Creating Gypsum Mouldings

Using the moulding form described in the previous post, the following describes the production of gypsum mouldings.

 Prepare work table: A smooth table will provide a clean release of the moulding.  Attache straight guides a comfortable working distance from the edge of the table.  Also prepare a trough to collect the waste.

Tables with a scratched surface should be treated with a soup-water mix to facilitate release of the moulding.

 Draw out the margins of the moulding.

 This will provide a guide as to where to apply material.

 Attach a string in the center between the two lines.  The string provides tensile strength.

 Soak form.

 Mix gypsum: add 600ml of water to a container. 

 Slowly add gypsum until the powder reaches the water's surface.

Allow the gypsum to slowly soak up the water without stirring.

 

 If needed, add more water.

 Mix gypsum without mixing in air, which would create air pockets or bubbles in the moulding.

 Apply material over the edge of the table.  As the gypsum hardens, this will anchor the moulding so that it does not move when being pulled.

 

Apply material over string, between lines.

Pull form along guide, over material. 

 

 Move material onto moulding using a scraper or spatula.

  

Clean

 Repeat mixing and pouring

 

And continue pulling

The process in time lapse.

 

 After completion, cut the edges of the moulding with a utility knife to remove any bond with surrounding gypsum.

 Press down on the table with a hammer handle to loosen the bond with table.

 Completed mouldings

Gypsum Mouldings: Creating the Moulding Form

A moulding is a strip of material, often wood or plaster, with various profiles used to cover transitions between surfaces or for decoration.
The following describes the creation of moulding form:

 A metal sheet will be cut to create moulding.

 Draw the profile of the desired mould on paper and tape the paper to the metal plate.  In this case, the moulding is 60mm x 30mm, and modeled after the classical moulding Cyma Reversa.

 

 Using a jigsaw, cut out the form of the moulding

 

 Cut metal sheet

 file the edges of the metal sheet to prevent injury and to eliminate any spurs that might streak the moulding.

 Trace the moulding on a block of wood

 Draw an additional line 5mm outside the line of the moulding design.

 Cut out the moulding at an angle.

 Sand the wood with sandpaper

 Punch holes in the plate and attache with nails.

 Moulding form

 Attach the moulding form to an anchoring board.

Ensure the moulding form and anchoring board are perpendicular.

Attach diagonal bracing to maintain 90 degrees

The next post describes the actual creation of a gypsum moulding using the above form.

Pouring Gypsum Molds

Although gypsum is not found naturally in Japan, over the past 100 years Japanese plastering has adapted the use of gypsum plasters and gypsum molds.  The following are examples of poured gypsum molds featured at the Kyoto Plastering Institute.

 

 An imprint

  Student's mold

The following is a description of pouring simple gypsum molds.  In subsequent posts, more elaborate moldings will be discussed:
1. Create the form with clay. 

 In this case, a clay mixed with oil is used. 

 The oil inhibits the clay from drying and provides easier release from the silicone mold.

2. Spray the clay mold and board with a lacquer spray to improve release.

3. Cover the clay mold with a silicone gel that hardens with the addition of a hardener.

 Silicone

 Hardening Agent: Add half a bottle of hardening agent to one can (1kg) of silicone

 Mix thoroughly

 4. Cut the edges of the silicone mold for easy release from a gypsum mold, and create a wooden framework around the silicone mold.

 5. Mix gypsum to pour into the form work

 Fill a bowl half with water and add gypsum powder until the powder comes to the surface of the water.  Allow the gypsum to sit and slowly absorb the water.

 Mix thoroughly, removing any clumps but being careful not to mix in air.
6. Pour gypsum into form-work.

 7. Remove clay mold

8. Mix and pour gypsum into silicone mold.

 9. Carefully remove mold after cooling.

Bending neither to the rain

bending neither to the rain

nor to the wind

nor to the snow nor summer heat

firm in body, yet

unfettered by desire

never losing one’s temper

and always quietly smiling

eating four cups of brown rice

with miso soup and a few vegetables each day

in all maters

putting oneself last

watching and listening, and understanding

and never forgetting

in the shade of a pine grove

living in a small thatch hut

if there is a sick child in the east

he goes and tends him

if there is a tired mother in the west

he goes and shoulders her load

if someone is dying in the south,

he goes and calms their fears

if there is a quarrel to the north,

he goes and demands they put an end to their pettiness

during times of drought, he sheds tears

in cool summers, fearing for the harvest, he walks nervously

considered a fool by all

neither praised

nor blamed

such a person

I long to be

                    --Miyazawa Kenji (1896-1933)

After Miyazawa Kenji's death, a black notebook was found in the lid of his trunk.  It was filled with the repeated copy of a Buddhist prayer, "namu myoho renge kyo", a verse from the Lotus Sutra. Amongst the repeated mantra, the above poem was written.  It dates, November 6, 1931, a time in Miyazawa Kenji's life when he was quite ill.

Miyazawa Kenji was a social activist, writer and teacher who dedicated his life to rural farmers.

竹小舞・土壁塗りワークショップ

美山里山舎が竹小舞・土壁塗りワークショップを主催します。

  石場建てという日本の伝統軸組工法で建てた構造に竹小舞をかけて、荒壁土を塗ります。興味のある方、是非ご参加ください。

日時：11月中　水曜日～土曜日　9時～17時（途中参加可能）
場所：兵庫県丹波市春日町中山
地図
事前申し込みが必要です。
カイルまでご連絡ください。
nihondaigaku.kairu*gmail.com (*=@)
080-3477-9841

 大工さんの指示に沿ってワークショップを行います。

 海外の方も参加します。