How to Make a Flask for Green Sand Casting

I’ve got some experience in melting metals such as aluminum and brass, so it was a time to try myself into casting. The only issue was where to pour liquid metal and how to make a form. The simplest way to make it was using green sand.

Although it should be the best way for casting, it demanded to make a flask.

Flask is a frame for the mould. It keeps all green sand inside. It consists of two parts:

1. Upper part is called a cope;

2. Under part is called a drag

To make a flask we need one long or several short planks. I decided to make a flask approx. 29 cm (11.5”) long, 25 cm (10”) wide and 10 cm (4”) high (2 parts x 5cm).

Firstly, I cut off 8 pieces of a plank and connected them by screws. I should mention that the better quality wood you take the less job you’ll have. In my case, I took boards from some package, so they were dry and enough straight but not from a nice wood and they were not grinded. Therefore, a lot of work should be done.

Secondly, I tried to make planks surface smoother. I took a drill with special attachment - sand paper. It’s important to make tight connection between a cope and a drag. I made them much smoother but not ideal.

The next was to add 3 strips for 2 sides of the flask. They would help to align and connect the cope and the drag.

I added two handles with 2 bolts to prevent flask opening during the molding.

I’ve just tested my flask. It works fine and I will show it in my next videos