Bracelet Metal/Sand Casting - Try-out Version

Introduction

Hi, I will show you how to design and create a bracelet with sand casting. Unfortunaly, the outcome isn't succesful, so I only show my process and reflection. Don't forget: Safety first!

What is Sand Casting?

Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. Molds made of sand are relatively cheap, and sufficiently refractory even for steel foundry use. In addition to the sand, a suitable bonding agent (usually clay) is mixed or occurs with the sand. The mixture is moistened, typically with water, but sometimes with other substances, to develop the strength and plasticity of the clay and to make the aggregate suitable for molding. The sand is typically contained in a system of frames or mold boxes known as a flask.

What do you need

3D printend design model
Sand for casting
Mold box
Pure aluminium scraps
Oven (up to 990 degree) or handheld heater
Leather clothes (see image)
Sand paper

Where to buy (Amazon):
Sand: https://www.amazon.com/slp/sand-casting/7bdy9vwgn...

Mold Box: https://www.amazon.com/2-Part-Flask-Casting-Jewel...

Sand Casting Kit: https://www.amazon.com/Casting-Deluxe-Crucible-Pow...

Step 1: Step 1: Prepare Your Design and Model

You can find the 3D files of the bracelet in the attachment, available in three sizes. You can directly send it to the 3D printer without any use of 3D modeling software. Tip: When you design your own bracelet, please keep you design as simple as possible. Sand casting is a rough creation process and not very accurate

Prepare your model
Please smoothen every corner, surfaces and edges of your bracelet with sandpaper

Step 2: Step 2: Adding Handles

Adding handles

I couldn't pull my bracelet from the mold, because a stamped the sand quite dense. So with a handheld 3D printer, I added some hairs which is easier to pull out from the mold boxes.

Step 3: Step 3: Mold Boxes With Casting Sand

Filling your mold boxes with casting sand

When you fill your box with sand, don't use your hands or fingers to fit into the box. Use a hammer or other tool which you can hit harder on the sand (keep the dense higher).

How to place your product into the mold box with sand
The bracelet don't need to be created in to two halves, because it's symetrical and easy to pull out. Place the bracelet entirely into the mold and make sure that every corner or edges are filled with sand

Step 4: Step 4: Preparing Molten Alumimium and Casting

How to melt aluminium

There are two methods to melt alumium: oven or a heater. Put all the scraps in into a steel cup, and heat it!

Beware: molten alumium cools down very quickly.

Oven: Please set up on 990 degree. When it's 830 - 870 degree, it's also suitable. Unfortunately, this is a slow process. When you open the oven, all heat go away, so you have to wait again.

Heater: This is a quick way for melting aluminium. No very accurate, but quick.

Casting
!!! FIRST WEAR YOUR PROTECTION CLOTHES !!!

While your pouring the aluminium, please scrap first the non molten layer on top.