Making a foundry core is not brain surgery. Provided you have the materials, the safety equipment and the know-how, it can be done in a garden shed. It's awesome what can be produced using a blowtorch, a bag of sand and hot metal. It can be a relaxing and productive pastime for the DIY enthusiast who has plenty of time and no deadlines to meet or targets to worry about. There is time to melt down and re-pour your mistakes until you are happy with the result.
If you have a small business casting metal, you don't have time for do-overs. If your foundry guy moves on to greener pastures, it can take a while to find someone with the same skill set and knowledge base. It's time to think about outsourcing your cores.
There are several types of core-making process. These are warm box, isocure, air set no-bake and shell. Each one has its own strengths. Nearly three quarters of all metal castings are produced using a sand casting process.
In the warm box process, furan is added to the sand as a fixative and heat provides the catalyst. Furan is a simple aromatic hydrocarbon, colorless. With a boiling point close to room temperature, the liquid is highly volatile and flammable. This is another compelling reason to outsource this work. The cores are heated until the exterior of the core is hard. The interior continues to cool once it is removed from the heat. This process is used to make cores with thin walls because they are resistant to being broken down or eroded by the molten metal.
Some times you want a mold that you can use to fabricate objects out of a non-ferrous materials, like fiberglass, styrofoam, plastic, and so on. This is where the air set no bake process comes in handy. This involved mixing sand and plastic together and packing it around a positive. Not only does this process give you the versatility you need, it can produce castings anywhere from 40 to 225 pounds in weight.
In the isocure process, the sand is mixed with a polyurethane resin. An amine gas or some other catalyst is injected into the box right before superheated air is forced through. This is a quick and cheap method for creating large cores.
When you are looking for a fine-grained finish, the shell process is the method of choice. Heat the casting box and pour in pre-treated sand. Apply heat to the outside to get a hard, thin shell. A side benefit of this approach is the sand on the interior remains uncured and can be reused.
Sand casting for foundry core production has been around since around 3,500 B. C.; that's way before even Moses walked the Earth. The reason it has stood the test of time is because of its reliability and versatility. Back in Moses' time, things were different and metal smiths had no problem melting down their mistakes. Over the years, the process has evolved in many different directions. It has always been a dangerous process. For many reasons, businesses today often outsource their foundry work.
If you have a small business casting metal, you don't have time for do-overs. If your foundry guy moves on to greener pastures, it can take a while to find someone with the same skill set and knowledge base. It's time to think about outsourcing your cores.
There are several types of core-making process. These are warm box, isocure, air set no-bake and shell. Each one has its own strengths. Nearly three quarters of all metal castings are produced using a sand casting process.
In the warm box process, furan is added to the sand as a fixative and heat provides the catalyst. Furan is a simple aromatic hydrocarbon, colorless. With a boiling point close to room temperature, the liquid is highly volatile and flammable. This is another compelling reason to outsource this work. The cores are heated until the exterior of the core is hard. The interior continues to cool once it is removed from the heat. This process is used to make cores with thin walls because they are resistant to being broken down or eroded by the molten metal.
Some times you want a mold that you can use to fabricate objects out of a non-ferrous materials, like fiberglass, styrofoam, plastic, and so on. This is where the air set no bake process comes in handy. This involved mixing sand and plastic together and packing it around a positive. Not only does this process give you the versatility you need, it can produce castings anywhere from 40 to 225 pounds in weight.
In the isocure process, the sand is mixed with a polyurethane resin. An amine gas or some other catalyst is injected into the box right before superheated air is forced through. This is a quick and cheap method for creating large cores.
When you are looking for a fine-grained finish, the shell process is the method of choice. Heat the casting box and pour in pre-treated sand. Apply heat to the outside to get a hard, thin shell. A side benefit of this approach is the sand on the interior remains uncured and can be reused.
Sand casting for foundry core production has been around since around 3,500 B. C.; that's way before even Moses walked the Earth. The reason it has stood the test of time is because of its reliability and versatility. Back in Moses' time, things were different and metal smiths had no problem melting down their mistakes. Over the years, the process has evolved in many different directions. It has always been a dangerous process. For many reasons, businesses today often outsource their foundry work.
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