Sand mold casting and Plaster mold casting are often mentioned as being similar to each other. With a production process that is incredibly similar, it’s no wonder that these two processes are often described as likenesses of each other. But if you’re going to put money into a casting process you’d probably like to know the difference between the two, right? If that’s the case then continue reading because today we’re going to differentiate between the two processes as well as examine the benefits and drawbacks of both methods.
Sand mold casting is a process that been around for literally thousands of years, while plaster mold casting is the baby of the two procedures. The major difference between the two, as you have probably guessed, is that a sand casting is formed with sand and a plaster casting is formed with plaster. So what does this mean regarding the finished product?
A sand casting is more likely to produce a grainy, rougher surface finish due to the porous nature of the sand used in the process, while a plaster casting is generally said to have a smoother surface finish that is similar to a die casting finish. Plaster mold casting can generally only accommodate metals with lower melting temperatures like aluminum, magnesium, zinc, and copper due to the delicacy of the plaster. Sand casting is typically used for heavier metals such as iron, steel, bronze, or brass because the sand mold is capable of dealing with the higher melting temperatures of these metals.
Both means of casting are praised for being highly efficient and economical. Neither method creates much waste. Often, materials like unused or excess metals can be recycled for use in the next batch of products.
Plaster mold casting is a longer process than sand mold casting, and because of this, has its trademark smooth surface finish. This is due to the low thermal conductivity of the plaster which causes the metal to cool slowly. Due to the non-porous nature of the plaster mold, these molds are often used for designs that are more complex because of the plaster’s ability to yield thinner wall thicknesses than sand molds.
So what we see in the end is that there are numerous advantages for each product, while each also has their own handful of drawbacks. Sand casting is a quicker process that will work more effectively for product designs that are simple, whereas more intricate designs require a slower molding process like sand casting. In addition to this, if the product must be made of a heavier metal, such as steel, the sand casting method must be used, simply because the plaster mold cannot accommodate the heat from these metals.
Ultimately, it depends on what you are looking for in your product: heavy, tough, and unrefined (sand casting) versus elaborate, strong, and smooth (plaster casting). Whichever method you prefer, at K&H we have the know-how and the skills to produce the best product possible.