Cast iron a well-known and quite commonly used iron-carbon alloy found mostly in the household and the industrial sector. From being used in machine parts, hand tools to being a significant part of cast iron skillets, this material is used in various ways. As a result, we gain plenty of benefits from cast iron, whether it’s in terms of being Strong, having microstructure alter, or easy to make and keep hot.
Altogether, we can say that cast iron is a widely used product in various manufacturing needs. However, with this wide use, cast iron also comes with being easily harmed with cracks and breaks. These cracks in cast iron can be caused due to the change in temperature, physical shock, or thermal gradient.
Considering this common issue that cast-iron faces, many opt for solving it through welding. That’s because welding techniques serve as a more reliable and widely chosen repairing solution for cast iron. However, welding can be a more complicated and extra damage-causing method too.
But, How to Fix Cast Iron Without Welding
Therefore, opting for a less hectic and suitable option is more important when it comes to repairing the cast iron without welding – so that it can serve effectively for a longer time.
Step-By-Step Brazing Method:
- Now to repair cast iron without welding, you have a more frequently trusted option of Brazing. This technique uses less heat in comparison to the welding technique. Therefore, this one serves as a more reliable option for repairing the cast iron cracks. So let’s go ahead and discover this method below.
- Firstly, you need to look for the right filler rod. You can make this decision by keeping in mind the main application of the cracked part of the cast iron. For the material, filler rods for cast iron brazing are made of either brass or nickel material. Additionally, when it comes to flux, you can choose a filler rock with the presence of instability or use change separately while performing the brazing technique.
- Next, you need to work on the surface of the cracks. For this, clean the damage in the cast iron properly before you start the Brazing that part of the cast iron. Properly clean and prepare this part so that all the impurities are removed from the surface.
- Now use a grinder to ground the crack in the cast iron so that a cross-section is formed in a U-shape. This would help the material used in Brazing to flow inside the released iron crack easily. As a result, this would avoid causing concentrations of the material in any specific part of the cast iron.
- Once you are done with the grinding work, use a brush (specifically of stainless steel) and brush the internal ground portion of the cast iron. This would help you eliminate the extra leftover particles that would have been produced during the grinding work.
- After this, start heating the cracked part of the cast iron. For this, try to avoid using a brazing torch, as it can cause further damaging or breaking of the cast iron (if used directly on its cold portion). Therefore, you can try using different heat sources like a gas grill, an oven, a weed burner, or any other similar means of heat. Through these, you will slowly heat the broken part of the cast iron – without causing any further damage or warping.
- Now, look if the piece of cast iron needs any bracing. If so, you need to place the amount of cast iron on a working surface. Often the large parts of the cast iron can require further heating while the Brazing is in process. This can be a case when the crack on the cast iron is large, and the brazing technique is taking a lot of time. If this is the case, or even not, you can make use of an external heater and keep the broken piece’s temperature maintained throughout by the process.
- Next, get a brazing torch and heat the cracks surfaces. Keep heating the body until it gets bright red. After this, place the filler rod inside the surface of the crack. When you do this, make sure that the temperature of the surface is hot enough to make the material of the filler rod flow easily inside the crack. Now to maintain the local temperature, use the brazing torch while the material progresses inside the gap.
- Lastly, you need to place the repaired part of the cast iron inside a sand container. Once it is placed inside, completely cover the fixed position with the sand. You need to keep this cast iron part in the sand for either one day or more (if the repaired part is larger). This step is highly essential after performing the brazing process. That’s mainly because if you leave the corrected part of the cast iron for cooling in the open air, it might face further cracks. Hence, it can be more useful to make it cool slowly inside the sand so that the repair can provide the cast iron with a durable and highly reliable end-result.
Now that you’ve kept the cast repaired part of the cast iron in the sand for one or more days, you will see that it has completely cooled down. Hence, it is fixed and back in shape for being used. So go ahead and start re-using the cast iron product.
Also, in case if you face any such cast iron cracks again, you’ve always got a better option than merely going for welding. So that’s nothing to worry about also. Now get working safely!