20 replies to this topic

[Richard H]

evilgecko, could you please shrink down your signature? It's way too big!

[evilgecko]

A good way to make iron oxide is by electrolysis. Get two iron rods (such as what is used to reinforce concrete), and place them in a container of water with a bit of sulfuric acid or salt added to make the water conduct electricity. Make sure the two rods arn';t touching, and put 12V from a power pack across the two rods. Bubbles should form at both electrodes, with a greater amount at the negative electrode. Leave this going for about 2-3days untill water goes dark, goopy and murky. Using a coffe filter, filter out the particle of iron oxide and wash them with water. Dry untill they go brick red. This is good stuff to use as a burn rate catalyst, but cannot be used for making thermite. The most important thing is to watch that too much current is drawn from the power pack. I have blown a 500mA 12V power pack by placing the iron rods too close together. The water acts as a varible resistor, so make sure that they are far anough apart for the current to stay below what the power pack is rated at. A good way to see the current drawn is to use an anmetre. The rods may need to be moved closer together as more iron oxide is formed because iron oxide increases the resistance. To get maximum results but still maintaining a good safety margin is to keep the current about 100mA below the recommended maximum.

Hope this helps

[alany]

Or you could just buy it, considering it is less than $2 AUD per kg.

And you can buy it in red and black form, fairly pure, ultra fine and dry. I can't see any reason to make it beyond the challenge.

[evilgecko]

Chemicals arn't so easily obtained in New Zealand, and I often have to maker my own. Luckily potassium nitrate is such a widely used fertiliser

[alany]

Yeah I feel your pain, I am in Australia.

You'll find iron oxides in your local hardware store as cement pigments, almost always not labelled as iron oxides, but in the MSDS they are pure iron oxide. Some have it listed in tiny writing on the back.