Introduction: How to Make a Crucible

By Dural Metalurg

In this short review I want to share my experience in making steel crucibles. I'm just a beginner in melting stuff, so I made only 2 different crucibles. First one is very simple and I practicaly didn't use any tools, the second one is more complex.

Step 1: How to Make a Simple Crucible Using a Tin Can

First one is really “Simple”. I’m sure that many people make such things, so I only wanted to show how I did this. If you don’t have tools or time it can be useful for you. Nevertheless, everything is much easier with tools but if you don’t have even multitool is enough.

For the first crucible we need:

· 1 tin can

· 2 bolts

· 4 nuts

· 4 split-ring lock washers

In addition to make a lid:

· piece of steel sheet (in my case I've found round steel piece)

· 1 bolt

· 1-2 nuts

That’s all we need.

Step 2: How to Make More Complex Crusible

Second crucible “More Complex” little harder to craft because we need some tools.

We need such tools:

· angle grinder;

· drill

· welder

In addition, we need such stuff for “More Complex” crucible:

· 1 piece of 50 mm (2 inches) pipe;

· 2 bolts;

· 1 rectangular piece of steel;

· piece of wire rod

To make a lid:

· piece of steel sheet;

· 1 long bolt;

· 4 nuts

· 4 washers

Step 3: Crucible Walls and a Bottom

I've found piece of 50 mm (2 inches) pipe. I thought that it would be enough for small aluminium quantities and was right about that. Also, I had to find something for the bottom and a piece of steel sheet (enough thick) fitted me fine.

Step 4: Welding the Bottom and Little "handle"

We should weld together pipe, steel plate and piece of wire rod (as a handle).

Step 5: Making Holes

Drilling holes for the side bolts and twisting them in. After that it's better to weld them.

Step 6: Last Stage

Making a lid. First of all I cuted out a lid from a piece of steel sheet using an angle grinder. The hardest thing on this stage is to bend a long bolt. You should avoid damaging the thread. I did this by turning several nuts while bending. After that turn 4 nuts and 4 washers (2 under and 2 above the lid) on the bolt and your lid is ready.

Step 7: Why I Had to Make More Complex Crucible

I have to make second, More Complex crucible because Simple just burned through during the first test. I’m still not sure why this happened. I have two ideas. First one is that tin cans have different thickness, so may be this one was to thin or may be the bottom was soldered not in the best way…

The second theory is that I have given too much air. The issue was that aluminium scrap melted, but slag still was in the form of these pieces. It maked me to continue increasing the temperature even when the scrap was melted. That’s why it can be my fault.

Step 8: Some Tips From My Short Experience

Finally, I’d like to recommend not to use a crucible from a can and try to make something using thicker steel (for example my second more complex crucible). If you don’t have such opportunity, at least not forget to control the temperature.