Mold Preparation
Content
Procedures for making the shown product
using sand casting
Moulding box with pattern
board, base remove The moulding box is placed top
Pattern and runner in position
down with the pattern board sandwiched between drag and
cope. The base board is removed.
The pattern is placed on the pattern board along with the wooden plug that will form the
runner
Note the arrows showing the
orientation
Parting powder application
The pattern and runner are lightly
dusted with limestone flour which
Looking into the bottom of the
moulding box
The moulding box is now ready to receive the pattern
parting line to ease removal of the pattern from the sand without damage to the acts as
a
mould
First covering of sand
The first layer of the oil-bound moulding sand is sieved over the pattern to ensure a smooth finish without disturbing the parting
powder
Ramming
The moulding sand is rammed
down firmly, using an air rivetter with a fabricated footplate to ensure that the sand contains no
voids, and that
it will
bind
together for subsequent handling
Topping up
Once the first layer of moulding sand is pressed into the pattern
Strickling
by hand, the mould box is then
filled with sand
The sand is topped up and consolidated and then brought
the bottom of the box by strickling the sand off
back across
to flat
e
Ready to
turn
Top half removed The top of the moulding box
now removed
is
As Showing the whole box ready to turn. You can see the pattern
board between the two halves of the box
Turned The whole box is now inverted. Note the arrows showing the orientation. You can now see the top side of the pattern board
Pattern board removed
When the pattern board
is
removed the back of the oattern
and the runner former are visible.
You can also see the parting
powder on the sand
Replace top
Gates
The top
is now
replaced and
bolted down firmly
But first we need to place the gates which will connect the
runner to the pattern
Top in place
With the top bolted we are now almost ready to fill the second
half
Parting More parting powder so that the mould halves will separate cleanly and we can easily remove the
gate pieces
Sprue former
I use a short piece of plastic water
Undo
Unbolt the top from the bottom now comes the delicate bit!
pipe about 30mm diameter to form the sprue. lt is placed on the centre of the runner oiece and
held in position with a handfull of moulding sand
Lift and separate
Filled up
The top box is now carefully lifted
The top box is now filled and rammed just as the bottom box
was.
leaving the bottom box as it was previously
off
Rapping the top box
The gate pieces are rapped with
a
Top box
The underside of the top box now contains the gate pieces
bar to slightly loosen them in their
sand bed and then
removeo
carefullv
Sprue
Next the sprue piece is removed with a careful twisting and pulling motion
Funnelforming
On the outside face of the top box, the sprue hole is carefully enlarged to form a filling funnel
around 80mm diameter
25mm deep
and
h
Venting
To allow trapped gasses to escape
Runner piece removal
a pattern of small holes is formed through the sand in the top box to
the outside world
The runner piece is now rapped and removed. You can see the small wood screws being inserted and used as handles, just as they
are used on the oattern
gates.
and
Rapping the pattern
Now the pattern is rapped and removed. This also requires a
steady hand and a careful straight
Bottom box finished With the pattern and pieces all removed we can now give the
mould a last inspection and a very gentle blow out if any loose grains
have been disturbed
lift to avoid disturbing the sand
to remove any surface oxidation and impurity. lt is then removed from the furnace with a large pair of
stainless steel scraper
tongs and poured smoothly and steadily into the mould. Note the
gauntlets and leather apron
Close the box Now the top box is very carefully replaced. The cavity for the metal
is now completely formed. The two halves of the box are fitted with line-up pins so that the alignment remains consistent
every time the parts
assembled
are
Removed from the sand
After a 2 hour cooling period the casting is removed from the sand. Notice the shrinkage visible in the funnel area because there is no
riser and funnel acts as a riser
Pouring
When the brass is fully up to
temperature (about 1030 degrees C) the crucible is skimmed with a
using sand casting
Moulding box with pattern
board, base remove The moulding box is placed top
Pattern and runner in position
down with the pattern board sandwiched between drag and
cope. The base board is removed.
The pattern is placed on the pattern board along with the wooden plug that will form the
runner
Note the arrows showing the
orientation
Parting powder application
The pattern and runner are lightly
dusted with limestone flour which
Looking into the bottom of the
moulding box
The moulding box is now ready to receive the pattern
parting line to ease removal of the pattern from the sand without damage to the acts as
a
mould
First covering of sand
The first layer of the oil-bound moulding sand is sieved over the pattern to ensure a smooth finish without disturbing the parting
powder
Ramming
The moulding sand is rammed
down firmly, using an air rivetter with a fabricated footplate to ensure that the sand contains no
voids, and that
it will
bind
together for subsequent handling
Topping up
Once the first layer of moulding sand is pressed into the pattern
Strickling
by hand, the mould box is then
filled with sand
The sand is topped up and consolidated and then brought
the bottom of the box by strickling the sand off
back across
to flat
e
Ready to
turn
Top half removed The top of the moulding box
now removed
is
As Showing the whole box ready to turn. You can see the pattern
board between the two halves of the box
Turned The whole box is now inverted. Note the arrows showing the orientation. You can now see the top side of the pattern board
Pattern board removed
When the pattern board
is
removed the back of the oattern
and the runner former are visible.
You can also see the parting
powder on the sand
Replace top
Gates
The top
is now
replaced and
bolted down firmly
But first we need to place the gates which will connect the
runner to the pattern
Top in place
With the top bolted we are now almost ready to fill the second
half
Parting More parting powder so that the mould halves will separate cleanly and we can easily remove the
gate pieces
Sprue former
I use a short piece of plastic water
Undo
Unbolt the top from the bottom now comes the delicate bit!
pipe about 30mm diameter to form the sprue. lt is placed on the centre of the runner oiece and
held in position with a handfull of moulding sand
Lift and separate
Filled up
The top box is now carefully lifted
The top box is now filled and rammed just as the bottom box
was.
leaving the bottom box as it was previously
off
Rapping the top box
The gate pieces are rapped with
a
Top box
The underside of the top box now contains the gate pieces
bar to slightly loosen them in their
sand bed and then
removeo
carefullv
Sprue
Next the sprue piece is removed with a careful twisting and pulling motion
Funnelforming
On the outside face of the top box, the sprue hole is carefully enlarged to form a filling funnel
around 80mm diameter
25mm deep
and
h
Venting
To allow trapped gasses to escape
Runner piece removal
a pattern of small holes is formed through the sand in the top box to
the outside world
The runner piece is now rapped and removed. You can see the small wood screws being inserted and used as handles, just as they
are used on the oattern
gates.
and
Rapping the pattern
Now the pattern is rapped and removed. This also requires a
steady hand and a careful straight
Bottom box finished With the pattern and pieces all removed we can now give the
mould a last inspection and a very gentle blow out if any loose grains
have been disturbed
lift to avoid disturbing the sand
to remove any surface oxidation and impurity. lt is then removed from the furnace with a large pair of
stainless steel scraper
tongs and poured smoothly and steadily into the mould. Note the
gauntlets and leather apron
Close the box Now the top box is very carefully replaced. The cavity for the metal
is now completely formed. The two halves of the box are fitted with line-up pins so that the alignment remains consistent
every time the parts
assembled
are
Removed from the sand
After a 2 hour cooling period the casting is removed from the sand. Notice the shrinkage visible in the funnel area because there is no
riser and funnel acts as a riser
Pouring
When the brass is fully up to
temperature (about 1030 degrees C) the crucible is skimmed with a
