Green Sand, Green Sand Filter, and Green Sand Molding Information


casting is the most ancient form of metal casting and has been around since at
least Ancient Egypt. Many metal casters prefer using sand casting over many of
the other forms of processes because it’s cheap and the sand used is readily

Many experienced metal casters will continue to use sand casting even though
their abilities and resources allow them to use the other metal casting methods
like Lost Wax Casting or Investment Casting. Sand casting involves less
material and less effort than the other casting methods. Sand casting is a
great way for new casters to get into the trade.

In sand casting, the metal caster will create a mold by placing an original in
the flask which is filled with sand. The original will be a pattern of what you
want to cast. By ramming or vibrating the sand, the caster creates a mold of
the original. The casting sand used needs to be able to retain the shape of the
mold. Finding the right mixture of sand to water is crucial. Too much water can
ruin the mold and possibly destroy it while too little water will create a poor
casting. Green sand is a type of casting sand that many prefer since its
ability to retain the shape of the mold is far better then normal sand. Green
sand usually contains bentonite clay, sand, and water.

After the sand is packed, the pattern or original is removed carefully. Molten
metal is poured into the mold and allowed to cool. The metal caster will then
break the mold and dig out the casting.

While sand casting has its benefits the use of green sand can greatly increase
the likelihood of a successful casting. Green sand is not really green the
color refers to the damp nature of the sand. Green sand is created by
adding water and bentonite to the sand. One of the benefits of using bentonite
in green sand is that it makes the sand more permeable which allows more gas to

Metal casters can get the bentonite from a variety of sources like home
improvement stores and even from household resources. Many have milled the type
of cat litter that clumps since one of the ingredients is bentonite. Remember
to work in a well ventilated room or to wear proper face gear when working with
bentonite since it will irritate the lungs.

There are several recipes online for green sand but the most common method is
experimentation. What you are looking for when mixing the sand, water, and
bentonite is a texture that is not wet but damp and will retain its shape when

The type of sand you use to make green sand depends on you and the availability
of the sand. Many will use sand that they found out in the wilds of nature and
some will buy bags of sand like playground sand. As you cast with green sand
you will find out which works best with what metals.

Green sand is growing in popularity as more casters are recognizing the
properties of this method. If you have traditionally used regular sand casting,
green sand casting will prove to be easier to work with and will produce better

The best part about green sand casting is that is does not cost a lot of green.

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