surface, preventing further cracks. Ensure a snug fit between the holes and keys, with minimal play or movement.

Step 5: Sewing the Stitches Together

While the metal keys provide strength, they may not withstand intense pressure or heat on their own. Therefore, install screws between the metal keys to reinforce the bond. Place them close to neighbouring screws and the metal keys for a tighter stitch, enhancing the bond between the repaired metal and the cracked cast iron.

Step 6: Remove the Excess Material

Finally, use a chisel to remove any excess material from the stitching screws and metal keys. Then, use a grinding tool to sand down the remaining excess. Refinishing is essential to restore the cast iron pan support to its original state, hiding the evidence of repair beneath the excess metal for a seamless finish.

Cold metal stitching is a versatile and cost-effective solution for repairing cast iron pan supports and other items, preserving their functionality and original character.

Epoxy putty to repair cracks

Epoxy putty is an effective way to repair cracks in cast iron pan supports. It is a strong adhesive that fills in cracks and creates a safe seal. You can purchase epoxy putty at your local hardware store or online. Some recommended brands include JB Weld, Quick Steel, Brofix, and Superfast Steel.

Before applying the epoxy putty, prepare the cast iron surface by sanding the area with 80-grit sandpaper to remove any rust or paint covering the crack. Use a back-and-forth motion when sanding to avoid widening the crack. Once the surface is smooth and clean, use a cloth or rag, dish soap, and water to clean out the crack and the surrounding area. Allow the cast iron to dry completely before proceeding.

Now it's time to prepare the epoxy putty. Stir the epoxy according to the manufacturer's instructions. You may need to knead the putty by hand or use a putty knife to mix it on a flat surface, such as a piece of cardboard.

When the epoxy is ready, spread it into and over the crack. Scrape off any excess putty with a putty knife before it dries. It is important to wait a full 24 hours before handling the cast iron item to ensure the epoxy has cured completely.

If desired, you can paint over the newly sealed crack to match the rest of the cast iron pan support. Your pan support should now be repaired and safe to use!

Using filler bars for brazing

Brazing is an effective way to fix cracks in cast iron without welding. Brazing uses minimal heat to fix cast iron pieces, and is commonly used to correct cracks on cast iron items.

Filler bars used for brazing cast iron are often made from brass or nickel. Some fabricators and metalwork specialists use filler bars with flux, while others prefer to use a different flux during brazing.

After choosing your preferred filler bar, you must prepare the crack surface on the cast iron piece. Before brazing, the surface of the crack must be thoroughly cleaned to remove oxides and impurities. Using a grinder, the crack surface should be ground out to form a cross-section that is U-shaped. This procedure allows the brazing material to avoid stress concentrations and fully flow into the crack.

A stainless steel brush should be used to brush the ground area after grinding the cast iron piece. This procedure helps to ensure that any particulate that was left after grinding is removed.

The cast iron part is then supposed to be heated. Attempting to use a brazing torch on the cast iron’s cooler parts may cause further warping and cracking. Thus, other types of heat sources, such as a weed burner, an oven, or a gas grill, can be used to slowly heat the cast iron part.

The piece of cast iron is then placed onto a work surface and braced if necessary. During the brazing process, some significant parts may need heating, especially if the crack is substantial, and the process of brazing may take time. To maintain the temperature of the piece, it is recommended that you use an external heater.

You are then required to heat the crack’s surface by using a brazing torch to the point that it turns bright red. The filler rod is then placed onto the crack surface. For an effective brazing process, it is recommended that the surface temperature be extremely hot to enable the material of the filler bar to flow into the crack easily. While progressing down the crack, you may use the brazing torch to maintain the local temperature.

Finally, place the repaired part into a container full of sand and cover it entirely with sand. After the brazing procedure, the fixed amount of cast iron should be cooled very slowly. The cast iron may crack if it’s left out in the air to cool down. It is recommended that you leave the repaired part for at least one day in the sand and longer if the domain is significant.

Frequently asked questions