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Not realy metal casting but a mix of many disciplines. This gloriette has been design and built by my partner and I. It was a wedding gift for friend of us.

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Here are some pictures to illustrate that work. 
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There is only three little parts made by sand casting, they form the upper assembly hub.

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Charlotte made the stained glasses.

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Molding is the operation that produce the mold cavity thank to a pattern.

Today, I’m asked for a spare part for a John Deere 4650. The front axle pivot was damaged by friction :

The aim is to obtain a part which will fit in the void and prevent further damage of the pin or the bore.

In order to built the mold we need a pattern. This is a part that look like the wanted one but is not made of the same material. In this case I use a two compounds silicone past that I force into the void. After it hardens,  I’v got my pattern:

Moulage en silicone bi-composant du logement de pivot usé

For economical purpose, the today’s part will share its mold with an other one. It is a replica of a casted part.

Les deux modèles moulés aujourd'huiToday’s patterns

A classical material for metal casting mold is silica sand (SiO2). Indeed it has many advantages, the first one :  it’s refractory. But sand alone is not consistent. That’s why it is added with bounding agent. In this case it is oligo-clay and oil. This mixture becomes very constant when rammed in a flask, and can be recycled at 90%.

The two patterns are set into a flask and powdered with talc.

Modèles et châssis
Talcage

They are covered with sieved sand.

Tamisage du sable de contact

Ramming begins with fingers.

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After the first contact layer, I add sand (no need to be sieved) and use the rammer.

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This operation has to be performed in a spiral way, from sides to center. Otherwise the sand is not well rammed.

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The operation is repeated until rammed sand level is higher than the flask. Then I use a flat rammer. A mallet will also do a good work.

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I finish with leveling the sand with a corner iron.

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The flask is turned over.

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I carve the sand in order to found the parting line.

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The sand is powdered with talc and the “drop” or upper flask is set up and filled with sand exactly the same way than the drag.

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The the mold is opened in order to remove pattern and carve sprue, runners, gates, risers, vent holes…

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The mod is blowed to remove sand grain, and closed.

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melting is an other article

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After shake out, here are the parts, with ingots of exeding metal and patterns:

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And finally, our John Deere is repaired.

Montage de la pièce finie